Keresdrakon | |
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holotype specimen | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Order: | † Pterosauria |
Suborder: | † Pterodactyloidea |
Clade: | † Azhdarchoidea |
Genus: | † Keresdrakon Kellner et al. 2019 |
Type species | |
†Keresdrakon vilsoni Kellner et al. 2019 |
Keresdrakon is an extinct genus of azhdarchoid pterosaur from the Goio-Erê Formation of Brazil, which dates back to the Early Cretaceous period (Aptian-Albian stages), 125 to 100.5 million years ago. Keresdrakon contains a single species, Keresdrakon vilsoni. [2]
In 1971, Alexandre Dobruski and his son João Gustavo Dobruski, discovered a fossil site near Cruzeiro do Oeste in Paraná. Only in 2011, paleontologists Paulo César Manzig and Luiz C. Weinschütz visited the location. A bone bed proved to be present with hundreds of specimens of a pterosaur that in 2014 was named Caiuajara . Among them were some bones belonging to a second pterosaur species. These remains, both of Caiuajara and the new taxon, were prepared by volunteer Vilson Greinert. [2]
In 2019, the type species Keresdrakon vilsoni was named and described by Alexander Wilhelm Armin Kellner, Luiz Carlos Weinschütz, Borja Holgado, Renan Alfredo Machado Bantim and Juliana Manso Sayão. The generic name combines the Keres, evil spirits from Greek mythology, with the Greek drakon, "dragon". The specific name honors Greinert. As the name appeared in an electronic publication, Life Science Identifiers were needed for its validity. [2]
The holotype, CP.V 2069, was found in bonebed C, a sandstone layer. The strata in which the fossils have been discovered were initially thought to belong to the Rio Paraná Formation but later were assigned to the Goio-Erê Formation. The age of this formation is disputed; it could be as old as the Aptian but also as young as the Campanian. The holotype consists of a partial skeleton with skull. It contains the snout, a quadrate bone, the lower jaws, two neck vertebrae, four back vertebrae, the breastbone, belly ribs, the right shoulderblade, two humeri, a radius, two thighbones, a shinebone, the left ilium, the right pubic bone and the left ischium. The skeleton is not articulated. The bones have largely been three-dimensionally preserved, with little compression, and represent a subadult individual. Additional material from the same bonebed was assigned to the taxon as paratypes and referred material. [2]
The phylogenetic analysis in the description recovered Keresdrakon as a tapejaromorph azhdarchoid, as the sister taxon to the rest of the clade. [2]
Azhdarchoidea |
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A 2022 study by Rodrigo Pêgas and colleagues recovered Keresdrakon as the sister taxon to Alanqa in a basal position among azhdarchoids. [3]
The fossils of Keresdrakon were found in direct association with the tapejarid Caiuajara and the noasaurid theropod Vespersaurus , confirming that these species were sympatric. Among pterosaurs, this is the first direct evidence of sympatry, i.e. direct association instead of being found in the same stratigraphic unit. Of the three taxa in the bone beds, Caiuajara is the most common, and Keresdrakon is the least common. The lizard Gueragama was also likely part of this paleocommunity. Sedimentological data indicates that the environment of the Goio-Erê Formation was a desert, and the azhdarchid-like rostrum of Keresdrakon implies it may have been an opportunistic predator in this environment. [2]
Cearadactylus is a genus of large anhanguerid pterodactyloid pterosaur from the Romualdo Formation of Brazil, South America. Fossil remains of Cearadactylus dated back to the Albian stage of the Early Cretaceous period, about 112 million years ago. The only known species is C. atrox, described and named in 1985 by Giuseppe Leonardi and Guido Borgomanero. The name refers to the Brazilian state Ceará, and combines this with Greek daktylos, "finger", a reference to the wing finger of pterosaurs. The Latin atrox means "frightful", a reference to the fearsome dentition of the species.
Tupuxuara is a genus of thalassodromid pterosaur from the Albian stage of the Early Cretaceous period, about 112 million years ago. Its remains were found in what is now the Romualdo Formation of the Santana Group in Brazil. Tupuxuara was named in 1988 by paleontologists Alexander Kellner and Diógenes de Almeida Campos. The name Tupuxuara means "Familiar spirit" referring to a familiar spirit in the mythology of the Tupi people in Brazil. Two species have been named, T. longicristatus, the type species, and T. leonardii. An additional species has been named in 2013, T. deliradamus. However, the validity of this species has been put into question and it may not even belong to Tupuxuara.
Tapejaridae are a family of pterodactyloid pterosaurs from the Cretaceous period. Members are currently known from Brazil, England, Hungary, Morocco, Spain, the United States, and China. The most primitive genera were found in China, indicating that the family has an Asian origin.
Eopteranodon is a genus of tapejarid pterosaur from the Aptian-age Lower Cretaceous Yixian Formation of Beipiao City, Liaoning, China. The genus was named in 2005 by paleontologists Lü Junchang and Zhang Xingliao. The type species is Eopteranodon lii. A second species, E. yixianensis, was named in 2023, but its validity has been questioned.
Chaoyangopterus is a genus of chaoyangopterid pterosaur known from a partial skeleton found in Liaoning, China. Chaoyangopterus was found in rocks dating back to the Aptian-age Lower Cretaceous Jiufotang Formation of Dapingfang, Chaoyang.
Jidapterus is a genus of chaoyangopterid pterosaur from the Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China. The genus was in 2003 named by Dong Zhiming, Sun Yue-Wu and Wu Shao-Yuan. The type species is Jidapterus edentus. The genus name is derived from Jílín Dàxué or "Jilin University" and a Latinized Greek pteron, "wing". The specific name means "toothless" in Latin.
Ornithocheiroidea is a group of pterosaurs within the extinct suborder Pterodactyloidea. They were typically large pterosaurs that lived from the Early to Late Cretaceous periods, with fossil remains found all over the world except Antarctica.
Azhdarchoidea 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 one tentative member, Tendaguripterus, that lived in the Late Jurassic period. The largest azhdarchoids include members of the family Azhdarchidae, examples of these are Quetzalcoatlus, Hatzegopteryx, and Arambourgiania. Other notable pterosaur families belonging to the Azhdarchoidea are the Tapejaridae, the Thalassodromidae, and the Chaoyangopteridae. This group contains some of the most advanced members of the pterosaur order.
Shenzhoupterus is a genus of chaoyangopterid pterosaur from the Jiufotang Formation of modern-day Liaoning, China. Fossil remains of Shenzhoupterus date back to the Early Cretaceous period, approximately 120 million years ago.
Hongshanopterus is a genus of pterodactyloid pterosaur from the Lower Cretaceous Jiufotang Formation of Liaoning, China.
Chaoyangopteridae is a family of pterosaurs within the larger group Azhdarchoidea. Chaoyangopterids lived mostly during the Early Cretaceous period, though possible members, Microtuban, Xericeps and Argentinadraco, may extend the fossil range to the Late Cretaceous.
Guidraco is an extinct genus of toothed pterodactyloid pterosaur known from the Early Cretaceous of Liaoning Province, northeast China. According to many recent studies, Guidraco is a member of the group Anhanguerinae, a subfamily belonging to the larger group Anhangueridae.
Caupedactylus is an extinct genus of tapejarid azhdarchoid pterosaur known from the Early Cretaceous period of what is now the Romualdo Formation of the Araripe Basin in northeastern Brazil. The type and only species of Caupedactylus is Caupedactylus ybaka.
Caiuajara is an extinct genus of tapejarid pterosaur from the Early Cretaceous period of Brazil. It is known from a single type species, Caiuajara dobruskii.
Maaradactylus is a genus of anhanguerid pterodactyloid pterosaur known from the Lower Cretaceous period of the Romualdo Formation of northeastern Brazil.
Tapejaroidea is a group of pterosaurs belonging to the clade Ornithocheiroidea. Tapejaroids lived from the Early to Late Cretaceous periods, with one possible member, Tendaguripterus, extending the fossil range to the Late Jurassic period. Tapejaroidea contains two groups, the Dsungaripteridae and the Azhdarchoidea, which in turn includes the azhdarchids, the group that contains some of the largest flying animals. The group was named by Brazilian paleontologist Alexander Wilhelm Armin Kellner in 1996.
Vespersaurus is a genus of noasaurid theropod dinosaur from the Cretaceous Rio Paraná Formation in the Paraná Basin, Brazil. The type and only species is V. paranaensis, which would have lived in the giant prehistoric Botucatu Desert.
The Goio-Erê Formation is a geological formation in Brazil. It is sometimes thought to be deposited between the Turonian and Campanian stages of the Late Cretaceous, but an Aptian-Albian date has also been proposed. It primarily consists of sandstone and was deposited in a desert environment. It is known for its exceptional 3-D preservation of fossils, which include those of the pterosaurs Keresdrakon ,Caiuajara and Torukjara the dinosaur Berthasaura as well as the iguanian lizard Gueragama. It is laterally equivalent to the Rio Paraná Formation.
Berthasaura is an extinct genus of ceratosaurian theropod dinosaurs from the Early Cretaceous Goio-Erê Formation of Paraná, Brazil. The genus contains a single species, Berthasaura leopoldinae, known from a nearly complete skeleton.
Torukjara is an extinct genus of tapejarin pterodactyloid pterosaurs from the Early Cretaceous "Pterosaur Graveyard" of Brazil. The genus contains a single species, T. bandeirae, known from several specimens. The Torukjara fossil material was originally assigned to Caiuajara, but several anatomical differences indicate that both similar species coexisted in the ecosystem.