Uktenadactylus
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''Uktenadactylus'' is a
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of anhanguerid pterodactyloid
pterosaur Pterosaurs are 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 million to 66 million years ago). Pterosaurs are the earli ...
s from the
Lower Cretaceous Lower may refer to: * ''Lower'' (album), 2025 album by Benjamin Booker * Lower (surname) * Lower Township, New Jersey *Lower Receiver (firearms) * Lower Wick Gloucestershire, England See also * Nizhny {{Disambiguation ...
Paw Paw Formation of
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, United States and the
Wessex Formation The Wessex Formation is a fossil-rich England, English geological formation that dates from the Berriasian to Barremian Stage (stratigraphy), stages of the Early Cretaceous. It forms part of the Wealden Group and underlies the younger Vectis Form ...
on the
Isle of Wight The Isle of Wight (Help:IPA/English, /waɪt/ Help:Pronunciation respelling key, ''WYTE'') is an island off the south coast of England which, together with its surrounding uninhabited islets and Skerry, skerries, is also a ceremonial county. T ...
, England. Fossil remains of ''Uktenadactylus'' dated back to the
Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...
period (
Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...
to
Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...
stages), from about 125 to 100 million years ago.


Discovery and naming

In 1994, Yuong Nam-Lee named a new species within the genus ''
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 Engla ...
'': ''Coloborhynchus wadleighi'', based on a partial snout found in 1992 in
Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...
layers in Tarrant County,
holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...
SMU 73058 ( Shuler Museum of Paleontology,
Southern Methodist University Southern Methodist University (SMU) is a Private university, private research university in Dallas, Texas, United States, with a satellite campus in Taos County, New Mexico. SMU was founded on April 17, 1911, by the Methodist Episcopal Church, ...
at
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). 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 In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
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 had generally been considered identical to the genus ''Criorhynchus'' or the genus the latter had again been sunk into, ''
Ornithocheirus ''Ornithocheirus'' (from Ancient Greek "ὄρνις", meaning bird, and "χεῖρ", meaning hand) is a pterosaur genus known from fragmentary fossil remains uncovered from sediments in the United Kingdom and possibly Morocco. Several species ha ...
''. 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 Myth is a genre of folklore consisting primarily of narratives that play a fundamental role in a society. For scholars, this is very different from the vernacular usage of the term "myth" that refers to a belief that is not true. Instead, the ...
of the
Cherokee The Cherokee (; , or ) people are one of the Indigenous peoples of the Southeastern Woodlands of the United States. Prior to the 18th century, they were concentrated in their homelands, in towns along river valleys of what is now southwestern ...
and Greek ''daktylos'', "finger", a common element in the names of pterosaurs since ''
Pterodactylus ''Pterodactylus'' (from ) is a genus of extinct pterosaurs. It is thought to contain only a single species, ''Pterodactylus antiquus'', which was the first pterosaur to be named and identified as a flying reptile and one of the first prehis ...
'', referring to their typical wing finger. 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 The Isle of Wight (Help:IPA/English, /waɪt/ Help:Pronunciation respelling key, ''WYTE'') is an island off the south coast of England which, together with its surrounding uninhabited islets and Skerry, skerries, is also a ceremonial county. T ...
. 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. Holgado and Pêgas recognized that it shared features with ''U. wadleighi'', and thus assigned it as a new species in the same genus.


Description

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 The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals h ...
and a small part of the
maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...
. On top the base of a crest is present, gradually curving upwards and ending at a height of , having attained at that point a thickness of . 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 or . 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. The holotype of ''U. rodriguesae'' shares the oval depression and also a bulbous projection on the
palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sep ...
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. 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 In the geological timescale, the Berriasian is an age/ stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 143.1 ±0.6 Ma and 137.05 ± 0.2 (million years ago) ...
-
Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 137.05 ± 0.2 Ma and 132.6 ± 0.2 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretac ...
British and the younger
Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...
-
Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...
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 ''Siroccopteryx'' is an extinct genus of anhanguerid pterodactyloid pterosaur which lived in Morocco during the Cenomanian stage of the Late Cretaceous. Some researchers, such as David M. Unwin, consider the genus a junior synonym of '' Colobor ...
'' 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 In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
together within the Anhangueridae.


Classification

In 2013, a topology by Andres & Myers placed ''Uktenadactylus'' within the family
Ornithocheiridae Anhangueridae (alternatively called Ornithocheiridae, meaning "bird hands") 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 E ...
, as the sister taxon of ''Coloborhynchus clavirostris'', though in the analysis, ''Uktenadactylus'' was identified as ''Coloborhynchus wadleighi''. 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. 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.Pêgas, R.V., Holgado, B., Leal, M.E.C., 2019. "''Targaryendraco wiedenrothi'' gen. nov. (Pterodactyloidea, Pteranodontoidea, Lanceodontia) and recognition of a new cosmopolitan lineage of Cretaceous toothed pterodactyloids", ''Historical Biology'', 1–15. doi:10.1080/08912963.2019.1690482 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. Topology 1: Jacobs ''et al.'' (2019). Topology 2: Holgado & Pêgas (2020).


See also

*
List of pterosaur genera This list of pterosaurs is a comprehensive listing of all Genus, genera that have ever been included in the order Pterosauria, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considere ...
*
Timeline of pterosaur research This timeline of pterosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and Biological taxonomy, taxonomic revisions of pterosaurs, the famed flying reptiles of the Mesozoic Era (ge ...


References

{{Portal bar, Paleontology, United States, United Kingdom Pteranodontoidea Early Cretaceous pterosaurs of North America Early Cretaceous reptiles of North America Taxa named by Alexander Kellner Fossil taxa described in 2009 Albian life