Bennettazhia
Encyclopedia
Bennettazhia is a genus of pterosaur
(flying reptile).
In 1928 Charles Gilmore named a new species of Pteranodon
: P. oregonensis. A humerus
(holotype
MPUC V.126713), two fused dorsal vertebrae and the broken-off end of some joint bone had been unearthed from the Lower Cretaceous (Albian
) beds of the Hudspeth Formation in Wheeler County
, in the state of Oregon
, USA, to which the specific epithet refers. Gilmore noted similarities to Nyctosaurus
though the specimens were larger.
In 1989 S. Christopher Bennett concluded that the remains might be those of a member of the Azhdarchidae
instead of a pteranodontid
. Russian paleontologist Lev Nesov therefore in 1991 named a new azhdarchid genus: Bennettazhia. The genus name honours Bennett and combines his name with Uzbek
azh, "dragon", a reference to Azhdarcho
, the type genus
of the Azhdarchidae. Bennett himself in 1994 changed his opinion and stated that it belonged to the Dsungaripteridae
. Wellnhofer (1991), Peters (1997), Kellner (2003) and Unwin (2003) left it as belonging to the Pterodactyloidea
incertae sedis
.
In 2007 American biologist Michael Habib revealed the result of a study by CAT-scan of the type specimen. The humerus, 183 millimetres long, is uncrushed, which is uncommon for a pterosaur fossil and therefore offered a rare opportunity to investigate the bone structure. Apart from the thin bone wall, the humerus was filled with a spongy tissue consisting of trabeculae, very thin bone layers and struts, forming a light yet strong construction. Habib inferred that such strength would have allowed even very large pterosaurs to launch themselves from the ground using their forelimbs. The same investigation made a better classification possible. The humerus has an elongated deltopectoral crest that is unwarped. Both dsungaripterids and azhdarchoids show this feature, but only the latter group is typified by such a very thin outer bone wall. Habib concluded that Bennetazhia was a member of the Azhdarchoidea
, a more encompassing group than the Azhdarchidae.
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...
(flying reptile).
In 1928 Charles Gilmore named a new species of Pteranodon
Pteranodon
Pteranodon , from the Late Cretaceous geological period of North America in present day Kansas, Alabama, Nebraska, Wyoming, and South Dakota, was one of the largest pterosaur genera and had a maximum wingspan of over...
: P. oregonensis. A humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
(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...
MPUC V.126713), two fused dorsal vertebrae and the broken-off end of some joint bone had been unearthed from the Lower Cretaceous (Albian
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...
) beds of the Hudspeth Formation in Wheeler County
Wheeler County, Oregon
As of the census of 2000, there were 1,547 people, 653 households, and 444 families residing in the county. The population density was 1 people per square mile . There were 842 housing units at an average density of 0 per square mile...
, in the state of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, USA, to which the specific epithet refers. Gilmore noted similarities to Nyctosaurus
Nyctosaurus
Nyctosaurus is a genus of pterodactyloid pterosaur, the remains of which have been found in the Niobrara Formation of the mid-western United States, which, during the late Cretaceous Period, was covered in an extensive shallow sea. The genus Nyctosaurus has had numerous species referred to it,...
though the specimens were larger.
In 1989 S. Christopher Bennett concluded that the remains might be those of a member 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...
instead of a pteranodontid
Pteranodontidae
The Pteranodontidae are a family of large pterosaurs of the Cretaceous Period of North America.The family was named in 1876 by Othniel Charles Marsh....
. Russian paleontologist Lev Nesov therefore in 1991 named a new azhdarchid genus: Bennettazhia. The genus name honours Bennett and combines his name with Uzbek
Uzbek language
Uzbek is a Turkic language and the official language of Uzbekistan. It has about 25.5 million native speakers, and it is spoken by the Uzbeks in Uzbekistan and elsewhere in Central Asia...
azh, "dragon", a reference to Azhdarcho
Azhdarcho
Azhdarcho is a genus of pterodactyloid pterosaur from the late Cretaceous Period of the Bissekty Formation of Uzbekistan. It is known from fragmentary remains including the distinctive, elongated neck vertebrae that characterizes members of the family Azhdarchidae, which also includes such giant...
, the type genus
Type genus
In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...
of the Azhdarchidae. Bennett himself in 1994 changed his opinion and stated that it belonged to the Dsungaripteridae
Dsungaripteridae
Dsungaripteridae is a group of pterosaurs within the suborder Pterodactyloidea....
. Wellnhofer (1991), Peters (1997), Kellner (2003) and Unwin (2003) left it as belonging to the 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 2007 American biologist Michael Habib revealed the result of a study by CAT-scan of the type specimen. The humerus, 183 millimetres long, is uncrushed, which is uncommon for a pterosaur fossil and therefore offered a rare opportunity to investigate the bone structure. Apart from the thin bone wall, the humerus was filled with a spongy tissue consisting of trabeculae, very thin bone layers and struts, forming a light yet strong construction. Habib inferred that such strength would have allowed even very large pterosaurs to launch themselves from the ground using their forelimbs. The same investigation made a better classification possible. The humerus has an elongated deltopectoral crest that is unwarped. Both dsungaripterids and azhdarchoids show this feature, but only the latter group is typified by such a very thin outer bone wall. Habib concluded that Bennetazhia was a member of the Azhdarchoidea
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...
, a more encompassing group than the Azhdarchidae.