First Eocene lizard (Squamata) from Balkanatolia documents overwater dispersal of Paleogene pleurodontan iguanians

Georgios L Georgalis; Krister T Smith; Kevin D Mulcahy; Aidan Dunlay; Johan Knoff; Faruk Ocakoğlu; Alexis Licht; Grégoire Métais; K Christopher Beard

doi:10.1038/s41598-026-59284-2

. 2026 Jul 6;16:30840. doi: 10.1038/s41598-026-59284-2

First Eocene lizard (Squamata) from Balkanatolia documents overwater dispersal of Paleogene pleurodontan iguanians

Georgios L Georgalis ^1,^✉, Krister T Smith ^2,³, Kevin D Mulcahy ^4,⁵, Aidan Dunlay ⁵, Johan Knoff ⁵, Faruk Ocakoğlu ⁶, Alexis Licht ⁷, Grégoire Métais ⁸, K Christopher Beard ^4,⁵

PMCID: PMC13634911 PMID: 42409887

Abstract

We here describe a fossil jaw fragment from the middle Eocene (Lutetian) Uzunçarşıdere Formation in Anatolia, pertaining to a pleurodontan iguanian. This region during most of the Eocene was part of an isolated insular landmass, called Balkanatolia, that is mostly known for its peculiar and diverse insular mammalian fauna. The lizard specimen represents the first evidence of Eocene reptiles from Balkanatolia, providing a first glimpse into the herpetofaunas of this, now lost, insular landmass. The fossil material is rather fragmentary, precluding a more precise identification, but its distinctive tooth morphology confirms the presence of pleurodontan iguanians in the region for the first time. The presence of a distinct mesiodistal groove along the apical crest of the central cusp in the teeth of the Anatolian pleurodontan is of particular interest, as this feature is otherwise observed only in the Eocene genera Cadurciguana from Western Europe and Parasauromalus from North America, plus the extant American lineages of Dactyloidae, Leiocephalidae, and Polychrotidae. Interestingly, this feature seems to be absent from all other pleurodontans, including the abundant Eocene corytophanid Geiseltaliellus. The new find indicates another successful overseas dispersal of pleurodontans, a group that has repeatedly colonized distant landmasses, including oceanic islands, throughout its evolutionary history. Taking into consideration the diversity and abundance of pleurodontans in the Eocene of Europe and the total absence of the group from coeval Africa and Asia, it is likely that the new Anatolian iguana arrived from the former continent sometime between the early and early middle Eocene.

Keywords: Iguania, Pleurodonta, Anatolia, Biogeography, Dispersals

Subject terms: Ecology, Ecology, Evolution, Solid Earth sciences, Zoology

Introduction

Lizards have a fascinating biogeographic history, that encompasses an array of dispersal events, often including long marine barriers, as aptly demonstrated by the extant and fossil distribution of various groups, which includes even remote oceanic islands. Indeed, several lizard groups, from tiny gekkotans to large Monitor Lizards are known to be capable of long distance, overwater, dispersals, usually facilitated via rafting on “floating islands of vegetation”, a fact ultimately enabling them to colonize distant and remote terrains (e.g.,^1–8). Among the most successful lizard lineages regarding such overwater dispersals are pleurodontan iguanians (i.e., pleurodontans), which record not only the almost prosaic dispersals of anoles (Anolis) to and among Caribbean islands⁹ but also the longest suggested overwater dispersal among all terrestrial vertebrates (more than 8000 km), from North America to the Fiji Islands^1,8.

Pleurodonta (also known, depending on the applying terminology, as Pan-Iguanidae or Iguanidae sensu lato or Iguanoidea or Neoiguania [see below for notes on the nomenclature of the group]) represent a very diverse group of lizards^10–14. They are the sister group of Acrodonta (i.e., chameleons, agamas, spiny-tailed lizards, and their relatives), together comprising Iguania^10,15–17. Extant Pleurodonta have a rather disjunct and scattered geographic distribution, which comprises the Americas (including Caribbean and Galapagos Islands), Madagascar, and a few islands in Oceania^{5,7–10,12,18–20}. The fossil record implies an even broader distribution that also encompassed the Paleogene (and perhaps also the Late Cretaceous) of Europe and the Late Cretaceous of Asia (e.g., ^21–25). The disjunct extant distribution of pleurodontans, coupled with their broad fossil record across other continents, bears witness to a fascinating and rather complex evolutionary and biogeographic history of vicariance and overseas dispersal events^1,5,7,8,23.

Here we describe a fossil jaw fragment of a pleurodontan from the middle Eocene (Lutetian) of the Uzunçarşıdere Formation in Anatolia. This area, during the early and middle Eocene, was part of an isolated insular landmass, called Balkanatolia, that hosted a uniquely endemic mammal fauna^26–31. The Balkanatolian mammal fauna includes clades showing biogeographic affinities with each of the adjacent mainland faunas of Europe, Asia, and Africa. Several of these mammal clades diversified after colonizing Balkanatolia, possibly in response to iterative episodes of partial inundation of that isolated landmass^{26–30,32–35}. The new fossil specimen reported here represents the first reptile described from the insular fauna of Balkanatolia. It indicates another successful episode of overseas dispersal of pleurodontans during their evolutionary history. Biogeographic implications of the new find and the potential origin of the new pleurodontan are discussed.

Institutional abbreviations

EOU-UCF, fossil specimens from the Uzunçarşıdere Formation at Eskişehir Osmangazi University, Eskişehir, Türkiye; ISEA, Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Kraków, Poland; MNHN, Muséum national d’Histoire naturelle, Paris, France; MZUSP, Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil; SMF, Herpetology collection, Senckenberg Research Institute and Natural History Museum, Frankfurt am Main, Germany; SMF-ME, Messel vertebrate collection, Senckenberg Research Institute and Natural History Museum, Frankfurt am Main, Germany; SMF-PH, Paleoherpetology collection, Senckenberg Research Institute and Natural History Museum, Frankfurt am Main, Germany; UM, Institut des Sciences de l’Évolution, Université de Montpellier, Montpellier, France (formerly abbreviated as “USTL”).

Material and methods

The fossil material presented herein is permanently curated at the collections of Eskişehir Osmangazi University (Eskişehir, Türkiye). The material was collected from the AK-1 site of the Lülük Member of the Uzunçarşıdere Formation in the Orhaniye Basin of north-central Türkiye. No permits were required for the present study, which complied with all relevant regulations. For comparative purposes, multiple extant and extinct pleurodontan skeletons were studied at the collections of ISEA, MNHN, SMF-ME, SMF-PH, and UM. Scanning Electron Microscope (SEM) images of the fossil material were taken at the Microscopy and Analytical Imaging Research Resource Core Lab, University of Kansas, using a Hitachi S4700 Cold-Field Emission Scanning Electron Microscope.

Geological setting

The fossil material was collected from the Lülük Member of the Uzunçarşıdere Formation in the Orhaniye Basin of north-central Türkiye. The site that yielded the new lizard specimen is called AK-1. It is located near the village of Sarıbeyler in the Orhaniye Basin. Precise locality coordinates are maintained at the Division of Vertebrate Paleontology, University of Kansas Biodiversity Institute. These strata have been dated to the Lutetian (middle Eocene), approximately 44–43 Ma on the basis of magneto-stratigraphy and detrital zircon geochronology^31,36. This rock unit is well known for yielding a highly endemic mammalian fauna that includes anatoliadelphyid and herpetotheriid metatherians, pleuraspidotheriid “condylarths,” palaeoamasid embrithopods, palaeochiropterygid bats, and omomyid primates, among other taxa^{26,28,29,32,33,35,37,38}. During the early Paleogene, the Orhaniye Basin and broader Anatolia were part of a semi-continuous strip of land located along the Eurasian Neotethyan margin, between Western Europe and the Middle East, known as Balkanatolia^30,39 (see Fig. 1). Balkanatolia acted as an independent biogeographic province during the early and middle Eocene, and possibly during earlier times of the Paleogene^{26,27,29–31}. During the Paleocene and most of the Eocene, Balkanatolia was separated from other landmasses by narrow seaways and experienced numerous episodes of partial inundation^30,40, which favored the isolation of the regional fauna (Fig. 1). Balkanatolia fully emerged as a continuous landmass connected to Eurasia during the Bartonian, 40 to 38 million years ago; this geographical continuity paved the way for the arrival of Asia-derived mammals and the end of Balkanatolian endemism^30,34,39.

Fig. 1 — Map of the western Neotethys during the latest Lutetian, at the time of the Uzunçarşıdere Formation, modified from Montheil et al. (2026). Star indicates the position of the Uzunçarşıdere Formation.

Nomenclatural note on the usage of the name Pleurodonta

The traditional family Iguanidae (in the Linnean system) was critically examined by Frost & Etheridge¹⁰, who found no morphological evidence for the monophyly of the group (although they did not demonstrate paraphyly either). Hence, because (1) they insisted on monophyly in higher taxonomy, (2) the ICZN⁴¹ governs nomenclature only up to the family level, and (3) “iguanid” monophyly was in doubt, Frost & Etheridge¹⁰ elected to break up that taxon into eight families, each of which appeared to be monophyletic: Corytophanidae, Crotaphytidae, Hoplocercidae, Iguanidae, Opluridae, Tropiduridae, Phrynosomatidae, and Polychrotidae. They recognized the higher taxon Pleurodonta as encompassing these families (Pleurodonta, of course, was just as ambiguous as the traditional Iguanidae, but it was not formally speaking a “family”). Soon thereafter, molecular evidence for a monophyletic Iguanidae of traditional composition was presented⁴². Nevertheless, Frost et al.¹² doubled down on their taxonomic changes, citing “acceptance” of their taxonomy in the intervening years (and admittedly the general approach of elevating sub-familial ranks to family level has been extremely widely practiced in herpetology since then, even when the families that so arise have a single genus in them); their molecular analyses furthermore cast doubt on the monophyly of some of these new families, which led Frost et al.¹² to recognize a number of new family-level taxa: Leiocephalidae, Leiosauridae, Liolaemidae, Dactyloidae. These nomenclatural changes have been widely accepted^{7,8,13,15,43–46}. More recently, Vidal and Hedges⁴⁷ resurrected the name Iguanoidea to encompass all pleurodontan iguanians (see also⁴³), while de Queiroz et al.⁴⁸, applying the PhyloCode system, insisted on Iguanidae, for which Smith^16,17 defined the clade name Pan-Iguanidae. In any case, the name Pleurodonta has been widely accepted in recent herpetological (e.g., ^7,44–46,49) and palaeoherpetological (e.g., ^13,50–55) literature, and we follow this practice here.

Systematic palaeontology

Squamata Oppel, 1811⁵⁶

Iguania Cuvier, 1817⁵⁷

Pleurodonta Cope, 1864⁵⁸ (sensu¹²)

Pleurodonta indet.

Fig. 2

Material. A fragment of a jaw (EOC-UCF-15).

Description. The jaw fragment EOC-UCF-15 is highly incomplete, preserving only three teeth and one empty tooth position, plus part of the dental shelf (Fig. 2). It is unclear whether it represents part of a dentary or a maxilla. The dentition is pleurodont. Among the three preserved teeth, two are fully preserved and the third one is rather damaged and incomplete. The teeth are distinctly tricuspid; they possess a prominent central cusp and two weaker accessory cusps that are separated by apicobasal grooves from the central cusp both lingually and labially⁵⁹. A prominent, mesiodistal groove runs along the apical edge of the central cusp, dividing it into lingual and labial portions. The teeth are cylindrical and robust, with a relatively wide base. There is a slight inclination in the two well preserved teeth.

Results

Taxonomic attribution

The jaw fragment EOC-UCF-15 is most similar to those of pleurodontans based on the pleurodont dentition and the distinctly tricuspid teeth with a distinct central and two weaker accessory cusps^18,23,59. It is, however, possible that these characteristics are plesiomorphic for Iguania, in which case they do not provide any evidence for a relationship with Pleurodonta specifically^10,23. Furthermore, tricuspid teeth can occur in some Lacertoidea, namely certain members of teiids, lacertids, and gymnophthalmids (e.g., ^60–63). In lacertids and gymnophthalmids though the mesial accessory cusp usually appears before the distal accessory cusp, unlike in Pleurodonta, where the reverse is true. Τeiids have the base of the tooth often swollen and embedded inside a deposit of cementum (see⁶⁴); an apical groove is absent in all teiids we had available for study (Crocodilurus lacertinus MZUSP 92090; Tupinambis quadrilineatus MZUSP 84921; Tupinambis teguixin ISEA R/32, ISEA R/33, ISEA R/37, ISEA R/440, ISEA R/441, ISEA R/442, Salvator rufescens ISEA R/260, Ameivula ocellifera MZUSP 22341; Ameiva ameiva MZUSP 43047 [KTS, pers. obs.])—moreover, the posterior tricuspid teeth of teiids are also anteroposteriorly expanded (and not labiolingually), so they have a different form. In gymnophthalmids also, teeth of certain members of this group can possess distinct tricuspidity with lateral cusps much smaller than the medial one, however, this tricuspidity is confined to the posterior larger teeth and not to the anterior(most) ones, which are smaller and conical, and is overall different than the tricuspidity observed in pleurodontans (e.g.,^61,63). Tricuspidity can also appear in other, distantly related groups, e.g., species of the scincid genus Chioninia (with one species even approaching extreme multicuspid morphology; see⁶⁵) or some Cretaceous polyglyphanodontians (e.g.,⁶⁶), but they still differ from pleurodontans in the shape and size of the accessory cusps. As a further note, it has been suggested that certain members of Scincoidea (e.g., xantusiids) can also possess somehow tricuspid teeth, however, that “tricuspidity” (if this should be indeed termed as such) is usually faintly expressed, and the teeth do not have a central cusp separated from the accessory cusps by both labial and lingual grooves (e.g., ⁶⁰). Some characteristics of the tooth-bearing elements—a separation of the subnarial arterial and anterior superior alveolar foramina²³ and a wrapping of the splenial underneath the subdental shelf^23,24 might be synapomorphies that could help identify such incomplete remains, but the present Anatolian material is too fragmentary even for that. At the same time though, the alternatives are less plausible: Gymnophthalmidae and Teiidae are exclusively American (but see⁶⁷ for plausible Eocene occurrences of the latter from France); tricuspid Eocene Lacertidae are very rare, with tricuspidity being not prominent anyway (with accessory cusps being very small; e.g., ^68,69), while more lacertid taxa with even more “distinct” tricuspidity appear in the Oligocene (e.g., ^70–74).

Among extinct genera of Pleurodonta from Europe, EOC-UCF-15 shares the highest resemblance with Cadurciguana Augé⁷⁵, from the middle–late Eocene of France, particularly in terms of the robust and cylindrical teeth^55,62,75. The mesiodistal groove along the apical crest of the central cusp in EOC-UCF-15 is also present in Cadurciguana (uniquely among European pleurodontans) and, notably, the North American Parasauromalus sp. (see⁷⁶: fig. 8C), which Smith and Gauthier⁷⁶ considered a stem relative of the extant Polychrus. Amongst extant taxa this groove is present in all examined Dactyloidae, Leiocephalidae, and Polychrotidae (Anolis barbatus SMF 79164, Anolis carolinensis SMF-PH 593, Anolis conspersus SMF-PH 317, Anolis cuvieri SMF 60830, Anolis garmani SMF-PH 89, Anolis princeps SMF 66729, Anolis richardii SMF 65821, Anolis sagrei SMF-PH 386, Anolis serranoi SMF 78838, Leiocephalus carinatus SMF-PH 308 (Fig. 3c), and Polychrus acutirostris SMF 24870 (Fig. 3a–b)) but is absent in all examined members of other pleurodontan clades, viz. Corytophanidae, Crotaphytidae, Hoplocercidae, Iguanidae, Opluridae, Phrynosomatidae, and Tropiduridae (KTS and GLG, pers. obs.; Basiliscus plumifrons SMF-PH 595, Basiliscus vittatus SMF-PH 853, Chalarodon madagascariensis SMF 71025, Corytophanes cristatus SMF-PH 291 (Fig. 3e), Crotaphytus ?antiquus SMF-PH 286, Dipsosaurus dorsalis SMF-PH 296, Enyalioides oshaughnessyi SMF 67590 (Fig. 3d), Gambelia sp. SMF-PH 414, Laemanctus longipes SMF-PH 292, Laemanctus serratus SMF-PH 294, Oplurus cyclurus SMF 79191, Petrosaurus thalassinus SMF-PH 92, Phymaturus sp. SMF-PH 875, Sauromalus ater SMF-PH 1025, Sceloporus sp. SMF-PH 849). Sometimes a groove is found in the latter taxa on the lingual side of the mesial and distal carinae, but it does not extend apically over the central cusp. The apical groove is absent, to our knowledge, in the other lizard clades with tricuspid members (e.g., Lacertoidea). Thus, this apical groove provides the strongest evidence that EOC-UCF-15 is not just a pleurodontan iguanian but specifically could pertain to the total clades of Anolis, Leiocephalus, or Polychrus (Dactyloidae, Leiocephalidae, and Polychrotidae, respectively). Thus far, Dactyloidae and Leiocephalidae have never been described from Europe, but Smith et al.⁷⁷ ascribed an unnamed new species from Messel to the total clade of Polychrus. In contrast, the Eocene species Geiseltaliellus maarius Smith²³, from Messel (Fig. 3f) and Geiseltaliellus longicaudus Kuhn⁷⁸, from Geiseltal seem to be related to Corytophanidae^23,79.

Fig. 3 — Close up of teeth of selected extant pleurodontans and the Eocene *Geiseltaliellus maarius* from Messel, showing the presence (**a–c**) or absence (**d–f**) of the mesiodistal groove along the apical crest of the central cusp of the teeth. **a–b**) *Polychrus acutirostris* (left dentary SMF 24870) in dorsal (a) and posteromedial (b) views; c) *Leiocephalus carinatus* (left dentary SMF-PH 308) in posteromedial view; d) *Enyalioides oshaughnessyi* (left dentary SMF 67590) in posteromedial view; e) *Corytophanes cristatus* (left dentary SMF-PH 291) in medial view; f) *Geiseltaliellus maarius* (right maxilla of paratype SMF-ME 1769) in dorsal view. All photographs made by K.T.S.

Among the remaining extinct genera of Pleurodonta from Europe, EOC-UCF-15 differs from Bifurcodentodon Čerňanský, Smith, Smith and Folie⁵², from the earliest Eocene of Belgium in lacking the complex tooth morphology of the latter taxon, in which the central cusp is bifurcated, markedly split into two distinct and well-separated portions⁵². It further differs from Geiseltaliellus Kuhn⁷⁸, from the early–late Eocene of Germany, France, Belgium, Spain, and Portugal, in possessing more prominent central and accessory cusps, a groove on the apical edge of the central cusp, and generally more robust teeth^{23,62,64,80–82} (see Figs. 3f, 4d). It further differs from Phosphoriguana Lemierre & Georgalis⁵⁵ from the late Eocene of France, in having much more robust teeth and with different shape of the central and accessory cusps⁵⁵ (see Fig. 4e–g). It further differs from Pseudolacerta De Stefano⁸³, from the middle–late Eocene of France in its tricuspid teeth being more robust and with more prominent central and accessory cusps^55,62 (see Fig. 4a–c).

Discussion

Pleurodontans in Europe achieved a considerable diversity in the Eocene up to the late Oligocene^{23,52–55,75,80–82,84,85} (see Fig. 4), including beautifully preserved and articulated skeletons from the Fossillagerstätten localities of Messel and Geiseltal^{23,78,79,86–88} (see Fig. 4h–i). Pleurodontan fossils in Europe have been known since the second half of the nineteenth century^83,89–91, though they have been subject to a fascinating and perplexing history of taxonomic identifications, often being misidentified as other lizard groups (see detailed review in⁶⁹). They are entirely absent from Europe in the Paleocene, first appearing there during the earliest Eocene (MP 7); this absence implies that they only dispersed into Europe around the Paleocene–Eocene Thermal Maximum (PETM), together with a number of other immigrants, mainly from North America (see⁹²). However, the scarcity of European Paleocene localities that yielded herpetofaunal remains hinders any definite conclusions on the exact timing of their appearance in the continent. Few remains of pleurodontans (or stem pleurodontans) are also known from the Late Cretaceous of Europe (e.g.,²⁵), however, these pertain to different lineages than those known from the Paleogene, suggesting that the former forms apparently did not survive the K/Pg extinction event. Although they reached their highest diversity and abundance in Europe in the Eocene (e.g.,^{23,52,54,62,64}), pleurodontans survived the “Grande Coupure” and seem to have become locally extirpated at around the late Oligocene^84,85.

In contrast, the coeval Asian fossil record of pleurodontan iguanians is notoriously poor. Indeed, although the group has representatives in the Cretaceous of the continent, there is no unambiguous fossil occurrence in younger, Cenozoic, localities^8,17. Fossil taxa from the Paleocene of Mongolia that have been referred or at least considered close to pleurodontans (e.g.,^{21,22,24,93,94}) have alternatively been interpreted as being more distantly related^23,95 or even being of imprecise taxonomic affinities; there is thus no indication that pleurodontan iguanians survived the K/Pg extinction event in Asia⁷.

With regards to Africa, pleurodontans are absent from the extant herpetofauna of the continent, with the notable exception of Opluridae, which are endemic to the islands of Madagascar and Comoros (suggested, among others, to have arrived via a potential dispersal over Antarctica⁷). Pleurodontans are also notoriously absent from the African fossil record, apart from a few Quaternary remains of oplurids from Madagascar⁶⁰ and the Aldabra Atoll⁹⁶. Pleurodontans are also present on a few remote islands in Oceania^1,5,97,98 and Quaternary fossil remains indicate a higher (than today) insular diversity in this region (e.g., ⁴). Their highest diversity and abundance, on the other hand, is observed in the Americas, where the group is a ubiquitous element across faunas in North, Central, and South America, plus islands in the Caribbean and the Galapagos archipelago^9,10,18–20. The Americas also host their most abundant fossil record, with several taxa having been described, particularly from the Eocene of North America^{13,59,60,76,99–105}.

Squamates are well known to be capable of overwater dispersal, with several lizard and snake groups known to have reached distant landmasses, via rafting on “floating islands of vegetation” (also known in the literature as “floatons”, “flotsams”, “floatsomes”, “floating debris”, or “natural rafts”) (e.g., ^{1–8,106–110}). Pleurodontans are excellent at long distance, transoceanic dispersal, as is aptly demonstrated by their highly disjunct modern geographic distribution, which even encompasses some remote oceanic islands^{1,5,7,8,97,98,106,107,111,112}. Notably, such extreme cases include the most spectacular example of long-distance oceanic dispersal in the history of terrestrial vertebrates: the iconic extant pleurodontan Brachylophus from Fiji, the ancestors of which are thought to have rafted more than 8000 km from North America during the late Paleogene⁸. Such high marine dispersal capabilities of pleurodontans are not only inferred by their disjunct current and fossil distribution including insular areas in the Caribbean and the Galapagos¹¹³, but also from several direct observations of floating or even swimming by extant individuals (e.g., ^114,115), including cases of animals that floated for hundreds of kilometers and successfully colonized islands². Dispersals made by eggs (and not directly the animals themselves) have also been proposed, as certain pleurodontan taxa are characterized by a very long egg incubation (e.g., more than nine months in Brachylophus) (see ^1,5). It is also characteristic that the extant diversity of pleurodontans includes a plethora of insular endemics, apparently reflecting the amazing overseas dispersal capabilities of the group^{1,5,7–9,19,111}. Indeed, abundant extant insular endemic species of Leiocephalus, Anolis, Iguana, and Cyclura inhabit different Caribbean Islands and different species of tropidurids occur in the Galapagos Islands^{9,10,18,19,107,111}, while fossil and subfossil remains from a number of islands also attest to the presence of additional, now extinct, insular endemic species (e.g.,^4,116–118).

The identification of the new fossil material from the middle Eocene (44–43 Ma) Uzunçarşıdere Formation in Anatolia further indicates another successful overseas dispersal for pleurodontans: the colonization of insular Balkanatolia. The insular fauna of Balkanatolia presents a mosaic of taxa of European, Asian, and African affinities^26,27,32,38, which potentially originated via sweepstakes overseas dispersals^28,29,31. Balkanatolia remained isolated and insular until around the late Bartonian, at which time it became connected to Asia^30,34. In particular, the Uzunçarşıdere Formation is notable for its highly endemic mammalian fauna, with a unique composition of traditionally European, Asian, and African clades and evidence of several insular radiations^{26–30,32–35}. In addition, several placental mammal clades, namely Rodentia, Carnivora, Hyaenodonta, Perissodactyla, and Artiodactyla are entirely absent in the Orhaniye Basin (the depositional basin in which the Uzunçarşıdere Formation occurs), despite being dominant and diverse components in contemporary faunal assemblages elsewhere across Laurasia, further underscoring the unique insular character of the assemblage.

Insofar as pleurodontan iguanians probably originated in the New World¹⁶ and probably only dispersed to Europe in the earliest Eocene (e.g.,^52,104), it is evident that EOC-UCF-15 pertains to a so far unknown taxon which is the product of a dispersal event to Balkanatolia. The total absence of pleurodontans from the Paleogene of Asia and Africa renders Europe as the most likely source of origin for the Anatolian iguanian. It is reasonable to conclude that the ancestor of the Eocene Anatolian pleurodontan reached Balkanatolia via overwater dispersal (Fig. 5). Nevertheless, the incompleteness of the new Anatolian material hinders a more precise identification, and hence a more precise analysis of the biogeographic history of the lineage. The timing of this colonization remains poorly constrained, and we cannot infer precisely when this overseas dispersal event occurred, because the material from the Uzunçarşıdere Formation represents the only evidence substantiating the presence of pleurodontan iguanians in the Balkanatolian Archipelago. Taking into consideration, however, that pleurodontans first appeared in Europe in the earliest Eocene (MP 7), it is reasonable to assume that their dispersal to Anatolia could have occurred between the early and early middle Eocene. During the entire Eocene, including the interval of 44–43 Ma during which this new pleurodontan inhabited Balkanatolia, the distance separating Western Europe from the Balkanatolian archipelago remained relatively limited, on the order of 100 km^39,40.

Fig. 5 — Hypothetical life reconstruction of the ancestor of the new Anatolian pleurodontan. The lizard is envisaged here as standing at the edge of a tree trunk, part of a larger “floating island of vegetation” that is about to reach Balkanatolia. Artwork by Olha Timofieieva.

The Eocene was a time of intense dispersals for reptiles in the Old World, as is attested by numerous examples between Eurasia and Afro-Arabia, including also overwater dispersals (see discussion in¹¹⁹). However, there are no previous data concerning dispersal of reptiles to the isolated faunal province of Balkanatolia. As a matter of fact, Eocene herpetofaunas of Balkanatolia have been previously unknown: although a number of Oligo-Miocene reptiles are known from Anatolia^120–130, these all originate from much younger localities, at a time when this terrain was already connected to the Asian continent. It is therefore totally unknown whether reptiles dispersed to Balkanatolia in a fashion resembling that of mammals and also which reptile groups, if any, experienced endemic radiations there. Accordingly, despite its fragmentary condition, the new pleurodontan iguanian from the Uzunçarşıdere Formation provides a valuable glimpse into the herpetofaunas of a “Lost World”, the early Paleogene biogeographic province of Balkanatolia.

Acknowledgements

We would like to thank the Microscopy and Analytical Imaging Research Resource Core Lab, University of Kansas, for access to and assistance with imaging of the fossil material, using Hitachi S4700 Cold-Field Emission Scanning Electron Microscope. For access to comparative fossil material under their care, we are grateful to Nour-Eddine Jalil (MNHN) and Mehdi Mouana (UM). For photographs of Messel pleurodontans, we thank Anika Vogel (SMF-ME); for access to comparative extant material, we thank Hussam Zaher (MZUSP). We also thank Olha Timofieieva (ISEA) for preparing the life reconstruction of Figure 5. The quality of the paper was enhanced by useful comments provided by the Editor Krzysztof Stefaniak and the two Reviewers, Johannes Müller and an anonymous one.

Author contributions

G.L.G.: conceptualization, formal analysis, investigation, writing-original draft, writing-editing, photography of specimens, figure preparations; K.T.S.: formal analysis, investigation, writing-editing, photography of specimens; K.D.M.: sorting and preparation of fossil material, SEM imaging, investigation, writing-editing; A.D., sorting and preparation of fossil material, photography of specimens; J.K., sorting and preparation of fossil material, photography of fossil specimens; F.O., fieldwork, curation of fossil material; A.L., fieldwork, writing-editing; G.M., fieldwork, writing-editing; K.C.B., fieldwork, investigation, writing-editing. All authors have approved the submitted version.

Funding

G.L.G. acknowledges funding from the research project no. 2023/49/B/ST10/02631 financed by the National Science Center of Poland (Narodowe Centrum Nauki). Field work in the Uzunçarşıdere Formation has been supported by the US National Science Foundation (grants EAR-1543684 and EAR-2141115). This work was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Program (grant agreement No. 101043268) to A.L., grants from the U.S. National Science Foundation (EAR-1543684 and EAR-2141115) and the David B. Jones Foundation to K.C.B., and the National Geographic Society CRE GRANT #9215-12 to G.M.

Data availability

All data generated or analysed during this study are included in this published article.

Declarations

Competing interests

The authors declare no competing interests.

Footnotes

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

1.Gibbons, J. R. H. The biogeography of Brachylophus (Iguanidae) including the description of a new species, B. vitiensis, from Fiji. J. Herpet., 15, 255–273 (1981).
2.Censky, E. J., Hodge, K. & Dudley, J. Over-water dispersal of lizards due to hurricanes. Nature395, 553–554 (1998). [Google Scholar]
3.Carranza, S. & Arnold, E. N. Investigating the origin of transoceanic distributions: Mtdna shows Mabuya lizards (Reptilia, Scincidae) crossed the Atlantic twice. Syst. Biodivers.1, 275–282 (2003). [Google Scholar]
4.Pregill, G. K. & Worthy, T. A new iguanid lizard (Squamata, Iguanidae) from the Late Quaternary of Fiji, southwest Pacific. Herpetologica59, 57–67 (2003). [Google Scholar]
5.Keogh, J. S., Edwards, D. L., Fisher, R. N. & Harlow, P. S. Molecular and morphological analysis of the critically endangered Fijian iguanas reveals cryptic diversity and a complex biogeographic history. Philos. Trans. R. Soc. B363, 3413–3426 (2008). [DOI] [PMC free article] [PubMed] [Google Scholar]
6.Longrich, N. R., Vinther, J., Pyron, R. A., Pisani, D. & Gauthier, J. A. Biogeography of worm lizards (Amphisbaenia) driven by end-Cretaceous mass extinction. Proc. R. Soc. B282, 20143034 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
7.Welt, R. S. & Raxworthy, C. J. Dispersal, not vicariance, explains the biogeographic origin of iguanas on Madagascar. Mol. Phyl. Evol.167, 107345 (2022). [DOI] [PubMed] [Google Scholar]
8.Scarpetta, S. G. et al. Iguanas rafted more than 8,000 km from North America to Fiji. Proc. Natl. Acad. Sci. USA122, e2318622122 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]
9.Losos, J. Lizards in an Evolutionary Tree. Ecology and Adaptive Radiation of Anoles. University of California Press, 528 pp (2011).
10.Frost, D. R. & Etheridge, R. A Phylogenetic Analysis and Taxonomy of Iguanian Lizards (Reptilia: Squamata). Misc. Publ. Univ. Kans.81, 1–65 (1989). [Google Scholar]
11.McGuire, J. A. Phylogenetic systematics of crotaphytid lizards (Reptilia: Iguania: Crotaphytidae). Bull. Carnegie Mus. Nat. Hist.32, 1–143 (1996). [Google Scholar]
12.Frost, D. R. et al. Total evidence, sequence alignment, evolution of polychrotid lizards, and a reclassification of the Iguania (Squamata: Iguania). Am. Mus. Novit.3343, 1–38 (2001). [Google Scholar]
13.Scarpetta, S. G. Effects of phylogenetic uncertainty on fossil identification illustrated by a new and enigmatic Eocene iguanian. Sci. Rep.10, 15734 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]
14.Torres-Carvajal, O., de Queiroz, K. & Schulte, J. A. II. Iguanidae. In Phylonyms: A Companion to the PhyloCode (eds de Queiroz, K. et al.) 1158–1164 (CRC Press, 2020). [Google Scholar]
15.Townsend, T. M. et al. Phylogeny of iguanian lizards inferred from 29 nuclear loci, and a comparison of concatenated and species-tree approaches for an ancient, rapid radiation. Mol. Phyl. Evol.61, 363–380 (2011). [DOI] [PubMed] [Google Scholar]
16.Smith, K. T. Pan-Iguania Krister T. Smith, nomen cladi novum. In: de Queiroz, K., Cantino PD, & Gauthier JA, (eds). Phylonyms: A Companion to the PhyloCode. Boca Raton, Florida: CRC Press, pp. 1145–1147 (2020).
17.Smith, K.T. Pan-Iguanidae Krister T. Smith, nomen cladi novum. In: de Queiroz K, Cantino PD, & Gauthier JA, (eds). Phylonyms: A Companion to the PhyloCode. Boca Raton, Florida: CRC Press, pp. 1155–1157 (2020).
18.de Queiroz, K. Phylogenetic systematics of iguanine lizards: A comparative osteological study. Univ. Calif. Publ. Zool.118, 1–203 (1987). [Google Scholar]
19.Buckley, L. J. et al. A checklist of the iguanas of the world (Iguanidae; Iguaninae). In: Iverson, J. B., Grant, T. D., Knapp, C. R., & Pasachnik, S. A. (Eds.). Iguanas: Biology, Systematics, and Conservation. Herpetological Conservation and Biology, 11, 4–46 (2021).
20.Torres-Carvajal, O., Werneck, F. P., Fernandes, I. Y. & de Queiroz, K. Spiny tails and clades: a fully sampled phylogeny of hoplocercine lizards (Iguanidae/Hoplocercinae) and its taxonomic and nomenclatural implications. BPN1, 8–28 (2023). [Google Scholar]
21.Gao, K. & Norell, M. A. Taxonomic composition and systematics of Late Cretaceous lizard assemblages from Ukhaa Tolgod and adjacent localities, Mongolian Gobi Desert. Bull. Am. Mus. Nat. Hist.249, 1–118 (2000). [Google Scholar]
22.Conrad, J. L. Phylogeny and systematics of Squamata (Reptilia) based on morphology. Bull. Am. Mus. Nat. Hist.310, 1–182 (2008). [Google Scholar]
23.Smith, K. T. Eocene Lizards of the Clade Geiseltaliellus from Messel and Geiseltal, Germany, and the Early Radiation of Iguanidae (Reptilia: Squamata). Bull. Peabody Mus. Nat. Hist.50, 219–306 (2009). [Google Scholar]
24.Gauthier, J. A. et al. Assembling the squamate tree of life: perspectives from the phenotype and the fossil record. Bull. Peabody Mus. Nat. Hist.53, 3–308 (2012). [Google Scholar]
25.Jansen, O. et al. Freshwater amphibians and squamates from Villeveyrac (lower Campanian; Hérault, France): palaeodiversity, palaeoenvironment and implications for the Late Cretaceous palaeobiogeography of the European herpetofauna. Pap. Palaeontol.12, e70055 (2026). [Google Scholar]
26.Métais, G. et al. Eocene metatherians from Anatolia illuminate the assembly of an island fauna during deep time. PLoS ONE13, e0206181 (2018). [DOI] [PMC free article] [PubMed] [Google Scholar]
27.Métais, G. et al. Rapid colonization and diversification of a large-bodied mammalian herbivore clade in an insular context: New embrithopods from the Eocene of Balkanatolia. J. Mamm. Evol.31, 15 (2024). [Google Scholar]
28.Beard, K. C., Métais, G., Ocakoğlu, F. & Licht, A. An omomyid primate from the Pontide microcontinent of north-central Anatolia: Implications for sweepstakes dispersal of terrestrial mammals during the Eocene. Geobios66–67, 143–152 (2021). [Google Scholar]
29.Beard, K. C., Coster, P. M. C., Ocakoğlu, F., Licht, A. & Métais, G. Dental anatomy, phylogenetic relationships and paleoecology of Orhaniyeia nauta (Metatheria, Anatoliadelphyidae), a Gondwanan component of the insular Eocene mammal fauna of Balkanatolia (north-central Turkey). J. Mamm. Evol.30, 859–872 (2023). [Google Scholar]
30.Licht, A. et al. Balkanatolia: The insular mammalian biogeographic province that partly paved the way to the Grande Coupure. Earth-Sci. Rev.226, 103929 (2022). [Google Scholar]
31.Montheil, L. et al. Updating the timeline of faunal endemism in Balkanatolia, the biogeographic province connecting Europe, Asia and Africa. J. Asian Earth Sci.290, 106661 (2025). [Google Scholar]
32.Maas, M. C. et al. Enigmatic new ungulates from the early middle Eocene of central Anatolia, Turkey. J. Vert. Paleontol.21, 578–590 (2001). [Google Scholar]
33.Métais, G., Erdal, O., Erturac, M. K. & Beard, K. C. Tarsal morphology of the pleuraspidotheriid mammal Hilalia from the middle Eocene of Turkey. Acta Palaeontol. Pol.62, 173–179 (2017). [Google Scholar]
34.Métais, G., Coster, P., Licht, A., Ocakoğlu, F. & Beard, K. C. Additions to the late Eocene Süngülü mammal fauna in Easternmost Anatolia and the Eocene-Oligocene transition at the periphery of Balkanatolia. C. R. Palevol22, 711–727 (2023). [Google Scholar]
35.Jones, M. F. et al. A stem bat (Chiroptera: Palaeochiropterygidae) from the late middle Eocene of northern Anatolia: implications for the dispersal and palaeobiology of early bats. Palaeobiodiv. Palaeoenv.99, 261–269 (2019). [Google Scholar]
36.Licht, A. et al. Tectono-stratigraphy of the Orhaniye Basin, Turkey: implications for collision chronology and Paleogene biogeography of central Anatolia. J. Asian Earth Sci.143, 45–58 (2017). [Google Scholar]
37.Maas, M. C., Thewissen, J. G. M. & Kappelman, J. Hypsamasia seni (Mammalia: Embrithopoda) and other mammals from the Eocene Kartal Formation of Turkey. Bull. Carnegie Mus. Nat. Hist.34, 286–297 (1998). [Google Scholar]
38.Maga, A. M. & Beck, R. M. D. Skeleton of an unusual, cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44–43 million years ago) of Turkey. PLoS ONE12, e0181712 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
39.Montheil, L. et al. Across ancient oceans: Eocene dispersal routes of Asian terrestrial mammals to Europe, Afro-Arabia and South America. Earth-Sci. Rev.273, 105352 (2026). [Google Scholar]
40.Barrier, E., Vrielynck, B., Brouillet, J. & Brunet, M. Paleotectonic reconstruction of the central Tethyan realm. tectono‐sedimentary‐palinspastic maps from late Permian to Pliocene. CCGM/CGMW, Paris, Atlas 20 (2018).
41.ICZN [International Commission on Zoological Nomenclature]. International Code of Zoological Nomenclature. 4th ed. London: International Trust for Zoological Nomenclature, 306 pp (1999).
42.Macey, J. R. et al. Evolutionary shifts in three major structural features of the mitochondrial genome among iguanian lizards. J. Mol. Evol.44, 660–674 (1997). [DOI] [PubMed] [Google Scholar]
43.Daza, J. D. et al. Cladistic analysis of Iguania and a fossil lizard from the late Pliocene of northwestern Argentina. J. Herpetol.46, 104–119 (2012). [Google Scholar]
44.Streicher, J. W., Schulte, J. A. & Wiens, J. J. How should genes and taxa be sampled for phylogenomic analyses with missing data? An empirical study in iguanian lizards. Syst. Biol.65, 128–145 (2016). [DOI] [PubMed] [Google Scholar]
45.Zheng, Y. & Wiens, J. J. Combining phylogenomic and supermatrix approaches, and a time-calibrated phylogeny for squamate reptiles (lizards and snakes) based on 52 genes and 4162 species. Mol. Phyl. Evol.94, 537–547 (2016). [DOI] [PubMed] [Google Scholar]
46.Burbrink, F. T. et al. Interrogating genomic-scale data for Squamata (lizards, snakes, and amphisbaenians) shows no support for key traditional morphological relationships. Syst. Biol.69, 502–520 (2020). [DOI] [PubMed] [Google Scholar]
47.Vidal, N. & Hedges, B. S. The molecular evolutionary tree of lizards, snakes, and amphisbaenians. C. R. Biol.332, 129–139 (2009). [DOI] [PubMed] [Google Scholar]
48.Queiroz, K. de., Cantino, P. D. & Gauthier, J. A. Iguanidae T. Bell 1825 [O. Torres-Carvajal, K. de Queiroz and J. A. Schulte II], converted clade name. In: de Queiroz, K., Cantino, P. D., & Gauthier, J. A., (eds). Phylonyms: A Companion to the PhyloCode. Boca Raton, Florida: CRC Press, pp. 1159–1164 (2020).
49.Pyron, R. A., Burbrink, F. T. & Wiens, J. J. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evol. Biol.13, 93 (2013). [DOI] [PMC free article] [PubMed] [Google Scholar]
50.Jones, M. E. H. et al. Integration of molecules and new fossils supports a Triassic origin for Lepidosauria (lizards, snakes, and tuatara). BMC Evol. Biol.13, 208 (2013). [DOI] [PMC free article] [PubMed] [Google Scholar]
51.DeMar, D. G. Jr. et al. A new Late Cretaceous iguanomorph from North America and the origin of New World Pleurodonta (Squamata, Iguania). Proc. R. Soc. B284, 20161902 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]
52.Čerňanský, A., Smith, R., Smith, T. & Folie, A. Iguanian lizards (Acrodonta and Pleurodonta) from the earliest Eocene (MP 7) of Dormaal, Belgium: The first stages of these iconic reptiles in Europe. J. Vert. Paleont.42, e2184696 (2023). [Google Scholar]
53.Čerňanský, A., Tabuce, R. & Vidalenc, D. The first evidence of iguanians and scincoids from the lower Eocene of the Cos locality (Phosphorites du Quercy, France). J. Paleont.99, 430–440 (2025). [Google Scholar]
54.Čerňanský, A., Georgalis, G. L., Orliac, M. & Martin, J. E. The reptiles from the Lavergne locality of Phosphorites du Quercy in France show a high taxonomic diversity at the end of the late middle Eocene (MP 16). Swiss J. Palaeont.145, 343–401 (2026).
55.Lemierre, A. & Georgalis, G. L. Diversity in a greenhouse world: herpetofauna from the late Eocene (MP 17A) of La Bouffie, Quercy Phosphorites (Lot, SW France). Swiss J. Palaeont.144, 40 (2025). [Google Scholar]
56.Oppel, M. Die Ordnungen, Familien und Gattungen der Reptilien als Prodrom einer Naturgeschichte derselben 87 (Joseph Lindauer, Munich, 1811).
57.Cuvier, G. Le règne animal distribué d'après son organisation, pour servir de base à l'histoire naturelle des animaux et d’introduction à l'anatomie comparée. Tome II, contenant les reptiles, les poissons, les mollusques et les annélides 532 (Déterville, Paris, 1817).
58.Cope, E. D. On the characters of the higher Groups of Reptilia Squamata—and especially of Diploglossa. Proc. Acad. Nat. Sci. Philadelphia16, 224–231 (1864). [Google Scholar]
59.Smith, K. T. A diverse new assemblage of late Eocene squamates (Reptilia) from the Chadron formation of North Dakota, USA. Palaeontol. Electron.9 (5A), 1–44 (2006). [Google Scholar]
60.Estes, R. Sauria Terrestria, Amphisbaenia. In P. Wellnhofer (Ed.), Encyclopedia of Paleoherpetology, part 10a. Gustav Fischer Verlag 249 pp. (1983).
61.Bell, C. J., Evans, S. E. & Maisano, J. A. The skull of the gymnophthalmid lizard Neusticurus ecpleopus (Reptilia: Squamata). Zool. J. Linn. Soc.139, 283–304 (2003). [Google Scholar]
62.Augé, M. Évolution des lézards du Paléogène en Europe. Mém. Mus. Natl. Hist. Nat. Paris192, 1–369 (2005). [Google Scholar]
63.Torres-Carvajal, O., Parra, V., Sales Nunes, P. M. & Koch, C. A new species of Microtegu Lizard (Gymnophthalmidae: Cercosaurinae) from Amazonian Ecuador. J. Herpet., 55, 385–395 (2021).
64.Augé, M. Past and present distribution of iguanid lizards. Arch. Mus. Nac. (Rio de J.)65, 403–416 (2007).
65.Böhme, W., Schleich, H., Wipfler, B. & Koppetsch, T. On the dentition of the Cape Verdean endemic lizard genus Chioninia Gray, 1845, with a discussion of ecological implications in the giant species C. coctei (Duméril & Bibron, 1839) (Squamata, Scincidae). Spixiana45, 131–144 (2022).
66.Petermann, H. & Lyson, T. R. Squamate fauna from the Denver Basin shows major ecosystem disruption across K/Pg boundary. Proc. R. Soc. B292, 20251234 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]
67.Augé, M. L. & Brizuela, S. Transient presence of a teiid lizard in the European Eocene suggests transatlantic dispersal and rapid extinction. Palaeobiodiv. Palaeoenv.100, 793–817 (2020). [Google Scholar]
68.Čerňanský, A. & Augé, M. New species of the genus Plesiolacerta (Squamata: Lacertidae) from the upper Oligocene (MP 28) of southern Germany and a revision of the type species Plesiolacerta lydekkeri. Palaeontology56, 79–94 (2013). [Google Scholar]
69.Georgalis, G. L. & Čerňanský, A. Quo vadis Plesiolacerta? Taxonomy, nomenclature, and phylogenetic relationships of the large lacertid Plesiolacerta (Squamata) from the Palaeogene of Europe. Pap. Palaeontol.12, e70103 (2026).
70.Roček, Z. Lizards (Reptilia, Sauria) from the lower Miocene locality Dolnice (Bohemia, Czechoslovakia). Rozpravy Ceskoslovenské Akademie Ved, Rada Matematickych a prírodních Ved94, 3–69 (1984). [Google Scholar]
71.Arnold, E. N. Interrelationships and evolution of the East Asian Grass lizards, Takydromus (Squamata: Lacertidae). Zool. J. Linn. Soc.119, 267–296 (1997). [Google Scholar]
72.Venczel, M. & Hír, J. Lissamphibians and squamate reptiles from the early middle Miocene of Litke, Northern Hungary. Geobios48, 491–504 (2015). [Google Scholar]
73.Čerňanský, A. & Augé, M. L. The Oligocene and Miocene fossil lizards (Reptilia, Squamata) of Central Mongolia. Geodiversitas, 41, 811–839. (2019).
74.Georgalis, G. L., Villa, A., Ivanov, M., Vasilyan, D. & Delfino, M. Fossil amphibians and reptiles from the Neogene locality of Maramena (Greece), the most diverse European herpetofauna at the Miocene/Pliocene transition boundary. Palaeontol. Electronica, 22.3.68, 1–99 (2019).
75.Augé, M. Confirmation de la présence d’Iguanidae (Reptilia, Lacertilia) dans l’Eocène européen. C. R. Acad. Sci. Ser. II, 305, 633–636 (1987).
76.Smith, K. T. & Gauthier, J. A. Early Eocene lizards of the Wasatch Formation near Bitter Creek, Wyoming: diversity and paleoenvironment during an interval of global warming. Bull. Peabody Mus. Nat. Hist.54, 135–230 (2013). [Google Scholar]
77.Smith, K. T., Čerňanský, A., Scanferla, A. & Schaal, S. F. K. Lizards and snakes: warmth-loving sunbathers. In K. T. Smith, S. F. K. Schaal, & J. Habersetzer (Eds.), Messel: An Ancient Greenhouse Ecosystem. Schweizerbart, pp. 122–147 (2018).
78.Kuhn, O. Weitere Lacertilier, insbesondere Iguanidae aus dem Eozän des Geiseltales. PalZ23, 360–367 (1944). [Google Scholar]
79.Rossmann, T. Osteologische Beschreibung von Geiseltaliellus longicaudus Kuhn, 1944 (Squamata: Iguanoidea) aus dem Mittleren Eozän der Fossillagerstätten Geiseltal und Grube Messel (Deutschland), mit einer Revision der Gattung Geiseltaliellus. Palaeontogr., Abt. A, 258, 117–158 (2000).
80.Augé, M. La faune de Lézards et d’Amphisbaenes de l’Éocène inférieur de Condé-en-Brie (France). Bull. Mus. natl. hist. nat. Paris, 4e sér., 12, 111–141 (1990).
81.Rage, J.-C. & Augé, M. Amphibians and squamate reptiles from the lower Eocene of Silveirinha (Portugal). Ciências da Terra, Universidade Nova de Lisboa15, 103–116 (2003). [Google Scholar]
82.Bolet, A. First early Eocene lizards from Spain and a study of the compositional changes between late Mesozoic and early Cenozoic Iberian lizard assemblages. Palaeontol. Electronica, 20.2.20A, 1–22 (2017).
83.De Stefano, G. I sauri del Quercy appartenenti alla collezione Rossignol. Atti Soc. Ital. Sci. nat. Mus. Civ. Stor. nat. Milano, 42, 382–418 (1903).
84.Augé, M. L. & Pouit, D. Presence of iguanid lizards in the European Oligocene Lazarus taxa and fossil abundance. Bull. Soc. Géol. Fr.183, 653–660 (2012). [Google Scholar]
85.Čerňanský, A., Klembara, J. & Müller, J. The new rare record of the late Oligocene lizards and amphisbaenians from Germany and its impact on our knowledge of the European terminal Palaeogene. Palaeobiodiv. Palaeoenv.96, 559–587 (2016). [Google Scholar]
86.Smith, K. T. The squamation of the Eocene stem-basilisk Geiseltaliellus maarius (Squamata: Iguanidae: Corytophaninae) from Messel Germany. Salamandra53, 519–530 (2017). [Google Scholar]
87.Smith, K. T. & Wuttke, M. From tree to shining sea: taphonomy of the arboreal lizard Geiseltaliellus maarius. Palaeobiodiv. Palaeoenv.92, 45–65 (2012). [Google Scholar]
88.Smith, K. T. & Scanferla, A. Fossil snake preserving three trophic levels and evidence for an ontogenetic dietary shift. Palaeobiodiv. Palaeoenv.96, 589–599 (2016). [Google Scholar]
89.Filhol, H. Recherches sur les Phosphorites du Quercy. Étude des fossiles qu’on y rencontre et spécialement des mammifères. Pt. II. Ann. Sci. Géol., 8, 1–340 (1877).
90.Zittel, K. A. Handbuch der Palæontologie. I. Abteilung. Palæozoologie. III. Band. Pisces, Amphibia, Reptilia, Aves. Munchen and Leipzig: Druck und Verlag von R. Oldenbourg. 900 pp (1887–1890).
91.Lydekker, R. Catalogue of Fossil Reptiles and Amphibians in the British Museum (Natural History). Part I. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynchocephalia, and Proterosauria. London: British Museum (Natural History), 309 pp (1888).
92.Georgalis, G. L. & Mennecart, B. Another wanderer from the Paleocene-Eocene Thermal Maximum? A new species of the North American snake genus Cheilophis Gilmore, 1938 from the early Eocene of France. C. R. Palevol24, 317–331 (2025). [Google Scholar]
93.Alifanov, V. R. Lizards of the family Arretosauridae Gilmore, 1943 (Iguanomorpha, Iguania) from the Paleogene of Mongolia. Paleontol. J.46, 412–420 (2012). [Google Scholar]
94.Alifanov, V. R. Order Lacertilia. In Iskopaemye pozvonochnye Rossii i sopredel’nykh stran. Iskopaemye reptilii i ptitsy. Chast’ 2 (Fossil Vertebrates of Russia and Adjacent Countries: Fossil Reptiles and Birds: Part 2) (eds Kurochkin, E. N. & Lopatin, A. V.) 7–136 (Geos, Moscow, 2012).
95.Benson, R. B. J. et al. Mosaic anatomy in an early fossil squamate. Nature647, 673–679 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]
96.Arnold, E. N. Fossil reptiles from Aldabra Atoll, Indian Ocean. Bull. Br. Mus. Nat. Hist.29, 83–116 (1976). [Google Scholar]
97.Ineich, I. & Fisher, R. N. Rediscovery of the 220-year-old holotype of the Banded Iguana, Brachylophus fasciatus (Brongniart, 1800) in the Paris Natural History Museum. Zootaxa4138, 381–391 (2016). [DOI] [PubMed] [Google Scholar]
98.Fisher, R. N., Niukula, J., Watling, D. & Harlow, P. S. A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island. Fiji Islands. Zootaxa4273, 407–422 (2017). [DOI] [PubMed] [Google Scholar]
99.Cope, E. D. Synopsis of new Vertebrata from the Tertiary of Colorado: obtained during the summer of 1873. Washington D.C.: U.S. Government Printing Office 19 pp (1873).
100.Gilmore, C. W. The fossil lizards of North America. Mem. Natl. Acad. Sci.11, 1–197 (1928). [Google Scholar]
101.Holman, J. A. A herpetofauna from an early extension of the Harrison Formation (early Miocene, Arikareean), Cherry County. Nebraska. J. Vertebr. Paleontol.1, 49–56 (1981). [Google Scholar]
102.Smith, K. T. A new lizard assemblage from the earliest Eocene (zone Wa0) of the Bighorn Basin, Wyoming, USA: biogeography during the warmest interval of the Cenozoic. J. Syst. Palaeontol.7, 299–358 (2009). [Google Scholar]
103.Smith, K. T. The evolution of mid-latitude faunas during the Eocene: late Eocene lizards of the Medicine Pole Hills reconsidered. Bull. Peabody Mus. Nat. Hist.52, 3–105 (2011). [Google Scholar]
104.Smith, K. T. The long-term history of dispersal among lizards in the early Eocene: new evidence from a microvertebrate assemblage in the Bighorn Basin of Wyoming, USA. Palaeontology54, 1243–1270 (2011). [Google Scholar]
105.Conrad, J. L. A new Eocene Casquehead Lizard (Reptilia, Corytophanidae) from North America. PLoS ONE10, e0127900 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]
106.Cogger, H. G. Voyage of the banded iguana. Aust. Nat. Hist.18, 144–149 (1974). [Google Scholar]
107.Malone, C. L., Wheeler, T., Taylor, J. F. & Davis, S. K. Phylogeography of the Caribbean rock iguana (Cyclura): implications for conservation and insights on the biogeographic history of the West Indies. Mol. Phyl. Evol.17, 269–279 (2000). [DOI] [PubMed] [Google Scholar]
108.Raxworthy, C. J., Forstner, M. R. J. & Nussbaum, R. A. Chameleon radiation by oceanic dispersal. Nature415, 784–787 (2002). [DOI] [PubMed] [Google Scholar]
109.Georgalis, G. L. & Szyndlar, Z. First occurrence of Psammophis (Serpentes) from Europe witnesses another Messinian herpetofaunal dispersal from Africa—Biogeographic implications and a discussion of the vertebral morphology of psammophiid snakes. Anat. Rec.305, 3263–3282 (2022). [DOI] [PubMed] [Google Scholar]
110.Georgalis, G. L., et al. The world’s largest worm lizard: a new giant trogonophid (Squamata, Amphisbaenia) with extreme dental adaptations from the Eocene of Chambi, Tunisia. Zool. J. Linn. Soc., 202, zlae133 (2024).
111.Thorpe, R. S., Barlow, A., Surget-Groba, Y. & Malhotra, A. Multilocus phylogeny, species age and biogeography of the Lesser Antillean anoles. Mol. Phyl. Evol.127, 682–695 (2018). [DOI] [PubMed] [Google Scholar]
112.Ali, J. R. & Fritz, U. New twist to a fantastical distribution: Fiji-Tonga iguanas. TREE40, 536–538 (2025). [DOI] [PubMed] [Google Scholar]
113.Mulcahy, D. G. et al. Anthropogenic or natural dispersal: case of the Spiny-Tailed Iguanas (Ctenosaura) on Clarion Island. Mexico. Ecol. Evol.15, e72366 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]
114.Colosimo, G., Knapp, C. R., Wallace, L. E. & Welch, M. E. Inferred vs realized patterns of gene flow: an analysis of population structure in the Andros Island Rock Iguana. PLoS ONE9, e106963 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]
115.Knapp, C. R., Kessel, S. T., Parsons, G. & Iverson, J. B. Cyclura cychlura inornata (Allen Cays Rock Iguana) overwater dispersal. Herpetol. Rev.56, 78–79 (2025). [Google Scholar]
116.Etheridge, R. Fossil lizards from the Dominican Republic. Q. J. Fla. Acad. Sci.28, 1–24 (1965). [Google Scholar]
117.Pregill, G. K. Late Pleistocene herpetofaunas from Puerto Rico. Misc. Publ. Univ. Kans. Mus. Nat. Hist.71, 1–72 (1981). [Google Scholar]
118.Bochaton, C., Charles, L. & Lenoble, A. Historical and fossil evidence of an extinct endemic species of Leiocephalus (Squamata: Leiocephalidae) from the Guadeloupe Islands. Zootaxa4927, 383–409 (2021). [DOI] [PubMed] [Google Scholar]
119.Georgalis, G. L. First pan-trionychid turtle (Testudines, Pan-Trionychidae) from the Palaeogene of Africa. Pap. Palaeontol.7, 1919–1926 (2021). [Google Scholar]
120.Paicheler, J.-C. et al. 1978. Le bassin lacustre Miocène de Bes-Konak (Anatolie-Turquie): géologie et introduction à la paléontologie des vertébrés. Geobios, 11, 43–65 (1978).
121.Staesche, K., Karl, H.V. & Staesche, U. Fossile Schildkröten aus der Türkei. Geol. Jb., B, 98, 91–149 (2007).
122.Szyndlar, Z. & Hoşgör, I. Boine snake Bavarioboa from the Oligocene/Miocene of eastern Turkey with comments on connections between European and Asiatic snake faunas. Acta Palaeontol. Pol.57, 667–671 (2012). [Google Scholar]
123.Čerňanský, A. et al. First record of fossil anguines (Squamata; Anguidae) from the Oligocene and Miocene of Turkey. Swiss J. Geosci.110, 741–751 (2017). [Google Scholar]
124.Georgalis, G. L. & Joyce, W. G. A review of the fossil record of Old World turtles of the clade Pan-Trionychidae. Bull. Peabody Mus. Nat. Hist.58, 115–208 (2017). [Google Scholar]
125.Georgalis, G. L., Halaçlar, K., Mayda, S., Kaya, T. & Ayaz, D. First fossil find of the Blanus strauchi complex (Amphisbaenia, Blanidae) from the Miocene of Anatolia. J. Vertebr. Paleontol.38, e1437044 (2018). [Google Scholar]
126.Georgalis, G. L., Mayda, S., Alpagut, B., Şarbak, A. & Güler, G. The westernmost Asian record of pythonids (Serpentes): the presence of Python in a Miocene hominoid locality of Anatolia. J. Vertebr. Paleontol.40, e1781144 (2020). [Google Scholar]
127.Georgalis, G. L., Čerňanský, A. & Mayda, S. Late Paleogene herpetofaunas from the crossroads between two continents—new amphibian and reptile remains from the Oligocene of southern Balkans and Anatolia. C. R. Palevol20, 253–275 (2021). [Google Scholar]
128.Georgalis, G. L. et al. The antiquity of Asian chameleons—first potential Chamaeleonidae and associated squamate fauna from the Lower and Middle Miocene of Anatolia. J. Vertebr. Paleontol.42, e2160644 (2023). [Google Scholar]
129.Syromyatnikova, E., Georgalis, G. L., Mayda, S., Kaya, T. & Saraç, G. A new early Miocene herpetofauna from Kilçak, Turkey. Russ. J. Herpetol.26, 205–224 (2019). [Google Scholar]
130.Vasilyan, D., Roček, Z., Ayvazyan, A. & Claessens, L. Fish, amphibian and reptilian faunas from latest Oligocene to middle Miocene localities from Central Turkey. Palaeobiodiv. Palaeoenv.99, 723–757 (2019). [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

All data generated or analysed during this study are included in this published article.

[CR1] 1.Gibbons, J. R. H. The biogeography of Brachylophus (Iguanidae) including the description of a new species, B. vitiensis, from Fiji. J. Herpet., 15, 255–273 (1981).

[CR2] 2.Censky, E. J., Hodge, K. & Dudley, J. Over-water dispersal of lizards due to hurricanes. Nature395, 553–554 (1998). [Google Scholar]

[CR3] 3.Carranza, S. & Arnold, E. N. Investigating the origin of transoceanic distributions: Mtdna shows Mabuya lizards (Reptilia, Scincidae) crossed the Atlantic twice. Syst. Biodivers.1, 275–282 (2003). [Google Scholar]

[CR4] 4.Pregill, G. K. & Worthy, T. A new iguanid lizard (Squamata, Iguanidae) from the Late Quaternary of Fiji, southwest Pacific. Herpetologica59, 57–67 (2003). [Google Scholar]

[CR5] 5.Keogh, J. S., Edwards, D. L., Fisher, R. N. & Harlow, P. S. Molecular and morphological analysis of the critically endangered Fijian iguanas reveals cryptic diversity and a complex biogeographic history. Philos. Trans. R. Soc. B363, 3413–3426 (2008). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR6] 6.Longrich, N. R., Vinther, J., Pyron, R. A., Pisani, D. & Gauthier, J. A. Biogeography of worm lizards (Amphisbaenia) driven by end-Cretaceous mass extinction. Proc. R. Soc. B282, 20143034 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR7] 7.Welt, R. S. & Raxworthy, C. J. Dispersal, not vicariance, explains the biogeographic origin of iguanas on Madagascar. Mol. Phyl. Evol.167, 107345 (2022). [DOI] [PubMed] [Google Scholar]

[CR8] 8.Scarpetta, S. G. et al. Iguanas rafted more than 8,000 km from North America to Fiji. Proc. Natl. Acad. Sci. USA122, e2318622122 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR9] 9.Losos, J. Lizards in an Evolutionary Tree. Ecology and Adaptive Radiation of Anoles. University of California Press, 528 pp (2011).

[CR10] 10.Frost, D. R. & Etheridge, R. A Phylogenetic Analysis and Taxonomy of Iguanian Lizards (Reptilia: Squamata). Misc. Publ. Univ. Kans.81, 1–65 (1989). [Google Scholar]

[CR11] 11.McGuire, J. A. Phylogenetic systematics of crotaphytid lizards (Reptilia: Iguania: Crotaphytidae). Bull. Carnegie Mus. Nat. Hist.32, 1–143 (1996). [Google Scholar]

[CR12] 12.Frost, D. R. et al. Total evidence, sequence alignment, evolution of polychrotid lizards, and a reclassification of the Iguania (Squamata: Iguania). Am. Mus. Novit.3343, 1–38 (2001). [Google Scholar]

[CR13] 13.Scarpetta, S. G. Effects of phylogenetic uncertainty on fossil identification illustrated by a new and enigmatic Eocene iguanian. Sci. Rep.10, 15734 (2020). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR14] 14.Torres-Carvajal, O., de Queiroz, K. & Schulte, J. A. II. Iguanidae. In Phylonyms: A Companion to the PhyloCode (eds de Queiroz, K. et al.) 1158–1164 (CRC Press, 2020). [Google Scholar]

[CR15] 15.Townsend, T. M. et al. Phylogeny of iguanian lizards inferred from 29 nuclear loci, and a comparison of concatenated and species-tree approaches for an ancient, rapid radiation. Mol. Phyl. Evol.61, 363–380 (2011). [DOI] [PubMed] [Google Scholar]

[CR16] 16.Smith, K. T. Pan-Iguania Krister T. Smith, nomen cladi novum. In: de Queiroz, K., Cantino PD, & Gauthier JA, (eds). Phylonyms: A Companion to the PhyloCode. Boca Raton, Florida: CRC Press, pp. 1145–1147 (2020).

[CR17] 17.Smith, K.T. Pan-Iguanidae Krister T. Smith, nomen cladi novum. In: de Queiroz K, Cantino PD, & Gauthier JA, (eds). Phylonyms: A Companion to the PhyloCode. Boca Raton, Florida: CRC Press, pp. 1155–1157 (2020).

[CR18] 18.de Queiroz, K. Phylogenetic systematics of iguanine lizards: A comparative osteological study. Univ. Calif. Publ. Zool.118, 1–203 (1987). [Google Scholar]

[CR19] 19.Buckley, L. J. et al. A checklist of the iguanas of the world (Iguanidae; Iguaninae). In: Iverson, J. B., Grant, T. D., Knapp, C. R., & Pasachnik, S. A. (Eds.). Iguanas: Biology, Systematics, and Conservation. Herpetological Conservation and Biology, 11, 4–46 (2021).

[CR20] 20.Torres-Carvajal, O., Werneck, F. P., Fernandes, I. Y. & de Queiroz, K. Spiny tails and clades: a fully sampled phylogeny of hoplocercine lizards (Iguanidae/Hoplocercinae) and its taxonomic and nomenclatural implications. BPN1, 8–28 (2023). [Google Scholar]

[CR21] 21.Gao, K. & Norell, M. A. Taxonomic composition and systematics of Late Cretaceous lizard assemblages from Ukhaa Tolgod and adjacent localities, Mongolian Gobi Desert. Bull. Am. Mus. Nat. Hist.249, 1–118 (2000). [Google Scholar]

[CR22] 22.Conrad, J. L. Phylogeny and systematics of Squamata (Reptilia) based on morphology. Bull. Am. Mus. Nat. Hist.310, 1–182 (2008). [Google Scholar]

[CR23] 23.Smith, K. T. Eocene Lizards of the Clade Geiseltaliellus from Messel and Geiseltal, Germany, and the Early Radiation of Iguanidae (Reptilia: Squamata). Bull. Peabody Mus. Nat. Hist.50, 219–306 (2009). [Google Scholar]

[CR24] 24.Gauthier, J. A. et al. Assembling the squamate tree of life: perspectives from the phenotype and the fossil record. Bull. Peabody Mus. Nat. Hist.53, 3–308 (2012). [Google Scholar]

[CR25] 25.Jansen, O. et al. Freshwater amphibians and squamates from Villeveyrac (lower Campanian; Hérault, France): palaeodiversity, palaeoenvironment and implications for the Late Cretaceous palaeobiogeography of the European herpetofauna. Pap. Palaeontol.12, e70055 (2026). [Google Scholar]

[CR26] 26.Métais, G. et al. Eocene metatherians from Anatolia illuminate the assembly of an island fauna during deep time. PLoS ONE13, e0206181 (2018). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR27] 27.Métais, G. et al. Rapid colonization and diversification of a large-bodied mammalian herbivore clade in an insular context: New embrithopods from the Eocene of Balkanatolia. J. Mamm. Evol.31, 15 (2024). [Google Scholar]

[CR28] 28.Beard, K. C., Métais, G., Ocakoğlu, F. & Licht, A. An omomyid primate from the Pontide microcontinent of north-central Anatolia: Implications for sweepstakes dispersal of terrestrial mammals during the Eocene. Geobios66–67, 143–152 (2021). [Google Scholar]

[CR29] 29.Beard, K. C., Coster, P. M. C., Ocakoğlu, F., Licht, A. & Métais, G. Dental anatomy, phylogenetic relationships and paleoecology of Orhaniyeia nauta (Metatheria, Anatoliadelphyidae), a Gondwanan component of the insular Eocene mammal fauna of Balkanatolia (north-central Turkey). J. Mamm. Evol.30, 859–872 (2023). [Google Scholar]

[CR30] 30.Licht, A. et al. Balkanatolia: The insular mammalian biogeographic province that partly paved the way to the Grande Coupure. Earth-Sci. Rev.226, 103929 (2022). [Google Scholar]

[CR31] 31.Montheil, L. et al. Updating the timeline of faunal endemism in Balkanatolia, the biogeographic province connecting Europe, Asia and Africa. J. Asian Earth Sci.290, 106661 (2025). [Google Scholar]

[CR32] 32.Maas, M. C. et al. Enigmatic new ungulates from the early middle Eocene of central Anatolia, Turkey. J. Vert. Paleontol.21, 578–590 (2001). [Google Scholar]

[CR33] 33.Métais, G., Erdal, O., Erturac, M. K. & Beard, K. C. Tarsal morphology of the pleuraspidotheriid mammal Hilalia from the middle Eocene of Turkey. Acta Palaeontol. Pol.62, 173–179 (2017). [Google Scholar]

[CR34] 34.Métais, G., Coster, P., Licht, A., Ocakoğlu, F. & Beard, K. C. Additions to the late Eocene Süngülü mammal fauna in Easternmost Anatolia and the Eocene-Oligocene transition at the periphery of Balkanatolia. C. R. Palevol22, 711–727 (2023). [Google Scholar]

[CR35] 35.Jones, M. F. et al. A stem bat (Chiroptera: Palaeochiropterygidae) from the late middle Eocene of northern Anatolia: implications for the dispersal and palaeobiology of early bats. Palaeobiodiv. Palaeoenv.99, 261–269 (2019). [Google Scholar]

[CR36] 36.Licht, A. et al. Tectono-stratigraphy of the Orhaniye Basin, Turkey: implications for collision chronology and Paleogene biogeography of central Anatolia. J. Asian Earth Sci.143, 45–58 (2017). [Google Scholar]

[CR37] 37.Maas, M. C., Thewissen, J. G. M. & Kappelman, J. Hypsamasia seni (Mammalia: Embrithopoda) and other mammals from the Eocene Kartal Formation of Turkey. Bull. Carnegie Mus. Nat. Hist.34, 286–297 (1998). [Google Scholar]

[CR38] 38.Maga, A. M. & Beck, R. M. D. Skeleton of an unusual, cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44–43 million years ago) of Turkey. PLoS ONE12, e0181712 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR39] 39.Montheil, L. et al. Across ancient oceans: Eocene dispersal routes of Asian terrestrial mammals to Europe, Afro-Arabia and South America. Earth-Sci. Rev.273, 105352 (2026). [Google Scholar]

[CR40] 40.Barrier, E., Vrielynck, B., Brouillet, J. & Brunet, M. Paleotectonic reconstruction of the central Tethyan realm. tectono‐sedimentary‐palinspastic maps from late Permian to Pliocene. CCGM/CGMW, Paris, Atlas 20 (2018).

[CR41] 41.ICZN [International Commission on Zoological Nomenclature]. International Code of Zoological Nomenclature. 4th ed. London: International Trust for Zoological Nomenclature, 306 pp (1999).

[CR42] 42.Macey, J. R. et al. Evolutionary shifts in three major structural features of the mitochondrial genome among iguanian lizards. J. Mol. Evol.44, 660–674 (1997). [DOI] [PubMed] [Google Scholar]

[CR43] 43.Daza, J. D. et al. Cladistic analysis of Iguania and a fossil lizard from the late Pliocene of northwestern Argentina. J. Herpetol.46, 104–119 (2012). [Google Scholar]

[CR44] 44.Streicher, J. W., Schulte, J. A. & Wiens, J. J. How should genes and taxa be sampled for phylogenomic analyses with missing data? An empirical study in iguanian lizards. Syst. Biol.65, 128–145 (2016). [DOI] [PubMed] [Google Scholar]

[CR45] 45.Zheng, Y. & Wiens, J. J. Combining phylogenomic and supermatrix approaches, and a time-calibrated phylogeny for squamate reptiles (lizards and snakes) based on 52 genes and 4162 species. Mol. Phyl. Evol.94, 537–547 (2016). [DOI] [PubMed] [Google Scholar]

[CR46] 46.Burbrink, F. T. et al. Interrogating genomic-scale data for Squamata (lizards, snakes, and amphisbaenians) shows no support for key traditional morphological relationships. Syst. Biol.69, 502–520 (2020). [DOI] [PubMed] [Google Scholar]

[CR47] 47.Vidal, N. & Hedges, B. S. The molecular evolutionary tree of lizards, snakes, and amphisbaenians. C. R. Biol.332, 129–139 (2009). [DOI] [PubMed] [Google Scholar]

[CR48] 48.Queiroz, K. de., Cantino, P. D. & Gauthier, J. A. Iguanidae T. Bell 1825 [O. Torres-Carvajal, K. de Queiroz and J. A. Schulte II], converted clade name. In: de Queiroz, K., Cantino, P. D., & Gauthier, J. A., (eds). Phylonyms: A Companion to the PhyloCode. Boca Raton, Florida: CRC Press, pp. 1159–1164 (2020).

[CR49] 49.Pyron, R. A., Burbrink, F. T. & Wiens, J. J. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evol. Biol.13, 93 (2013). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR50] 50.Jones, M. E. H. et al. Integration of molecules and new fossils supports a Triassic origin for Lepidosauria (lizards, snakes, and tuatara). BMC Evol. Biol.13, 208 (2013). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR51] 51.DeMar, D. G. Jr. et al. A new Late Cretaceous iguanomorph from North America and the origin of New World Pleurodonta (Squamata, Iguania). Proc. R. Soc. B284, 20161902 (2017). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR52] 52.Čerňanský, A., Smith, R., Smith, T. & Folie, A. Iguanian lizards (Acrodonta and Pleurodonta) from the earliest Eocene (MP 7) of Dormaal, Belgium: The first stages of these iconic reptiles in Europe. J. Vert. Paleont.42, e2184696 (2023). [Google Scholar]

[CR53] 53.Čerňanský, A., Tabuce, R. & Vidalenc, D. The first evidence of iguanians and scincoids from the lower Eocene of the Cos locality (Phosphorites du Quercy, France). J. Paleont.99, 430–440 (2025). [Google Scholar]

[CR54] 54.Čerňanský, A., Georgalis, G. L., Orliac, M. & Martin, J. E. The reptiles from the Lavergne locality of Phosphorites du Quercy in France show a high taxonomic diversity at the end of the late middle Eocene (MP 16). Swiss J. Palaeont.145, 343–401 (2026).

[CR55] 55.Lemierre, A. & Georgalis, G. L. Diversity in a greenhouse world: herpetofauna from the late Eocene (MP 17A) of La Bouffie, Quercy Phosphorites (Lot, SW France). Swiss J. Palaeont.144, 40 (2025). [Google Scholar]

[CR56] 56.Oppel, M. Die Ordnungen, Familien und Gattungen der Reptilien als Prodrom einer Naturgeschichte derselben 87 (Joseph Lindauer, Munich, 1811).

[CR57] 57.Cuvier, G. Le règne animal distribué d'après son organisation, pour servir de base à l'histoire naturelle des animaux et d’introduction à l'anatomie comparée. Tome II, contenant les reptiles, les poissons, les mollusques et les annélides 532 (Déterville, Paris, 1817).

[CR58] 58.Cope, E. D. On the characters of the higher Groups of Reptilia Squamata—and especially of Diploglossa. Proc. Acad. Nat. Sci. Philadelphia16, 224–231 (1864). [Google Scholar]

[CR59] 59.Smith, K. T. A diverse new assemblage of late Eocene squamates (Reptilia) from the Chadron formation of North Dakota, USA. Palaeontol. Electron.9 (5A), 1–44 (2006). [Google Scholar]

[CR60] 60.Estes, R. Sauria Terrestria, Amphisbaenia. In P. Wellnhofer (Ed.), Encyclopedia of Paleoherpetology, part 10a. Gustav Fischer Verlag 249 pp. (1983).

[CR61] 61.Bell, C. J., Evans, S. E. & Maisano, J. A. The skull of the gymnophthalmid lizard Neusticurus ecpleopus (Reptilia: Squamata). Zool. J. Linn. Soc.139, 283–304 (2003). [Google Scholar]

[CR62] 62.Augé, M. Évolution des lézards du Paléogène en Europe. Mém. Mus. Natl. Hist. Nat. Paris192, 1–369 (2005). [Google Scholar]

[CR63] 63.Torres-Carvajal, O., Parra, V., Sales Nunes, P. M. & Koch, C. A new species of Microtegu Lizard (Gymnophthalmidae: Cercosaurinae) from Amazonian Ecuador. J. Herpet., 55, 385–395 (2021).

[CR64] 64.Augé, M. Past and present distribution of iguanid lizards. Arch. Mus. Nac. (Rio de J.)65, 403–416 (2007).

[CR65] 65.Böhme, W., Schleich, H., Wipfler, B. & Koppetsch, T. On the dentition of the Cape Verdean endemic lizard genus Chioninia Gray, 1845, with a discussion of ecological implications in the giant species C. coctei (Duméril & Bibron, 1839) (Squamata, Scincidae). Spixiana45, 131–144 (2022).

[CR66] 66.Petermann, H. & Lyson, T. R. Squamate fauna from the Denver Basin shows major ecosystem disruption across K/Pg boundary. Proc. R. Soc. B292, 20251234 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR67] 67.Augé, M. L. & Brizuela, S. Transient presence of a teiid lizard in the European Eocene suggests transatlantic dispersal and rapid extinction. Palaeobiodiv. Palaeoenv.100, 793–817 (2020). [Google Scholar]

[CR68] 68.Čerňanský, A. & Augé, M. New species of the genus Plesiolacerta (Squamata: Lacertidae) from the upper Oligocene (MP 28) of southern Germany and a revision of the type species Plesiolacerta lydekkeri. Palaeontology56, 79–94 (2013). [Google Scholar]

[CR69] 69.Georgalis, G. L. & Čerňanský, A. Quo vadis Plesiolacerta? Taxonomy, nomenclature, and phylogenetic relationships of the large lacertid Plesiolacerta (Squamata) from the Palaeogene of Europe. Pap. Palaeontol.12, e70103 (2026).

[CR70] 70.Roček, Z. Lizards (Reptilia, Sauria) from the lower Miocene locality Dolnice (Bohemia, Czechoslovakia). Rozpravy Ceskoslovenské Akademie Ved, Rada Matematickych a prírodních Ved94, 3–69 (1984). [Google Scholar]

[CR71] 71.Arnold, E. N. Interrelationships and evolution of the East Asian Grass lizards, Takydromus (Squamata: Lacertidae). Zool. J. Linn. Soc.119, 267–296 (1997). [Google Scholar]

[CR72] 72.Venczel, M. & Hír, J. Lissamphibians and squamate reptiles from the early middle Miocene of Litke, Northern Hungary. Geobios48, 491–504 (2015). [Google Scholar]

[CR73] 73.Čerňanský, A. & Augé, M. L. The Oligocene and Miocene fossil lizards (Reptilia, Squamata) of Central Mongolia. Geodiversitas, 41, 811–839. (2019).

[CR74] 74.Georgalis, G. L., Villa, A., Ivanov, M., Vasilyan, D. & Delfino, M. Fossil amphibians and reptiles from the Neogene locality of Maramena (Greece), the most diverse European herpetofauna at the Miocene/Pliocene transition boundary. Palaeontol. Electronica, 22.3.68, 1–99 (2019).

[CR75] 75.Augé, M. Confirmation de la présence d’Iguanidae (Reptilia, Lacertilia) dans l’Eocène européen. C. R. Acad. Sci. Ser. II, 305, 633–636 (1987).

[CR76] 76.Smith, K. T. & Gauthier, J. A. Early Eocene lizards of the Wasatch Formation near Bitter Creek, Wyoming: diversity and paleoenvironment during an interval of global warming. Bull. Peabody Mus. Nat. Hist.54, 135–230 (2013). [Google Scholar]

[CR77] 77.Smith, K. T., Čerňanský, A., Scanferla, A. & Schaal, S. F. K. Lizards and snakes: warmth-loving sunbathers. In K. T. Smith, S. F. K. Schaal, & J. Habersetzer (Eds.), Messel: An Ancient Greenhouse Ecosystem. Schweizerbart, pp. 122–147 (2018).

[CR78] 78.Kuhn, O. Weitere Lacertilier, insbesondere Iguanidae aus dem Eozän des Geiseltales. PalZ23, 360–367 (1944). [Google Scholar]

[CR79] 79.Rossmann, T. Osteologische Beschreibung von Geiseltaliellus longicaudus Kuhn, 1944 (Squamata: Iguanoidea) aus dem Mittleren Eozän der Fossillagerstätten Geiseltal und Grube Messel (Deutschland), mit einer Revision der Gattung Geiseltaliellus. Palaeontogr., Abt. A, 258, 117–158 (2000).

[CR80] 80.Augé, M. La faune de Lézards et d’Amphisbaenes de l’Éocène inférieur de Condé-en-Brie (France). Bull. Mus. natl. hist. nat. Paris, 4e sér., 12, 111–141 (1990).

[CR81] 81.Rage, J.-C. & Augé, M. Amphibians and squamate reptiles from the lower Eocene of Silveirinha (Portugal). Ciências da Terra, Universidade Nova de Lisboa15, 103–116 (2003). [Google Scholar]

[CR82] 82.Bolet, A. First early Eocene lizards from Spain and a study of the compositional changes between late Mesozoic and early Cenozoic Iberian lizard assemblages. Palaeontol. Electronica, 20.2.20A, 1–22 (2017).

[CR83] 83.De Stefano, G. I sauri del Quercy appartenenti alla collezione Rossignol. Atti Soc. Ital. Sci. nat. Mus. Civ. Stor. nat. Milano, 42, 382–418 (1903).

[CR84] 84.Augé, M. L. & Pouit, D. Presence of iguanid lizards in the European Oligocene Lazarus taxa and fossil abundance. Bull. Soc. Géol. Fr.183, 653–660 (2012). [Google Scholar]

[CR85] 85.Čerňanský, A., Klembara, J. & Müller, J. The new rare record of the late Oligocene lizards and amphisbaenians from Germany and its impact on our knowledge of the European terminal Palaeogene. Palaeobiodiv. Palaeoenv.96, 559–587 (2016). [Google Scholar]

[CR86] 86.Smith, K. T. The squamation of the Eocene stem-basilisk Geiseltaliellus maarius (Squamata: Iguanidae: Corytophaninae) from Messel Germany. Salamandra53, 519–530 (2017). [Google Scholar]

[CR87] 87.Smith, K. T. & Wuttke, M. From tree to shining sea: taphonomy of the arboreal lizard Geiseltaliellus maarius. Palaeobiodiv. Palaeoenv.92, 45–65 (2012). [Google Scholar]

[CR88] 88.Smith, K. T. & Scanferla, A. Fossil snake preserving three trophic levels and evidence for an ontogenetic dietary shift. Palaeobiodiv. Palaeoenv.96, 589–599 (2016). [Google Scholar]

[CR89] 89.Filhol, H. Recherches sur les Phosphorites du Quercy. Étude des fossiles qu’on y rencontre et spécialement des mammifères. Pt. II. Ann. Sci. Géol., 8, 1–340 (1877).

[CR90] 90.Zittel, K. A. Handbuch der Palæontologie. I. Abteilung. Palæozoologie. III. Band. Pisces, Amphibia, Reptilia, Aves. Munchen and Leipzig: Druck und Verlag von R. Oldenbourg. 900 pp (1887–1890).

[CR91] 91.Lydekker, R. Catalogue of Fossil Reptiles and Amphibians in the British Museum (Natural History). Part I. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynchocephalia, and Proterosauria. London: British Museum (Natural History), 309 pp (1888).

[CR92] 92.Georgalis, G. L. & Mennecart, B. Another wanderer from the Paleocene-Eocene Thermal Maximum? A new species of the North American snake genus Cheilophis Gilmore, 1938 from the early Eocene of France. C. R. Palevol24, 317–331 (2025). [Google Scholar]

[CR93] 93.Alifanov, V. R. Lizards of the family Arretosauridae Gilmore, 1943 (Iguanomorpha, Iguania) from the Paleogene of Mongolia. Paleontol. J.46, 412–420 (2012). [Google Scholar]

[CR94] 94.Alifanov, V. R. Order Lacertilia. In Iskopaemye pozvonochnye Rossii i sopredel’nykh stran. Iskopaemye reptilii i ptitsy. Chast’ 2 (Fossil Vertebrates of Russia and Adjacent Countries: Fossil Reptiles and Birds: Part 2) (eds Kurochkin, E. N. & Lopatin, A. V.) 7–136 (Geos, Moscow, 2012).

[CR95] 95.Benson, R. B. J. et al. Mosaic anatomy in an early fossil squamate. Nature647, 673–679 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR96] 96.Arnold, E. N. Fossil reptiles from Aldabra Atoll, Indian Ocean. Bull. Br. Mus. Nat. Hist.29, 83–116 (1976). [Google Scholar]

[CR97] 97.Ineich, I. & Fisher, R. N. Rediscovery of the 220-year-old holotype of the Banded Iguana, Brachylophus fasciatus (Brongniart, 1800) in the Paris Natural History Museum. Zootaxa4138, 381–391 (2016). [DOI] [PubMed] [Google Scholar]

[CR98] 98.Fisher, R. N., Niukula, J., Watling, D. & Harlow, P. S. A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island. Fiji Islands. Zootaxa4273, 407–422 (2017). [DOI] [PubMed] [Google Scholar]

[CR99] 99.Cope, E. D. Synopsis of new Vertebrata from the Tertiary of Colorado: obtained during the summer of 1873. Washington D.C.: U.S. Government Printing Office 19 pp (1873).

[CR100] 100.Gilmore, C. W. The fossil lizards of North America. Mem. Natl. Acad. Sci.11, 1–197 (1928). [Google Scholar]

[CR101] 101.Holman, J. A. A herpetofauna from an early extension of the Harrison Formation (early Miocene, Arikareean), Cherry County. Nebraska. J. Vertebr. Paleontol.1, 49–56 (1981). [Google Scholar]

[CR102] 102.Smith, K. T. A new lizard assemblage from the earliest Eocene (zone Wa0) of the Bighorn Basin, Wyoming, USA: biogeography during the warmest interval of the Cenozoic. J. Syst. Palaeontol.7, 299–358 (2009). [Google Scholar]

[CR103] 103.Smith, K. T. The evolution of mid-latitude faunas during the Eocene: late Eocene lizards of the Medicine Pole Hills reconsidered. Bull. Peabody Mus. Nat. Hist.52, 3–105 (2011). [Google Scholar]

[CR104] 104.Smith, K. T. The long-term history of dispersal among lizards in the early Eocene: new evidence from a microvertebrate assemblage in the Bighorn Basin of Wyoming, USA. Palaeontology54, 1243–1270 (2011). [Google Scholar]

[CR105] 105.Conrad, J. L. A new Eocene Casquehead Lizard (Reptilia, Corytophanidae) from North America. PLoS ONE10, e0127900 (2015). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR106] 106.Cogger, H. G. Voyage of the banded iguana. Aust. Nat. Hist.18, 144–149 (1974). [Google Scholar]

[CR107] 107.Malone, C. L., Wheeler, T., Taylor, J. F. & Davis, S. K. Phylogeography of the Caribbean rock iguana (Cyclura): implications for conservation and insights on the biogeographic history of the West Indies. Mol. Phyl. Evol.17, 269–279 (2000). [DOI] [PubMed] [Google Scholar]

[CR108] 108.Raxworthy, C. J., Forstner, M. R. J. & Nussbaum, R. A. Chameleon radiation by oceanic dispersal. Nature415, 784–787 (2002). [DOI] [PubMed] [Google Scholar]

[CR109] 109.Georgalis, G. L. & Szyndlar, Z. First occurrence of Psammophis (Serpentes) from Europe witnesses another Messinian herpetofaunal dispersal from Africa—Biogeographic implications and a discussion of the vertebral morphology of psammophiid snakes. Anat. Rec.305, 3263–3282 (2022). [DOI] [PubMed] [Google Scholar]

[CR110] 110.Georgalis, G. L., et al. The world’s largest worm lizard: a new giant trogonophid (Squamata, Amphisbaenia) with extreme dental adaptations from the Eocene of Chambi, Tunisia. Zool. J. Linn. Soc., 202, zlae133 (2024).

[CR111] 111.Thorpe, R. S., Barlow, A., Surget-Groba, Y. & Malhotra, A. Multilocus phylogeny, species age and biogeography of the Lesser Antillean anoles. Mol. Phyl. Evol.127, 682–695 (2018). [DOI] [PubMed] [Google Scholar]

[CR112] 112.Ali, J. R. & Fritz, U. New twist to a fantastical distribution: Fiji-Tonga iguanas. TREE40, 536–538 (2025). [DOI] [PubMed] [Google Scholar]

[CR113] 113.Mulcahy, D. G. et al. Anthropogenic or natural dispersal: case of the Spiny-Tailed Iguanas (Ctenosaura) on Clarion Island. Mexico. Ecol. Evol.15, e72366 (2025). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR114] 114.Colosimo, G., Knapp, C. R., Wallace, L. E. & Welch, M. E. Inferred vs realized patterns of gene flow: an analysis of population structure in the Andros Island Rock Iguana. PLoS ONE9, e106963 (2014). [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR115] 115.Knapp, C. R., Kessel, S. T., Parsons, G. & Iverson, J. B. Cyclura cychlura inornata (Allen Cays Rock Iguana) overwater dispersal. Herpetol. Rev.56, 78–79 (2025). [Google Scholar]

[CR116] 116.Etheridge, R. Fossil lizards from the Dominican Republic. Q. J. Fla. Acad. Sci.28, 1–24 (1965). [Google Scholar]

[CR117] 117.Pregill, G. K. Late Pleistocene herpetofaunas from Puerto Rico. Misc. Publ. Univ. Kans. Mus. Nat. Hist.71, 1–72 (1981). [Google Scholar]

[CR118] 118.Bochaton, C., Charles, L. & Lenoble, A. Historical and fossil evidence of an extinct endemic species of Leiocephalus (Squamata: Leiocephalidae) from the Guadeloupe Islands. Zootaxa4927, 383–409 (2021). [DOI] [PubMed] [Google Scholar]

[CR119] 119.Georgalis, G. L. First pan-trionychid turtle (Testudines, Pan-Trionychidae) from the Palaeogene of Africa. Pap. Palaeontol.7, 1919–1926 (2021). [Google Scholar]

[CR120] 120.Paicheler, J.-C. et al. 1978. Le bassin lacustre Miocène de Bes-Konak (Anatolie-Turquie): géologie et introduction à la paléontologie des vertébrés. Geobios, 11, 43–65 (1978).

[CR121] 121.Staesche, K., Karl, H.V. & Staesche, U. Fossile Schildkröten aus der Türkei. Geol. Jb., B, 98, 91–149 (2007).

[CR122] 122.Szyndlar, Z. & Hoşgör, I. Boine snake Bavarioboa from the Oligocene/Miocene of eastern Turkey with comments on connections between European and Asiatic snake faunas. Acta Palaeontol. Pol.57, 667–671 (2012). [Google Scholar]

[CR123] 123.Čerňanský, A. et al. First record of fossil anguines (Squamata; Anguidae) from the Oligocene and Miocene of Turkey. Swiss J. Geosci.110, 741–751 (2017). [Google Scholar]

[CR124] 124.Georgalis, G. L. & Joyce, W. G. A review of the fossil record of Old World turtles of the clade Pan-Trionychidae. Bull. Peabody Mus. Nat. Hist.58, 115–208 (2017). [Google Scholar]

[CR125] 125.Georgalis, G. L., Halaçlar, K., Mayda, S., Kaya, T. & Ayaz, D. First fossil find of the Blanus strauchi complex (Amphisbaenia, Blanidae) from the Miocene of Anatolia. J. Vertebr. Paleontol.38, e1437044 (2018). [Google Scholar]

[CR126] 126.Georgalis, G. L., Mayda, S., Alpagut, B., Şarbak, A. & Güler, G. The westernmost Asian record of pythonids (Serpentes): the presence of Python in a Miocene hominoid locality of Anatolia. J. Vertebr. Paleontol.40, e1781144 (2020). [Google Scholar]

[CR127] 127.Georgalis, G. L., Čerňanský, A. & Mayda, S. Late Paleogene herpetofaunas from the crossroads between two continents—new amphibian and reptile remains from the Oligocene of southern Balkans and Anatolia. C. R. Palevol20, 253–275 (2021). [Google Scholar]

[CR128] 128.Georgalis, G. L. et al. The antiquity of Asian chameleons—first potential Chamaeleonidae and associated squamate fauna from the Lower and Middle Miocene of Anatolia. J. Vertebr. Paleontol.42, e2160644 (2023). [Google Scholar]

[CR129] 129.Syromyatnikova, E., Georgalis, G. L., Mayda, S., Kaya, T. & Saraç, G. A new early Miocene herpetofauna from Kilçak, Turkey. Russ. J. Herpetol.26, 205–224 (2019). [Google Scholar]

[CR130] 130.Vasilyan, D., Roček, Z., Ayvazyan, A. & Claessens, L. Fish, amphibian and reptilian faunas from latest Oligocene to middle Miocene localities from Central Turkey. Palaeobiodiv. Palaeoenv.99, 723–757 (2019). [Google Scholar]

PERMALINK

First Eocene lizard (Squamata) from Balkanatolia documents overwater dispersal of Paleogene pleurodontan iguanians

Georgios L Georgalis

Krister T Smith

Kevin D Mulcahy

Aidan Dunlay

Johan Knoff

Faruk Ocakoğlu

Alexis Licht

Grégoire Métais

K Christopher Beard

Abstract

Introduction

Institutional abbreviations

Material and methods

Geological setting

Fig. 1.

Nomenclatural note on the usage of the name Pleurodonta

Systematic palaeontology

Fig. 2.

Results

Taxonomic attribution

Fig. 3.

Fig. 4.

Discussion

Fig. 5.

Acknowledgements

Author contributions

Funding

Data availability

Declarations

Competing interests

Footnotes

References

Associated Data

Data Availability Statement

ACTIONS

PERMALINK

RESOURCES

Similar articles

Cited by other articles

Links to NCBI Databases