Changmiania

Changmiania is a genus of basal ornithopod dinosaur that inhabited what is now China during the Early Cretaceous period. The genus is known from a single species, Changmiania liaoningensis, represented by two remarkably complete and articulated skeletons. These fossils were discovered in the Lujiatun Beds of the Yixian Formation and date back to the Barremian age, approximately 123.2 million years ago. The genus name, derived from the Chinese "changmian" meaning "eternal sleep," reflects the life-like posture of the fossilized individuals, which suggests they may have been buried alive, possibly in their own burrows due to a volcanic eruption.

Discovery and Naming

The holotype specimen, PMOL AD00114, and a referred specimen, PMOL LFV022, were found by local farmers and later prepared at the Paleontological Museum of Liaoning. The fossils showed no signs of tampering by fossil thieves. In 2020, Yang Yuqing and colleagues formally named and described Changmiania liaoningensis. The specific name honors the discovery location in Liaoning Province.

Description and Paleobiology

Changmiania possessed several distinguishing anatomical traits, including autapomorphies such as elongated frontal bones, a straight and elongated front branch of the squamosal bone, and a distinctive boss on the upper rear corner of the squamosal. Its lower jaw had a sinuous profile, and the neural spines of its sacral vertebrae were fused into a continuous plate. A notable characteristic was its very short neck, featuring only six vertebrae, unlike the usual nine found in other ornithischians. Anatomical features like its short neck, short forelimbs and hands, and enlarged shoulder bones are interpreted as adaptations for burrowing, a behavior inferred from the fossil preservation and comparison with other small ornithischians like Oryctodromeus.