Eopteranodon
Encyclopedia
Eopteranodon is a genus
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 azhdarchoid
Azhdarchoidea
Azhdarchoidea is a group of pterosaurs within the suborder Pterodactyloidea.-Classification:Listing of families and genera after Unwin 2006 except where specified.* Superfamily Azhdarchoidea** Genus "Aurorazhdarcho"** Family Chaoyangopteridae...

 pterodactyloid pterosaur
Pterosaur
Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...

 from the Aptian
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...

-age Lower Cretaceous Yixian Formation
Yixian Formation
The Yixian Formation is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans 11 million years during the early Cretaceous period...

 of Beipaio City
Beipiao
Beipiao is a city in Chaoyang prefecture, Liaoning province, in Northeast China. It has a population of 202,807. The main industry in the area is coal mining. With vertical shafts of almost 1000m, these are some of the deepest coal mines in China. The coal produced is used for coking...

, Liaoning
Liaoning
' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...

, China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

.

The genus was in 2005 named by Lü Junchang and Xang Xingliao. 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...

 is Eopteranodon lii.

It is based on the type specimen or 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...

 BPV-078, an incomplete skeleton and skull. Its skull, including a large crest, was toothless and similar to that of Pteranodon. The skull lacks the point of the snout but it was in life less than 200 millimeters long (7.9 inches), and the animal had a wingspan
Wingspan
The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...

 of about 1.1 meters (3.6 feet). A second specimen, D2526, described in 2006, had a larger wingspan. Despite its similarities to Pteranodon, Eopteranodon was not placed into a family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 by its describers, who put it into the clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

 Pteranodontia as incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...

(uncertain position). Shortly thereafter, a phylogenetic
Phylogenetics
In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...

 study of all known Yixian pterosaurs by the same scientists found it to be close to the azhdarchoids, noted for the crested genera Tapejara and Tupuxuara
Tupuxuara
Tupuxuara is a genus of large, crested, toothless pterodactyloid pterosaur.The genus was in 1988 named and described by Alexander Kellner and Diogenes de Almeida Campos. The type species is Tupuxuara longicristatus. The genus name refers to a familiar spirit from the mythology of the Tupi...

, and the giant, long-necked Quetzalcoatlus
Quetzalcoatlus
Quetzalcoatlus was a pterodactyloid pterosaur known from the Late Cretaceous of North America , and one of the largest known flying animals of all time. It was a member of the Azhdarchidae, a family of advanced toothless pterosaurs with unusually long, stiffened necks...

. A further analysis of other recently discovered forms, in 2006 still considered basal to (having split off earlier than) azhdarchoids, helped the original authors, along with David Unwin, to place these species together with Eopteranodon in a new clade Chaoyangopteridae
Chaoyangopteridae
The Chaoyangopteridae are a family of pterosaurs within the Azhdarchoidea.The clade Chaoyangopteridae was first defined in 2008 by Lü Junchang and David Unwin as: "Chaoyangopterus, Shenzhoupterus, their most recent common ancestor and all taxa more closely related to this clade than to Tapejara,...

, the possible sister group of the Azhdarchidae
Azhdarchidae
Azhdarchidae is a family of pterosaurs known primarily from the late Cretaceous Period, though an isolated vertebrae apparently from an azhdarchid is known from the early Cretaceous as well...

.

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