Skull, mandible, and hyoid of Shinisaurus crocodilurus Ahl (Squamata, Anguimorpha)

Abstract

Shinisaurus crocodilurus Ahl is an endangered lizard of uncertain phylogenetic affinities with a very restricted geographic distribution within southern China and northern Vietnam. Available cranial descriptions are brief and based on incomplete or immature specimens. Consequently, the cranial structure of this important species remains poorly documented. This paper provides a detailed redescription based on several well‐preserved adult and subadult skeletons. Description of individual bones corrects errors in previous studies. Comparisons with extant and fossil anguimorphs, especially Xenosaurus, allow a new diagnosis of cranial autapomorphies for Shinisaurus. The significance of Shinisaurus for anguimorph interrelationships is discussed briefly. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 141, 399–434.

Re-assessment of varanid evolution based on new data from Saniwa ensidens Leidy, 1870 (Squamata, Reptilia)

“…These are 58 (0) Varanidae is typically considered to include extant Varanus, Lanthanotus, and all descendants of their last common ancestor (Pregill et al, 1986;Estes et al, 1988;Pianka, 1995;Lee, 1998;Bernstein, 1999;Conrad, 2004Conrad, , 2008. The current analysis recovers five unambiguous synapomorphies for Varanidae including Aiolosaurus.…”

Osteology of Gobiderma pulchrum (Monstersauria, Lepidosauria, Reptilia)

“…Cranial anatomical terminology used herein follows that of Oelrich (1956) and some more recent papers that offer modifications to that terminology (Maisano, 2001c;Conrad, 2004;Bever et al, 2005a). Postcranial anatomical terminology primarily follows the usages of Romer (1956), Rieppel (1980b), Estes et al (1988), and Maisano (2001c).…”

“…The cranial portion includes the part of the skull posterior to that point. Modified from Montero and Gans (1999) and as described by Conrad (2004). regions.…”

The braincases of two glyptosaurines (anguidae, Squamata) and anguid phylogeny

“…This compound structure is referred to as the otooccipital (following recent usage, e.g., Maisano, 2001;Maisano et al, 2002;Conrad, 2004;Bever et al, 2005a;Maisano et al, 2006). The opisthotic portions of the otooccipitals in both specimens are generally less complete than the exoccipital portions.…”

“…The anterior and middle braincase floor of many squamates is thin relative to surrounding areas of the braincase. For example, the posterior part of the sphenoid and anterior part of the basioccipital are thin in Shinisaurus crocodilurus (Conrad, 2004;Bever et al, 2005a, b) and Heloderma suspectum (Bonine, 2005). Some anguids possess a similar thinning of the braincase floor in tandem with a dorsally projecting fossa on the ventral surface of the sphenoid and/or basioccipital (see, for example, coronal slices 550-577 in Maisano, 2006) (Criley, 1968;Rieppel, 1980;Good, 1987;Maisano, 2006;personal obs.).…”