''Bennettazhia'' is a genus of tapejaromorph

pterosaur Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...

from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

period of what is now the Hudspeth Formation of the state of

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

in the United States. Although originally identified as a species of the pteranodontoid pterosaur ''

Pteranodon ''Pteranodon'' (); from Ancient Greek (''pteron'', "wing") and (''anodon'', "toothless") is a genus of pterosaur that included some of the largest known flying reptiles, with ''P. longiceps'' having a wingspan of . They lived during the late Cr ...

'', ''Bennettazhia'' is now thought to have been a different animal. The type and only species is ''B. oregonensis''.

Discovery and history

In 1928, Charles Gilmore named a new species of ''

'': ''P. oregonensis''. A

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

(

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

MPUC V.126713), two fused dorsal vertebrae and the broken-off end of some joint bone had been unearthed from the

Lower Cretaceous Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eight ...

(

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 113.0 ± 1.0 Ma to 100.5 ± 0.9 M ...

stage) beds of the Hudspeth Formation in

Wheeler County Wheeler County is the name of several counties in the United States: * Wheeler County, Georgia * Wheeler County, Nebraska * Wheeler County, Oregon * Wheeler County, Texas Wheeler County is a county located in the U.S. state of Texas. As of t ...

, in the state of

, United States, to which the

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

refers. Gilmore noted similarities to ''

Nyctosaurus ''Nyctosaurus'' (meaning "night lizard" or "bat lizard") is a genus of nyctosaurid pterosaur from the Late Cretaceous period of what is now the Niobrara Formation of the mid-western United States, which, during the time ''Nyctosaurus'' was al ...

'' 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 Lev may refer to: Common uses * Bulgarian lev, the currency of Bulgaria *an abbreviation for Leviticus, the third book of the Hebrew Bible and the Torah People and fictional characters * Lev (given name) *Lev (surname) Places *Lev, Azerbaijan, ...

therefore in 1991 named a new azhdarchid genus: ''Bennettazhia''. The genus name honors Bennett and combines his name with

Persian Persian may refer to: * People and things from Iran, historically called ''Persia'' in the English language ** Persians, the majority ethnic group in Iran, not to be conflated with the Iranic peoples ** Persian language, an Iranian language of the ...

''azhdarha'', "dragon", a reference to ''

Azhdarcho ''Azhdarcho'' is a genus of azhdarchid pterosaur from the late Cretaceous Period of the Bissekty Formation (middle Turonian stage, about 92 million years ago) of Uzbekistan, as well as the Zhirkindek Formation of Kazakhstan. It is known from ...

'', the

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...

of the Azhdarchidae. Bennett himself in 1994 changed his opinion and stated that it belonged to the

Dsungaripteridae Dsungaripteridae is a group of pterosaurs within the suborder Pterodactyloidea. They were robust pterosaurs with good terrestrial abilities and flight honed for inland settings. Classification In 1964 Young created a family to place the recentl ...

. Wellnhofer (1991), Peters (1997), Kellner (2003) and Unwin (2003) left it as belonging to the

Pterodactyloidea Pterodactyloidea (derived from the Greek words ''πτερόν'' (''pterón'', for usual ''ptéryx'') "wing", and ''δάκτυλος'' (''dáktylos'') "finger" meaning "winged finger", "wing-finger" or "finger-wing") is one of the two traditional ...

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

''.

Description

In 2007, American biologist Michael Habib revealed the result of a study by CAT-scan of the type specimen of ''Bennettazhia''. The humerus, 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

trabecula A trabecula (plural trabeculae, from Latin for "small beam") is a small, often microscopic, tissue element in the form of a small beam, strut or rod that supports or anchors a framework of parts within a body or organ. A trabecula generally ha ...

e, 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 ''Bennettazhia'' was a member of the

Azhdarchoidea Azhdarchoidea (or azhdarchoids) is a group of pterosaurs within the suborder Pterodactyloidea, more specifically within the group Ornithocheiroidea. Pterosaurs belonging to this group lived throughout the Early and Late Cretaceous periods, with ...

, a more encompassing group than the Azhdarchidae.

Classification

The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

below follows a 2014

phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

by Brian Andres and colleagues. In the analysis, they placed ''Bennettazhia'' within the clade Tapejaromorpha, as the

basalmost In phylogenetics, basal is the direction of the ''base'' (or root) of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to th ...

member.

References

*Gilmore C. W. (1928), "A new Pterosaurian reptile from the marine Cretaceous of Oregon", ''Proc. U. S. Nat. Mus.'' 73, art. 24, 1–5 *Bennett S. C. 1989, "Pathologies of the large pterodactyloid pterosaurs ''Ornithocheirus'' and ''Pteranodon''", ''Journal of Vertebrate Paleontology'', 9: 13A *Nesov, L. A. (1991), "Gigantskiye lyetayushchiye yashchyeryi semyeistva Azhdarchidae. I. Morfologiya, sistematika", ''Vestnik Leningradskogo Universiteta'', Seriya. 7; Geologiya, Geografiya (2), 14–23 *Bennett S. C. (1994), "Taxonomy and systematics of the Late Cretaceous pterosaur ''Pteranodon'' (Pterosauria, Pterodactyloidea)", ''Occ. Pap. Nat. Hist. Mus. Univ. Kansas'' 169 *Michael Habib (2007), "Structural characteristics of the humerus of ''Bennettazhia oregonensis'' and their implications for specimen diagnosis and azhdarchoid biomechanics", p. 16 in: ''Flugsaurier: The Wellnhofer pterosaur meeting'', Bavarian State Collection for Palaeontology, Munich 2007, bstract

External links

The Pterosaur Database (pdf)
{{Portal bar, Paleontology, Cretaceous, United States Early Cretaceous pterosaurs of North America Tapejaromorphs Early Cretaceous reptiles of North America Fossil taxa described in 1991 Fossil taxa described in 1928

Discovery and history

Description

Classification

See also

References

External links