''Mengciusornis'' is an extinct genus of basal

ornithuromorph Euornithes (from Greek ' meaning "true birds") is a natural group which includes the most recent common ancestor of all avialans closer to modern birds than to the enantiornithines. This group was defined in the ''PhyloCode'' by Juan Benito and ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s from the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

of China. It contains one species, ''M. dentatus'', remains of which have been found in the

Jiufotang Formation The Jiufotang Formation () is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms (see Jehol Biota). It is a member of the Jehol group. T ...

. Together with the closely related ''

Schizooura ''Schizooura'' is a genus under the classification of basal ornithuromorph dinosaurs, which are dinosaurs that are relatives of modern birds. This feathery creature was from the Early Cretaceous period (125.5 million years ago) in modern-day wes ...

'' it makes up the family

Schizoouridae Schizoouridae is an extinct family of euornithean theropods that lived in what is now China during the Early Cretaceous. It was named in 2019 by Wang and colleagues, and contains all taxa more closely related to '' Mengciusornis dentatus'' and '' ...

Description

''Mengciusornis'' is known from a single specimen, IVPP V26275, a well-preserved skeleton with remains of feathers. Unlike its sister genus ''Schizooura'', which was toothless, ''Mengciusornis'' possessed large, curved teeth on its

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals h ...

e, similar to those of the distantly related ''

Longipteryx ''Longipteryx'' is a genus of prehistoric bird which lived during the Early Cretaceous (Aptian stage, 120.3 million years ago). It contains a single species, ''Longipteryx chaoyangensis''. Its remains have been recovered from the Jiufotang Forma ...

''.

Etymology

The generic name honours the Chinese philosopher

Mencius Mencius (孟子, ''Mèngzǐ'', ; ) was a Chinese Confucian philosopher, often described as the Second Sage () to reflect his traditional esteem relative to Confucius himself. He was part of Confucius's fourth generation of disciples, inheriting ...

, while the

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

is Latin for "toothed".

References

Euornithes Bird genera Aptian birds Jiufotang Formation Fossil taxa described in 2019 Taxa named by Zhou Zhonghe Birds of Asia {{Paleo-bird-stub