Eurazhdarcho

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Eurazhdarcho
Temporal range: Late Cretaceous, 69  Ma
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Eurazhdarcho.png
Preserved elements re-assembled as found in partial articulation
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Suborder: Pterodactyloidea
Family: Azhdarchidae
Subfamily: Quetzalcoatlinae
Genus: Eurazhdarcho
Vremir et al., 2013
Type species
Eurazhdarcho langendorfensis
Vremir et al., 2013

Eurazhdarcho is a genus of azhdarchid pterosaur from the Late Cretaceous period (Maastrichtian stage) of what is now the Transylvanian Basin of Romania. Its fossil remains dated back 69 million years ago. [1]

Contents

Discovery and naming

Metacarpal four Eurazhdarcho metacarpal.png
Metacarpal four

In 2009, Mátyás Vremir at Lancrăm near Sebeș-Glod in Transylvania at the SbG-B site uncovered the remains of a pterosaur. He donated these to the Erdélyi Múzeum, of the Societății Muzeului Ardelean (Transylvanian Museum Society). Subsequent excavations by Vremir discovered additional bones of the same individual animal and were added by him to the collection of the Babeș-Bolyai University. [1]

In 2013, Vremir, Alexander Wilhelm Armin Kellner, Darren Naish, and Gareth Dyke named and described the type species Eurazhdarcho langendorfensis. The generic name combines the name of Europe with that of the related form Azhdarcho . The specific name refers to Langendorf, the name of Lancrăm in the language of the German ethnic minority in Romania. The article appeared in the electronic journal PLoS ONE without an accompanying printed version; it nevertheless validly names the taxon under the new rules of the ICZN. [1]

The holotype, EME VP 312, was found in a layer of the Sebeș Formation dating from the upper Early Maastrichtian, about 69 million years old. It consists of a partial skeleton lacking the skull. It includes three neck vertebrae among which the almost complete third and the fourth; the third and fourth right metacarpal; the upper part of the first phalanx of the wing finger; the lower part of the second phalanx; a lower phalanx of one of the other fingers and a number of undetermined fragments. The Babeș-Bolyai University material is included within this enumeration and is not indicated by a separate inventory number. Generally the quality of the bones is poor with much of the outer cortex broken or eroded and internal structures present as (impressions of) natural molds. The fossils have not been completely flattened, preserving three-dimensionality, but compression has caused some distortion. The carcass had probably by flooding been deposed on its back in mud near a riverbank. Afterwards it was exposed to the air, weathering and being scavenged as proven by circular bite-marks inflicted by the conical teeth of some member of the Crocodyliformes. Later covered by a thin layer of dirt, it was damaged by beetles and termites. [1]

The authors noted that from the same Romanian layers the related giant form Hatzegopteryx is known; the known fossil material from both genera does not overlap. The authors considered an identity to be unlikely because the much smaller EME VP 312 seems to represent an adult individual. [1]

Description

Silhouette restoration showing the known remains in white Eurazhdarcho langendorfensis..png
Silhouette restoration showing the known remains in white
Life restoration Eurazhdarcho restoration.jpg
Life restoration

Eurazhdarcho is a medium-sized azhdarchid. The authors estimated its wingspan at 3 meters (9.8 ft), extrapolating from an estimated length for the fourth metacarpal of about 25 centimeters (9.8 in). [1]

The authors established some distinctive traits, all present in the cervical vertebrae. The third neck vertebra has three-quarters of the length of the fourth vertebra, whereas 60 percent would be normal with azhdarchids. The necks of the prezygapophyses, the front joint processes, are well-developed and elongated, obliquely pointing forwards and outwards under an angle of 30 degrees with the long axis of the vertebra. The preexapophysis, a secondary joint process on the side of the prezygapophysis, is well-developed with a forward pointing articulation facet and separated from a process, itself the remains of the diapophysis and possibly a neck rib, on the outer base of the prezygapophysis, by a deep trough on its underside. The pneumatic openings, the entrance holes for the air sacks, at the sides of the neural arch are small and placed in a low position. [1]

Phylogeny

Eurazhdarcho was by the authors assigned to the Azhdarchidae, based on the method of comparative anatomy; a cladistic analysis was not performed. [1] In 2018 however, Nicholas Longrich and colleagues included Eurazhdarcho in a large phylogenetic analysis of the Pterosauria, where it was recovered within the family Azhdarchidae. [2] Their cladogram is presented below:

Azhdarchidae

Montanazhdarcho

Azhdarcho

Phosphatodraco

Aralazhdarcho

Eurazhdarcho

aff. Quetzalcoatlus

Zhejiangopterus

Arambourgiania

Hatzegopteryx

Quetzalcoatlus

Paleobiology

Third cervical vertebra Eurazhdarcho vertebra.png
Third cervical vertebra

The area where Eurazhdarcho was found, in the Upper Cretaceous was localized on the Hațeg Island, part of the European Archipelago. The SbG-B site, though encompassing a surface of just 200 m³, has yielded several distinct animal species among which the turtle Kallokibotion bajazidi , the hadrosaur Telmatosaurus and a form referred to the titanosaur Magyarosaurus . This terrestrial fauna suggests that Eurazdarcho was not a coastal piscivore catching fish on the wing, affirming the "superstork" model for azhdarchids, in which they are terrestrial stalkers snatching small prey animals while walking on all fours. [1]

Map of azhdarchid sites with size distinction Azhdarchid map.png
Map of azhdarchid sites with size distinction

If Eurazhdarcho was indeed distinct from Hatzegopteryx, its discovery implies the presence of two azhdarchid forms in the Hațeg fauna, the one gigantic, the other medium-sized. This suggests a niche partitioning between them, although it is as yet unclear how this correlates with differences in prey preference and hunting techniques. This reflects a pattern seen in other Late Cretaceous faunae which also show a combination of a large azhdarchid species with a smaller one. The Javelina Formation from the Maastrichtian of Texas has brought forth the giant Quetzalcoatlus northropi but also a smaller Quetzalcoatlus sp. and the azhdarchoid represented by specimen TMM 42489-2. The Two Medicine Formation fauna from the Campanian of Montana includes the smaller Montanazhdarcho minor, with a wingspan of 2.5 meters (8 ft 2 in), but also fragments of larger forms with a span of 8 meters (26 ft). In the coeval Dinosaur Park Formation of Canada the smaller specimen RTMP 92.83 was discovered with a wingspan of 5 to 6 meters (16 to 20 ft) but also the large specimen PMA P.80.16.1367 indicating a wingspan of about 10 meters (33 ft) wide. [1] [ failed verification ]

See also

Related Research Articles

<i>Quetzalcoatlus</i> Genus of azhdarchid pterosaurs from the Late Cretaceous

Quetzalcoatlus is a genus of azhdarchid pterosaur known from the Late Cretaceous Maastrichtian age of North America. Its name comes from the Aztec feathered serpent god Quetzalcoatl. The type species is Q. northropi, named by Douglas Lawson in 1975. The genus also includes the smaller species Q. lawsoni, which was known for many years as an unnamed species, before being named by Brian Andres and Wann Langston Jr. (posthumously) in 2021. Q. northropi has gained fame as a candidate for the largest flying animal ever discovered.

<i>Magyarosaurus</i> Extinct genus of dinosaurs

Magyarosaurus is a genus of dwarf sauropod dinosaur from late Cretaceous Period in Romania. It is one of the smallest-known adult sauropods, measuring only 6 m (20 ft) in length and 750–1,000 kg (1,650–2,200 lb) in body mass. The type and only certain species is Magyarosaurus dacus. It has been found to be a close relative of Rapetosaurus in the family Saltasauridae in the sauropod clade Titanosauria in a 2005 study.

<span class="mw-page-title-main">Azhdarchidae</span> Family of large azhdarchoid pterosaurs

Azhdarchidae is a family of pterosaurs known primarily from the Late Cretaceous Period, though an isolated vertebra apparently from an azhdarchid is known from the Early Cretaceous as well. Azhdarchids are mainly known for including some of the largest flying animals discovered, but smaller cat-size members have also been found. Originally considered a sub-family of Pteranodontidae, Nesov (1984) named the Azhdarchinae to include the pterosaurs Azhdarcho, Quetzalcoatlus, and Titanopteryx. They were among the last known surviving members of the pterosaurs, and were a rather successful group with a worldwide distribution. Previously it was thought that by the end of the Cretaceous, most pterosaur families except for the Azhdarchidae disappeared from the fossil record, but recent studies indicate a wealth of pterosaurian fauna, including pteranodontids, nyctosaurids, tapejarids and several indeterminate forms. In several analyses, some taxa such as Navajodactylus, Bakonydraco and Montanazhdarcho were moved from Azhdarchidae to other clades.

<i>Arambourgiania</i> Genus of large azhdarchid pterosaur from the Late Cretaceous

Arambourgiania is an extinct genus of azhdarchid pterosaur from the Late Cretaceous period of Jordan, and possibly the United States. Arambourgiania was among the largest members of its family, the Azhdarchidae, and it is also one of the largest flying animals ever known. The incomplete left ulna of the "Sidi Chennane azhdarchid" from Morocco may have also belonged to Arambourgiania.

<span class="mw-page-title-main">Hațeg Island</span> Prehistoric island

Hațeg Island was a large offshore island in the Tethys Sea which existed during the Late Cretaceous period, probably from the Cenomanian to the Maastrichtian ages. It was situated in an area corresponding to the region around modern-day Hațeg, Hunedoara County, Romania. Maastrichtian fossils of small-sized dinosaurs have been found in the island's rocks. It was formed mainly by tectonic uplift during the early Alpine orogeny, caused by the collision of the African and Eurasian plates towards the end of the Cretaceous. There is no real present-day analog, but overall, the island of Hainan is perhaps closest as regards climate, geology and topography, though still not a particularly good match. The vegetation, for example, was of course entirely distinct from today, as was the fauna.

<i>Hatzegopteryx</i> Genus of large azhdarchid pterosaur from the Late Cretaceous

Hatzegopteryx is a genus of azhdarchid pterosaur found in the late Maastrichtian deposits of the Densuş Ciula Formation, an outcropping in Transylvania, Romania. It is known only from the type species, Hatzegopteryx thambema, named by Buffetaut et al. in 2002 based on parts of the skull and humerus. Additional specimens, including a neck vertebra, were later placed in the genus, representing a range of sizes. The largest of these remains indicate it was among the biggest pterosaurs, with an estimated wingspan of 10 to 12 metres.

<i>Montanazhdarcho</i> Genus of azhdarchoid pterosaur from the Late Cretaceous

Montanazhdarcho is a genus of azhdarchoid pterosaur from the Late Cretaceous period of what is now the state of Montana, United States. Montanazhdarcho is known from only one species, M. minor.

Eoazhdarcho is a genus of azhdarchoid pterodactyloid pterosaur named in 2005 by Chinese paleontologists Lü Junchang and Ji Qiang. The type and only known species is Eoazhdarcho liaoxiensis. The fossil was found in the Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China.

<i>Phosphatodraco</i> Late Cretaceous genus of pterosaur

Phosphatodraco is a genus of azhdarchid pterosaur that lived during the Late Cretaceous of what is now Morocco. In 2000, a pterosaur specimen consisting of five cervical (neck) vertebrae was discovered in the Ouled Abdoun Phosphatic Basin. The specimen was made the holotype of the new genus and species Phosphatodraco mauritanicus in 2003; the genus name means "dragon from the phosphates", and the specific name refers to the region of Mauretania. Phosphatodraco was the first Late Cretaceous pterosaur known from North Africa, and the second pterosaur genus described from Morocco. It is one of the only known azhdarchids preserving a relatively complete neck, and was one of the last known pterosaurs. Additional cervical vertebrae have since been assigned to the genus, and it has been suggested that fossils of the pterosaur Tethydraco represent wing elements of Phosphatodraco.

<i>Aralazhdarcho</i> Genus of azhdarchid pterosaur from the Late Cretaceous

Aralazhdarcho is a genus of azhdarchid pterosaur from the Santonian to the early Campanian stages of the Late Cretaceous period of Bostobe Svita in Kazakhstan. The type and only known species is Aralazhdarcho bostobensis.

Elanodactylus is a genus of ctenochasmatid pterodactyloid pterosaur from the Early Cretaceous period of what is now the Yixian Formation of Liaoning, China.

<i>Volgadraco</i> Genus of ornithocheiroid pterosaur from the Late Cretaceous

Volgadraco is a genus of pterodactyloid pterosaur from the Upper Cretaceous of European Russia. Volgadraco was originally classified as an azhdarchid. However, recent studies have concluded that it may belong to either the family Nyctosauridae, or the family Pteranodontidae.

<i>Alanqa</i> Genus of azhdarchid pterosaur from the Late Cretaceous

Alanqa is a genus of pterodactyloid pterosaur from the Late Cretaceous period of what is now the Kem Kem Beds of southeastern Morocco. The name Alanqa comes from the Arabic word العنقاءal-‘Anqā’, for a mythical bird of Arabian culture.

<i>Paludititan</i> Extinct genus of dinosaurs

Paludititan is a genus of titanosaurian sauropod dinosaur which lived in the area of present Romania during the Late Cretaceous. It existed in the island ecosystem known as Hațeg Island.

<i>Aerotitan</i> Genus of azhdarchid pterosaur from the Late Cretaceous

Aerotitan is a genus of large azhdarchid pterosaur known from the Late Cretaceous period of what is now the Allen Formation of the Neuquén Basin in northern Patagonia, Argentina.

<i>Mistralazhdarcho</i> Extinct genus of pterosaur

Mistralazhdarcho is a genus of azhdarchid pterosaur from the Late Cretaceous period of France. The type and only species is Mistralazhdarcho maggii.

<i>Cryodrakon</i> Genus of large azhdarchid pterosaur from the Late Cretaceous

Cryodrakon is a genus of azhdarchid pterosaur that lived during the Late Cretaceous period in what is now Canada. It contains a single species, Cryodrakon boreas, recovered from the Dinosaur Park Formation.

The Sebeș Formation is a geological formation in Romania. It is of Maastrichtian age. It is laterally equivalent to the Sard Formation. The base of the formation consists of claystones interbedded with sandstones and conglomerates. It is well known for its fossils which form a component of the Hațeg Island fauna.

Albadraco is an azhdarchid pterosaur genus that during the Late Cretaceous lived in the area of modern Romania. The type species is Albadraco tharmisensis.

<i>Wellnhopterus</i> Genus of azhdarchid pterosaur from the Late Cretaceous

Wellnhopterus is an azhdarchid pterosaur recovered from the Late Cretaceous Javelina Formation in Texas that was previously identified as a thalassodromine. It consists of a set of upper and lower jaws, as well as some cervical vertebrae and a fragmentary long bone. In July 2021, the jaws were given the genus name "Javelinadactylus", with the type and only species as "J. sagebieli"; however, this article has now been retracted. In a paper published in December 2021, the complete holotype was independently named Wellnhopterus, with the only species being W. brevirostris. As of 2022, this is the formal name of this pterosaur.

References

  1. 1 2 3 4 5 6 7 8 9 10 Vremir, M. T. S.; Kellner, A. W. A.; Naish, D.; Dyke, G. J. (2013). Viriot, Laurent (ed.). "A New Azhdarchid Pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: Implications for Azhdarchid Diversity and Distribution". PLOS ONE. 8 (1): e54268. Bibcode:2013PLoSO...854268V. doi: 10.1371/journal.pone.0054268 . PMC   3559652 . PMID   23382886.
  2. Longrich, Nicholas R.; Martill, David M.; Andres, Brian; Penny, David (2018). "Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary". PLOS Biology. 16 (3): e2001663. doi: 10.1371/journal.pbio.2001663 . PMC   5849296 . PMID   29534059.