Uktenadactylus Temporal range: Early Cretaceous, | |
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U. wadleighi holotype snout in multiple views | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Order: | † Pterosauria |
Suborder: | † Pterodactyloidea |
Family: | † Anhangueridae |
Subfamily: | † Coloborhynchinae |
Genus: | † Uktenadactylus Rodrigues & Kellner, 2009 |
Type species | |
†Coloborhynchus wadleighi Lee, 1994 | |
Species | |
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Synonyms | |
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Uktenadactylus is a genus of anhanguerid pterodactyloid pterosaurs from the Lower Cretaceous Paw Paw Formation of Texas, United States and the Wessex Formation on the Isle of Wight, England. Fossil remains of Uktenadactylus dated back to the Early Cretaceous period (Barremian to Cenomanian stages), from about 125 to 100 million years ago.
In 1994, Yuong Nam-Lee named a new species within the genus Coloborhynchus : Coloborhynchus wadleighi, based on a partial snout found in 1992 in Albian layers in Tarrant County, holotype SMU 73058 (Shuler Museum of Paleontology, Southern Methodist University at Dallas). The specific name honors the collector of the fossil, Chris Wadleigh. The reference of the species to the genus Coloborhynchus was based on the fact that both C. wadleighi and the type species of Coloborhynchus, Coloborhynchus clavirostris, share the trait of having three pairs of teeth laterally placed within a broad snout tip. This would distinguish both from the species Criorhynchus simus and justify a revival of the genus Coloborhynchus that since an analysis by Reginald Walter Hooley in 1914 [1] had generally been considered identical to the genus Criorhynchus or the genus the latter had again been sunk into, Ornithocheirus . [2]
As a result of the reappearance of the concept European workers referred many species discovered in South-America to Coloborhynchus, a practice rejected by most South-American researchers. In 2009 a study by the Brazilian paleontologists Taissa Rodrigues and Alexander Kellner concluded that Coloborhynchus comprised only a single species, its type species, C. clavirostris. Accordingly, in the same publication they created a new genus for C. wadleighi: Uktenadactylus. The genus name is derived from Uktena, a giant horned snake from the mythology of the Cherokee and Greek daktylos, "finger", a common element in the names of pterosaurs since Pterodactylus , referring to their typical wing finger. [3]
In 2020, Borja Holgado and Rodrigo Pêgas named a new species of Uktenadactylus, U. rodriguesae after Rodrigues, known from a snout fragment (cataloged as IWCMS 2014.82) found on the Isle of Wight. [4] This specimen had previously been described in 2015 by David Martill as an indeterminate member of the genus Coloborhynchus on account of the anteriorly-projecting teeth at the snout tip. [5] Holgado and Pêgas recognized that it shared features with U. wadleighi, and thus assigned it as a new species in the same genus. [4]
The holotype and only specimen of U. wadleighi, the partial snout, has a length of about fifteen centimetres and consists of the front end of the skull, containing the premaxilla and a small part of the maxilla. On top the base of a crest is present, gradually curving upwards and ending at a height of 7.5 centimeters (3.0 in), having attained at that point a thickness of 4 millimeters (0.16 in). The snout broadens towards the front. On the left side eight tooth sockets or alveoli are visible, on the right side six. The first pair of teeth was located in the flat tip of the snout, pointing forwards. The alveoli at first increase in size from the tip towards the back, the third pair being the largest with a diameter of either 17.6 millimeters (0.69 in) or 17.7 millimeters (0.70 in). The fourth pair is much smaller; to the back gradually the tooth sockets again increase in size. Thus a "prey grab" is formed. According to Rodrigues and Kellner the species has two unique traits: the presence of an oval depression above and in between the first pair of teeth and of a ventral medial depression between the second pair of teeth, a circular hollow positioned on the lower edge of the snout tip that Lee had interpreted as a possible pneumatic foramen. [3] The holotype of U. rodriguesae shares the oval depression and also a bulbous projection on the palate with the holotype of U. wadleighi. However, it differs from U. wadleighi in that the depression is shallower, the second pair of teeth projects more laterally, and the margins of the deltoid facet (an upturned region of the front palate) are concave as opposed to straight. [4]
Rodrigues and Kellner base the distinction between Uktenadactylus and Coloborhynchus clavirostris on several stratigraphical, methodological and phylogenetic considerations. There is a possible age difference of perhaps over thirty million years between the Berriasian-Valanginian British and the younger Albian-Cenomanian American form. Because both taxa are based on very limited remains, that however, even within these limits are clearly distinguishable on the species level, they reject a rash assumption of generic identity. Also the uncertain affinity with the closely related form Siroccopteryx would make such an assumption problematical. Rodrigues and Kellner identify only one shared derived trait for Uktenadactylus and Coloborhynchus clavirostris: an extreme enlargement of the second and third pairs of teeth. Differences between the taxa include the more forward position of the crest with C. clavirostris, beginning at the very tip of the snout; a deeper palatal groove and shallow grooves running parallel to the ridge of the front part of the palate; a depression located below the first alveoli and a more lateral position of the second, third and fourth tooth pairs whereas the fifth and sixth pair are to the contrary much closer to the midline of the skull. Both forms share some derived traits with Siroccopteryx: the second and third teeth pairs are larger than the fourth; the tip of the snout is flat causing the "prey grab" to be rectangular in cross-section and a similar thickness of the crest. The authors conclude from this that the three taxa likely formed an, as yet unnamed, clade together within the Anhangueridae. [3]
In 2013, a topology by Andres & Myers placed Uktenadactylus within the family Ornithocheiridae, as the sister taxon of Coloborhynchus clavirostris, though in the analysis, Uktenadactylus was identified as Coloborhynchus wadleighi. [6] In 2019, a slightly different topology by Jacobs et al. also recovered Uktenadactylus within the Ornithocheiridae, but as the sister taxon of several Coloborhynchus species, and identified with its current name. Their cladogram is shown on the left. [7] However, many subsequent analyses in the same year as well as in 2020 have recovered Uktenadactylus within the family Anhangueridae, more specifically within the subfamily Coloborhynchinae. [8] [9] [10] The cladogram on the right is a topology based on the phylogenetic analysis made by Borja Holgado and Rodrigo Pêgas in 2020, where they recovered Uktenadactylus as the sister taxon of Nicorhynchus within the Coloborhynchinae. [4]
Topology 1: Jacobs et al. (2019). [7]
| Topology 2: Holgado & Pêgas (2020). [4]
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Caulkicephalus is a genus of anhanguerid pterosaur from the Isle of Wight off the coast of England. It lived during the Early Cretaceous period, about 130 million years ago.
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.
Ornithocheirus is a pterosaur genus known from fragmentary fossil remains uncovered from sediments in the United Kingdom and possibly Morocco.
Tropeognathus is a genus of large pterosaurs from the late Early Cretaceous of South America. This genus is considered to be a member of the family Anhangueridae, however, several studies have also recovered it within another family called Ornithocheiridae. Both of these families are diverse groups of pterosaurs known for their keel-tipped snouts and large size. Tropeognathus is regarded as the largest pterosaur found in the Southern Hemisphere, only rivaled by the huge azhdarchids. The type and only species is Tropeognathus mesembrinus. Fossil remains of Tropeognathus have been recovered from the Romualdo Formation, which is a Lagerstätte located in the Santana Group of the Araripe Basin in northeastern Brazil.
Siroccopteryx is an extinct genus of anhanguerid pterodactyloid pterosaur, known from middle Cretaceous sediments in modern-day Morocco. Some researchers, such as David M. Unwin, consider the genus a junior synonym of Coloborhynchus.
Coloborhynchus is a genus of pterodactyloid pterosaur belonging to the family Anhangueridae, though it has also been recovered as a member of the Ornithocheiridae in some studies. Coloborhynchus is known from the Lower Cretaceous of England, and depending on which species are included, possibly the Albian and Cenomanian ages as well. Coloborhynchus was once thought to be the largest known toothed pterosaur, however, a specimen of the closely related Tropeognathus is now thought to have had a larger wingspan.
Ludodactylus is a genus of anhanguerid pterodactyloid pterosaur from the Early Cretaceous period of what is now the Crato Formation of the Araripe Basin in Ceará, Brazil. The type and only species is L. sibbicki. The generic name Ludodactylus refers to the fact that the animal had the combination of teeth and a Pteranodon-like head crest, similar to many toy pterosaurs, and no such creature was known to exist until the discovery of Ludodactylus. However, Ludodactylus is not the only pterosaur known to possess these features, its very close relative Caulkicephalus is another example.
Lonchodectidae or Lonchodraconidae is a group of pterosaurs within the clade Pterodactyloidea. It has variously been considered to be within Ctenochasmatoidea, Azhdarchoidea and Pteranodontia. They are notable for their high, conical tooth sockets and raised alveolar margins.
Ornithocheiridae is a group of pterosaurs within the suborder Pterodactyloidea. These pterosaurs were among the last to possess teeth. Members that belong to this group lived from the Early to Late Cretaceous periods, around 140 to 90 million years ago.
Aussiedraco is a genus of targaryendraconian pterodactyloid pterosaur from the early Cretaceous of Australia.
Ornithocheirae is an extinct clade of pteranodontoid pterosaurs from the Early Cretaceous to the Late Cretaceous of Asia, Europe, North America and South America. It was named by Harry Seeley in 1870 as a family that contains Ornithocheirus and its relatives. The name was emended to Ornithocheiridae, to match the requirements of the ICZN Code that a family-ranked clade should end with an -idae suffix. Brian Andres (2010) in his review of pterosaur phylogeny, defined the name Ornithocheirae phylogenetically, as a node-based taxon consisting of the last common ancestor of Anhanguera and Ornithocheirus and all its descendants. Thus Ornithocheirae is defined to include two families, the Anhangueridae and the Ornithocheiridae, following the opinion of Alexander Kellner and Andres that these families should not be synonymized based on their original phylogenetical definitions. However, subsequent studies in 2019 have found Ornithocheirae to be a more inclusive group containing both Anhangueria and Targaryendraconia.
Cimoliopterus is a genus of pterosaur that lived during the Late Cretaceous in what is now England and the United States. The first known specimen, consisting of the front part of a snout including part of a crest, was discovered in the Grey Chalk Subgroup of Kent, England, and described as the new species Pterodactylus cuvieri in 1851. The specific name cuvieri honours the palaeontologist George Cuvier, whereas the genus Pterodactylus was then used for many pterosaur species that are not thought to be closely related today. It was one of the first pterosaurs to be depicted as models in Crystal Palace Park in the 1850s. The species was subsequently assigned to various other genera, including Ornithocheirus and Anhanguera. In 2013, the species was moved to a new genus, as Cimoliopterus cuvieri; the generic name Cimoliopterus is derived from the Greek words for "chalk" and "wing". Other specimens and species have also been assigned to or synonymised with the species with various levels of certainty. In 2015, a snout discovered in the Britton Formation of Texas, US, was named as a new species in the genus, C. dunni; the specific name honours its collector, Brent Dunn.
Lonchodraco is a genus of lonchodraconid pterodactyloid pterosaur from the Late Cretaceous of southern England. The genus includes species that were previously assigned to other genera.
Camposipterus is a genus of pterodactyloid pterosaur from the Early Cretaceous of England. Fossil remains of Camposipterus dated back to the Early Cretaceous, about 112 million years ago.
Anhangueria is a group of pterosaurs belonging to the clade Pteranodontoidea. Fossil remains of this group date back from the Early to Late Cretaceous periods, around 140 to 92.5 million years ago. Anhangueria was named by paleontologists Taissa Rodrigues and Alexander Kellner in a review of Ornithocheirus species in 2013, they defined the clade as a branch-based taxon consisting of all pteranodontoids more closely related to Anhanguera blittersdorffi than to Istiodactylus latidens and Cimoliopterus cuvieri.
Maaradactylus is a genus of anhanguerid pterodactyloid pterosaur known from the Lower Cretaceous period of the Romualdo Formation of northeastern Brazil.
Ornithocheiromorpha is a group of pterosaurs within the suborder Pterodactyloidea. Fossil remains of this group date back from the Early to Late Cretaceous periods, around 140 to 92.5 million years ago. Ornithocheiromorphs were discovered worldwide except Antarctica, though most genera were recovered in Europe, Asia and South America. They were the most diverse and successful pterosaurs during the Early Cretaceous, but throughout the Late Cretaceous they were replaced by better adapted and more advanced pterosaur species such the pteranodontids and azhdarchoids. The Ornithocheiromorpha was defined in 2014 by Andres and colleagues, and they made Ornithocheiromorpha the most inclusive clade containing Ornithocheirus, but not Pteranodon.
Iberodactylus is a genus of pterodactyloid pterosaurs belonging to the clade Anhangueria, that during the Early Cretaceous lived in the area of present Spain. The type species is Iberodactylus andreui.
Nicorhynchus is a genus of anhanguerid pterosaur from the Cretaceous period. It contains two species, the type species, N. capito, from the Cambridge Greensand of England, and N. fluviferox from the Kem Kem Group of Morocco. These species were previously assigned to Coloborhynchus.
Aerodraco is a genus of anhanguerid pterosaur from the Albian–Cenomanian-age Cambridge Greensand of England. It contains only one species, Aerodraco sedgwickii. It was originally assigned to the genus Pterodactylus.