Eosipterus
Encyclopedia
Eosipterus is an extinct genus
of pterosaur
from the Early Cretaceous
of Liaoning
, China
.
The genus was named in 1997 by Ji Shu'an and Ji Qiang. The type species
is Eosipterus yangi. The genus name is derived from Greek eos, "dawn" and Greek pteron, "wing" with a Latin ending; and a grammar error: normally the combination would have resulted in "eopterus". The "dawn" element refers to its age but also to China being "in the east". The specific name honours paleontologist Yang Daihuan.
The genus is based on holotype
GMV2117, found near Jinggangshan in western Liaoning Province, in the Yixian Formation
. It was the first pterosaur discovered in that region. It consists of a partial crushed skeleton of a subadult individual on a slab, lacking skull and neck. Most vertebrae have been severely damaged and even their number cannot be determined. The authors state that eighteen detached belly ribs are present in the matrix.
The wings are robust and elongated. The wing finger has the standard four phalanges, a difference from the possibly related Beipiaopterus
which has lost the fourth phalanx. Total wingspan was about 1,2 metres. The pelvis is not well preserved. The femur has a length of six centimetres; the tibia of 96 millimetres. The fibula is strongly reduced. The foot claws are slightly curved; the fifth toe has been reduced to a single claw.
The authors placed Eosipterus in a general Pterodactyloidea
incertae sedis
; in 1999 a placement within Pterodactylidae was suggested and even a synonymy with Pterodactylus within a hypothesis that the lower Yixian Formation dated from the late Jurassic
. A cladistic study in 2006 found that it was a member of the Ctenochasmatidae
— David Unwin thought it more precisely belonged to the Ctenochasmatinae — but a later study showed that it was basal to the Germanodactylidae
.
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 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 Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
of 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
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
.
The genus was named in 1997 by Ji Shu'an and Ji Qiang. 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 Eosipterus yangi. The genus name is derived from Greek eos, "dawn" and Greek pteron, "wing" with a Latin ending; and a grammar error: normally the combination would have resulted in "eopterus". The "dawn" element refers to its age but also to China being "in the east". The specific name honours paleontologist Yang Daihuan.
The genus is based on 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...
GMV2117, found near Jinggangshan in western Liaoning Province, in the 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...
. It was the first pterosaur discovered in that region. It consists of a partial crushed skeleton of a subadult individual on a slab, lacking skull and neck. Most vertebrae have been severely damaged and even their number cannot be determined. The authors state that eighteen detached belly ribs are present in the matrix.
The wings are robust and elongated. The wing finger has the standard four phalanges, a difference from the possibly related Beipiaopterus
Beipiaopterus
Beipiaopterus is a genus of ctenochasmatid pterosaur from the Lower Cretaceous Yixian Formation in the People's Republic of China....
which has lost the fourth phalanx. Total wingspan was about 1,2 metres. The pelvis is not well preserved. The femur has a length of six centimetres; the tibia of 96 millimetres. The fibula is strongly reduced. The foot claws are slightly curved; the fifth toe has been reduced to a single claw.
The authors placed Eosipterus in a general Pterodactyloidea
Pterodactyloidea
Pterodactyloidea forms one of the two suborders of pterosaurs , and contains the most derived members of this group of flying reptiles...
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...
; in 1999 a placement within Pterodactylidae was suggested and even a synonymy with Pterodactylus within a hypothesis that the lower Yixian Formation dated from the late Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
. A cladistic study in 2006 found that it was a member of the Ctenochasmatidae
Ctenochasmatidae
Ctenochasmatidae is a group of pterosaurs within the suborder Pterodactyloidea.-Classification:Listing of subfamilies and genera after Unwin 2006 unless otherwise noted.* Family Ctenochasmatidae** Elanodactylus** Gegepterus...
— David Unwin thought it more precisely belonged to the Ctenochasmatinae — but a later study showed that it was basal to the Germanodactylidae
Germanodactylidae
Germanodactylidae is a group of pterosaurs within the suborder Pterodactyloidea. While its exact placement and content are controversial, recent studies have suggested it contains three genera: Germanodactylus, Normannognathus and Tendaguripterus...
.
External links
- Eosipterus in The Pterosauria