Cimolopterygidae

Cimolopteryx (meaning "Cretaceous wing") is a prehistoric bird genus from the Late Cretaceous Period. It is currently thought to contain only a single species, Cimolopteryx rara. The only specimen confidently attributed to C. rara was found in the Lance Formation of Wyoming, dating to the end of the Maastrichtian age, which ended about million years ago. The dubious species "Cimolopteryx" maxima has been described from both the Lance Formation and the Hell Creek Formation of Montana. The humeral end of a left coracoid from the Frenchman Formation of southern Saskatchewan has also been attribut

Ceramornis is a genus of ornithuran dinosaurs from the Late Cretaceous. It lived shortly before the Cretaceous–Paleogene extinction event in the Maastrichtian, some Its remains were found in the Lull 2 location, a Lance Formation site in Niobrara County, Wyoming. A single species is known, Ceramornis major, and even that only from a proximal piece of coracoid. This is specimen UCMP V53957, which was collected by a University of California team in 1958. thumb|left|Size (lower middle right) compared to contemporary birds, pterosaurs, and a human