Sunosuchus junggarensis sp.nov. (Archosauria: Crocodyliformes) from the Upper Jurassic of Xinjiang, People's Republic of China

Abstract

A new species of Crocodyliformes, Sunosuchus junggarensis, is established on the basis of six individuals from the Upper Jurassic of the Junggar Basin, Xinjiang, northwest China. It differs from other species of Sunosuchus primarily in having a dorsoventrally depressed supraoccipital that, in occipital view, lacks a median crest; a frontal that is ridged anteriorly; a distinct depression distal to the foramen aereum on the dorsal surface of the quadrate; and an elongate, undivided maxillary depression. Cranial ontogenetic variation in S. junggarensis is discussed. Sunosuchus is probably a goniopholidid crocodyliform. It is distinguished from other genera of the Goniopholididae by a narrow and elongate snout, a small skull table, a partially ridged frontal, a pair of anteriorly located anterior palatal fenestrae, a lateroventrally -mediodorsally expanded retroarticular process, some enlarged pits on the frontal, and an elongate mandibular symphysis, with the splenial forming a small part of it. Sunosuchus, Eutretauranosuchus, and some species of Goniopholis may form a monophyletic group within the Mesoeucrocodylia.Resum6 : Une nouvelle espkce de Crocodyliformes, Sunosuchus junggarensis, est Ctablie et fondke sur six individus provenant de lithologies du Jurassique supkrieur, dans le bassin de Junggar, Xinjiang, le nord-ouest de la Chine. Elle se distingue des autres espkces de Sunosuchus, principalement par son supraoccipital dkprimk dans la region dorsoventrale, qui, en w e occipitale, est caractkrisk par l'absence d'une crkte mkdiane; un frontal muni d'un bourrelet antkrieur; une dkpression distale distincte au foramen aereum apparaissant sur la surface dorsale de 1'0s carrk; et une dkpression maxillaire indivise et allongke. Nous discutons de la variation ontogknique crlniale dans S. junggarensis. Sunosuchus est probablement un crocodyliforme goniopholidide. Il diff'ere des autres genres de GoniopholididCs par un museau Ctroit et allongC, une table crlnienne rkduite, un frontal partiellement renfle par un bourrelet, une paire de fenktres palatales antkrieures en position antkrieure, une apophyse rktroarticulaire ktendue dans les rkgions latkroventral-mkdiodorsal, de petits creux Cvasks sur le frontal et une symphyse mandibulaire allongte dont une petite portion est occupCe par le splknial. Sunosuchus, Eutretauranosuchus et quelques espkces de Goniopholis peuvent former un groupe monophylktique i l'intkrieur des Mesoeucrocodylia.[Traduit par la r&laction]

New material from a huge specimen of "Anteophthalmosuchus" cf. "escuchae" (Goniopholididae) from the Albian of Andorra (Teruel, Spain): Phylogenetic implications

“…Paravertebral, ventral, appendicular and nuchal dorsolateral osteoderms have been identified. The dermal armour is very similar to that of goniopholidids such as Goniopholis simus from the Berriasian of England and Germany, Anteophthalmosuchus hooleyi from the Valanginian of England, the unnamed Dollo's goniopholidid from the Barremian-Aptian of Belgium, Goniopholis baryglyphaeus from the Kimmeridgian of Portugal, and Sunosuchus junggarensis from the Late Jurassic of China (Wu et al, 1996;Salisbury and Frey, 2001;Schwarz, 2002;Salisbury and Naish, 2011).…”

“…In a few ventral osteoderms, smooth overlapping facets are observed along one margin of their outer surfaces (Fig. 5J-K); these osteoderms are from the region between the neck and trunk in other goniopholidids such as Sunosuchus (Wu et al, 1996).…”

“…4J-K) is very similar to the last cervical vertebra. It can be distinguished by its slightly longer diapophyses, which are dorsally placed with respect to the neural canal, or the parapophyses, which are less marked, dorsally placed and closer to the neurocentral suture (Mook, 1921;Wu et al, 1996;Nascimento and Zaher, 2010). In the first dorsal vertebra there is still a crest in the ventral region of the centrum, whereas in the other preserved dorsal vertebrae this crest does not exist.…”

“…There are other osteoderms similar in shape; these are from the limbs (Fig. 5M), but lack the ridge on the dorsal surface (Wu et al, 1996).…”

Morphology of the Late Cretaceous Crocodylomorph Shamosuchus djadochtaensis and a Discussion of Neosuchian Phylogeny as Related to the Origin of Eusuchia

“…14). Wu et al (1996aWu et al ( , 2001a, however, noted that a smooth depressed lobe of the squamosal may have a wider distribution and that it is ontogenetically variable in Sunosuchus junggarensis. Interestingly, Rugosuchus nonganensis has a morphology similar to Shamosuchus djadochtaensis, having the posterolateral region slightly sculpted, depressed, and separated by a weak ridge .…”