Table 1. Overview of the Kimmeridgian-Lower Tithonian metriorhynchids species and a few of their dental characteristics.
| Species | Age | Country | Teeth ornamentation | Carinae | Denticules | Ziphodonty | Denticules density (number of denticle/5 mm) | Maxillary tooth count (absolute) | Maxillary tooth count (estimated) | Dentary tooth count (absolute) | Dentary tooth count (estimated) | Specimen description | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Metriorhynchinae | Rhacheosaurini | Cricosaurus suevicus (Fraas, 1901, 1902, SMNS 9808) | Upper Kimmeridgian | Germany | Smooth | Yes, faint | No | / | / | 26 | 24 | Complete specimen in limestone | ||
| Cricosaurus albersdoerferi (Sachs et al., 2021, BMMS-BK 1-2) | Upper Kimmeridgian | Germany | Smooth | Yes, faint | No | / | / | 23 | 23+ | 22 | 22+ | Complete specimen in limestone | ||
|
Cricosaurus elegans (Wagner, 1852, BSPG AS I 504) |
Lower Tithonian | Germany | Smooth | Yes, faint | No | Skull in limestone | ||||||||
| Cricosaurus bambergensis (Sachs et al., 2019, NKMB-P-Watt14/274) | Upper Kimmeridgian | Germany | Smooth | Yes, faint | No | / | / | 23 | 23+ | 18+ | 18+ | Complete specimen in limestone | ||
| Cricosaurus rauhuti (Herrera, Aiglstorfer & Bronzati, 2021, SNSB-BSPG 1973 I 195) | Lower Tithonian | Germany | Well-spaced, low longitudinal ridges | Yes, at least unicarenate | No | / | / | / | / | / | / | Incomplete skull | ||
| Maledictosuchus nuyiviianan (Barrientos-Lara, Alvarado-Ortega & Fernández, 2018, IGM 4863) | Kimmeridgian | Mexico | Smooth labial side. Discontinuous low apicobasal ridges on the lingual surface | Yes | No | / | / | 17 | 26? | / | / | Incomplete skull | ||
| ‘Cricosaurus’ saltillensis (Buchy, Young & Andrade, 2013, MUDE CPC 487) | Lower Tithonian | Mexico | Faint apicobasally aligned subparallel ridges |
Yes, faint | No | / | / | 12 | 17 | 15 | ~15? | Disarticulated skull | ||
|
Metriorhynchus palpebrosus (Phillips, 1871; Grange & Benton, 1996, (OUMNH J.29823) |
Lower Tithonian | United Kingdom | ? | ? | ? | ? | ? | 25 (OUMNH J.29823)-27 | / | 14 | 14+ | Skull. No teeth remaining | ||
| Metriorhynchus geoffroyii (Metriorhynchus brevirostris) (Young et al., 2020a; MHNG V-2232) | Lower Kimmeridgian | France | ? | ? | ? | ? | ? | 14 | 20+? (half of the rostrum is easily missing) | / | / | Anterior half of the rostrum, no teeth remaining | ||
| Geosaurinae | Geosaurini | ‘Metriorhynchus’ cf hastifer (Chouquet cf ‘hastifer’, Lepage et al., 2008; Eudes-Deslongchamps, 1867–1869) | Kimmeridgian | France | Conspicuous apicobasal ridges | Yes | ? | ? | 20? | 20+? | / | / | complete skull | |
| Dakosaurus maximus (Young et al., 2012b, SMNS 8203) | Upper Kimmeridgian | Germany | Overall smooth | Yes, prominent | Yes | Macro | 16–18 | 13 | 12 | Incomplete skull | ||||
| Plesiosuchus manselii (Young et al., 2012a, NHMUK PV OR40103) | Upper Kimmeridgian | United Kingdom | Low relief apicobasal ridges | Yes, prominent | Yes | Micro | ? | 14 | 14 to 18 | 13 | Incomplete skull | |||
| Geosaurus giganteus (Young & Andrade, 2009, NHM R.1229, NHM 37020) | Lower Tithonian | Germany | Overall smooth | Yes, prominent | Yes | Micro | ? | 12 (NHM 37020) | 12+ | 7 (NHM 37020) | 7+ | NHM R.1229 : middle portion of the skull and mandible, deformed. NHM 37020 : skull and mandible in limestone. | ||
| Geosaurus grandis (Young et al., 2012a, BSPG AS-VI-1) | Lower Tithonian | Germany | Smooth | Yes, prominent | Yes | Micro | 28,1 | 14 | ||||||
| Torvoneustes carpenteri (Grange & Benton, 1996, BRSMG Ce17365) | Upper Kimmeridgian | United Kingdom | Conspicuous apicobasal ridges | Yes, prominent | Yes | Micro | ? | 11 | 14 | / | / | Heavily crushed, incomplete skull | ||
| Torvoneustes coryphaeus (Young et al., 2013b, MJML K1863) | Lower Kimmeridgian | United Kingdom | Conspicuous apicobasal ridges | Yes, prominent | Yes | Micro | ? | 11 | 17-19 | / | / | Incomplete skull, half of the rostrum missing | ||
| Torvoneustes mexicanus (Barrientos-Lara et al., 2016, IGM 9026) | Kimmeridgian | Mexico | Conspicuous apicobasal ridges | Yes, prominent | Yes | Micro | 30 | 5 | 4 | Fragmentary rostrum | ||||
| MJSN BSY008-465 | Upper Kimmeridgian | Switzerland | Conspicuous apicobasal ridges | Yes, prominent | Yes | Micro | 30–40 | 15 | Up to 21 | 16 | Up to 17 | Disarticulated skull |
Note:
Gracilineustes acutus is excluded from the table due to the lack of information, the specimen was lost during WW2. The same goes for Rhacheosaurus gracilis NHMUK PV R 3948 for whom the teeth or alveoli are indistinguishable, while Rhacheosaurus cf gracilis LF 2426 skull is not entirely preserved. Therein the distinction between “true ziphodont” and “false ziphodont” condition as defined by Young et al. (2010) is not specified. The estimated tooth count is from the referred articles; the denticle density for D. maximus and Geo. grandis from Andrade et al. (2010) and for To. mexicanus from Barrientos-Lara et al. (2016).