Figure 2.

Composite phylogeny of therian mammals illustrating the occurrence of dental zalambdodonty within Theria. The topology is based on recent studies including [11–13,15,19,20,68–72]. Taxa that include at least one fully zalambdodont member are indicated by red branches. Extinct taxa are indicated by a dagger. Images (from top to bottom) are: the tenrecoid Tenrec ecaudatus (J. F. Eisenberg; AMS Image Library); an unidentified chrysochlorid Cryptochloris sp. (Wikimedia Commons image; Killer18); the apternodontid Apternodus baladontus (frontispiece [17]: p. 2); the solenodontid Solenodon paradoxus (J. Nuñez-Miño; www.thelastsurvivors.org); the necrolestid Necrolestes patagonensis (N. P. Archer); the yalkaparidontian Yalkaparidon coheni (D. Dunphy); the notoryctid Notoryctes typhlops (M. Gillam). The phylogeny was created using the phylogenetic drawing tool MrEnt 2.0 [73].