Whaitsiidae, Haughton, 1918

Huttenlocker, Adam, 2009, An investigation into the cladistic relationships and monophyly of therocephalian therapsids (Amniota: Synapsida), Zoological Journal of the Linnean Society 157 (4), pp. 865-891 : 890

Whaitsiidae , including Viatkosuchus

(nine characters)

12. Suborbital bar deep (1). (Conv. in Lycosuchus .)

18. Postorbital bar moderately well-built (0). (Interpreted as a reversal to the primitive therocephalian condition.)

23. Parietal (= pineal) opening in adults absent/ extremely reduced (1). (Conv. in Dvinia , Euchambersia and derived baurioids.)

38. Portion of vomer separating the choanae bears specialized transverse processes just behind the contact with the premaxilla overlapping vomerial processes of the crista choanalis (2).

40. Vomers completely fused (2). (From Rubidge & Kitching, 2003.; conv. in cynodonts, Ericiolacerta and Bauria ; polymorphic in Theriognathus , with some specimens only partially fused.)

65. Dentary angle, lateral to the reflected lamina. is moderate/sharp (1). [Interpreted as a reversal to the primitive eutheriodont condition (shared with cynodonts, lycosuchids, scylacosaurids and akidnognathids, but not ‘hofmeyriids’ or most baurioids); conv. in Bauria ; Theriognathus has been coded both ‘0’ and ‘1’ for this character. This variation may be within the genus or even within a single species (i.e. sexual dimorphism; see Brink, 1980).]

67. Coronoid process dorsal extent in adults terminates below middle of orbit (0). (From Sidor, 2003; interpreted as primitive reversal; conv. in Ictidostoma and derived baurioids.)

76. Upper incisors bear longitudinal grooves (1). (From Hopson & Barghusen, 1986; conv. in Mirotenthes and Ictidosuchus ; however, this character may be more widespread within Eutherocephalia as suggested by Hopson & Barghusen, 1986.)

92. Trigeminal nerve exits via a foramen between the pro-otic and epipterygoid (1).