Yabeinosaurus tenuis, Endo & Shikama, 1942

Conrad, J. L., 2008, Phylogeny And Systematics Of Squamata (Reptilia) Based On Morphology, Bulletin of the American Museum of Natural History 2008 (310), pp. 1-182 : 111-112

Yabeinosaurus tenuis + Anguiformes

(figs. 55D, 56C)

DIAGNOSIS: Yabeinosaurus tenuis and anguiforms form a clade exclusive of all other squamates diagnosed by 26(0) absence of strong medial processes of the maxilla posterior to the premaxillary nasal process, 176(1) position of the posterior mylohyoid foramen posterior to the coronoid apex, and 185(1) presence of distinct subcoronoid and surangular processes of the dentary.

COMMENTS: Evans et al. (2005) recently redescribed Y. tenuis and inserted it into some recent phylogenetic data matrices. They found Y. tenuis to be a basal scleroglossan or as the immediate outgroup to crown-squamates (Evans et al., 2005). The current analysis produces a markedly different result, suggesting that Y. tenuis is a basal anguimorph, close to the crown group.