Zosuchus

Zosuchus Temporal range: Late Cretaceous
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauria
Clade:	Pseudosuchia
Clade:	Crocodylomorpha
Clade:	Crocodyliformes
Clade:	Mesoeucrocodylia
Genus:	†Zosuchus Pol and Norell, 2004
Species
†Z. davidsonae Pol and Norell, 2004 (type)

Zosuchus ("Zos [Canyon] crocodile") is a genus of basal, Late Cretaceous crocodyliform from Mongolia.

The type species is Z. davidsoni, after preparator Amy Davidson. The name was amended to davidsonae in 2004.

Discovery

It was found in the Redbeds of Zos Canyon (Djadokhta Formation) in the Gobi Desert of Mongolia by expeditions organized by the American Museum of Natural History, and described by palaeontologists Diego Pol and Mark Norell in 2004.

Material of Z. davidsonae consists of five specimens:

• IGM 100/1305 (holotype): isolated skull and lower jaws
• IGM 100/1304
• IGM 100/1306
• IGM 100/1307
• IGM 100/1308

Morphology

This genus had a very short snout.

Systematics

Pol & Norell (2004) found Zosuchus davidsoni to be sister to Sichuanosuchus and Shantungosuchus, the three forming a basal clade of crocodyliforms based on the presence of a ventrally deflected posterior region of the mandibular rami. A 2018 cladistic analysis found Zosuchus, along with Sichuanosuchus, Shantungosuchus, and Shartegosuchidae, to form a basal mesoeucrocodyliform clade, Shartegosuchoidea.^[1]

Sources

1. Kathleen N. Dollman; James M. Clark; Mark A. Norell; Xu Xing; Jonah N. Choiniere (2018). "Convergent evolution of a eusuchian-type secondary palate within Shartegosuchidae". American Museum Novitates. 3901: 1–23. doi:10.1206/3901.1.

• Pol, D. & Norell, M. A., (2004). "A new crocodyliform from Zos Canyon, Mongolia". American Museum Novitates 3445: 1-36.