''Zosuchus'' ("Zos

anyon In physics, an anyon is a type of quasiparticle so far observed only in two-dimensional physical system, systems. In three-dimensional systems, only two kinds of elementary particles are seen: fermions and bosons. Anyons have statistical proper ...

crocodile") is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of basal,

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

crocodyliform Crocodyliformes is a clade of Crurotarsi, crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the ...

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 The Djadochta formation (sometimes transcribed and also known as Djadokhta, Djadokata, or Dzhadokhtskaya) is a highly fossiliferous geological formation in Central Asia, Gobi Desert, dating from the Late Cretaceous period, about 75 million ...

) in the

Gobi Desert The Gobi Desert (, , ; ) is a large, cold desert and grassland region in North China and southern Mongolia. It is the sixth-largest desert in the world. The name of the desert comes from the Mongolian word ''gobi'', used to refer to all of th ...

Mongolia Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south and southeast. It covers an area of , with a population of 3.5 million, making it the world's List of countries and dependencies by po ...

by expeditions organized by the

American Museum of Natural History The American Museum of Natural History (AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. Located in Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 21 interconn ...

, 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.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.

Sources

* Pol, D. & Norell, M. A., (2004). "A new crocodyliform from Zos Canyon, Mongolia". ''American Museum Novitates'' 3445: 1-36. Crocodyliformes Late Cretaceous crocodylomorphs of Asia Terrestrial crocodylomorphs Fossils of Mongolia Prehistoric pseudosuchian genera {{paleo-archosaur-stub