Kosmodraco

Kosmodraco is a genus of large bodied choristodere from the Paleocene of North America. Originally described as a species of the closely related Simoedosaurus, it was found to represent a distinct genus in 2022. Multiple fossil skulls show a relatively short and robust snout and a skull that is considerably wider behind the eyes. Two species are currently recognized, K. dakotensis and K. magnicornis.

==History and naming== The first specimen now known to belong to Kosmodraco was discovered in 1964 and 1968 in the Polecat Bench Formation (Wyoming). These two skulls, alongside others from Montana's Bear Creek, were reported on briefly by Sigogneau-Russell and Donald in 1978, who regarded them as evidence for the presence of the Eurasian genus Simoedosaurus in North America. However, at the time, these four specimens, although thought to be diagnostic at a genus level, were still unprepared and not assigned to a species. They were subsequently stored in the collection of the Princeton University. It wasn't until a fifth specimen from North Dakota was prepared that the North American remains were named, with Bruce R. Erickson creating the new species Simoedosaurus dakotensis in 1987 and assigning the Princeton material and two additional specimens to it. Erickson, however, did realize there were differences in the specimens, noting that the North Dakota specimen was not just older (mid Tiffanian) than the Princeton fossils (late Tiffanian to Clarkforkian) but also larger, which he initially attributed to differences between growth stages. Later, in 2022, Chase Doran Brownstein reexamined the American Simoedosaurus material, finding that it differed enough to be described as its own genus. Brownstein further considered that the two best preserved Princeton specimens, YPM VPPU 19168 and YPM VPPU 18724, weren't juveniles but should instead be considered a second species. Subsequently, the genus Kosmodraco was erected with K. dakotensis as the type species and a second species in the form of K. magnicornis.