Yandangornis
Encyclopedia
Yandangornis is a genus
of primitive bird
(or possibly non-avialan
theropod) from the Late Cretaceous
. It lived 85 million years ago in what is now China. The type species
, Y. longicaudus, was formally described by Cai and Zhou in 1999. The holotype
specimen is in the collection of the Zhejiang Museum of natural History, with accession number M1236. The fossil was discovered in 1986, near Linhai City in Zhejiang Province, China. It includes most of one complete skeleton.
The specimen is small, roughly the size of Archaeopteryx
, with a total length around 58.8 centimetres (1.9 ft). The head is 50 millimetres (2 in) long. It is preserved in a seated position and visible from the ventral aspect. It has a long tail, with traces of tail feathers preserved. It has no teeth and no enlarged 2nd toe claw.
Cai and Zhao noted some features of Yandangornis that are more primitive than Archaeopteryx
, and some, like toothlessness, that could be more derived.
Zhou and Zhang, 2007, reviewed the specimen and concluded that it lacks the diagnostic characters of birds, and that thus may to be a non-avian dinosaur.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of primitive bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
(or possibly non-avialan
Avialae
Avialae is a clade of dinosaurs containing their only living representatives, birds , and the most immediate extinct relatives of birds.-Competing definitions:...
theropod) from the Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
. It lived 85 million years ago in what is now China. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
, Y. longicaudus, was formally described by Cai and Zhou in 1999. The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
specimen is in the collection of the Zhejiang Museum of natural History, with accession number M1236. The fossil was discovered in 1986, near Linhai City in Zhejiang Province, China. It includes most of one complete skeleton.
The specimen is small, roughly the size of Archaeopteryx
Archaeopteryx
Archaeopteryx , sometimes referred to by its German name Urvogel , is a genus of theropod dinosaur that is closely related to birds. The name derives from the Ancient Greek meaning "ancient", and , meaning "feather" or "wing"...
, with a total length around 58.8 centimetres (1.9 ft). The head is 50 millimetres (2 in) long. It is preserved in a seated position and visible from the ventral aspect. It has a long tail, with traces of tail feathers preserved. It has no teeth and no enlarged 2nd toe claw.
Cai and Zhao noted some features of Yandangornis that are more primitive than Archaeopteryx
Archaeopteryx
Archaeopteryx , sometimes referred to by its German name Urvogel , is a genus of theropod dinosaur that is closely related to birds. The name derives from the Ancient Greek meaning "ancient", and , meaning "feather" or "wing"...
, and some, like toothlessness, that could be more derived.
Zhou and Zhang, 2007, reviewed the specimen and concluded that it lacks the diagnostic characters of birds, and that thus may to be a non-avian dinosaur.