Euctenochasmatia

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Euctenochasmatians
Temporal range: Late Jurassic - Early Cretaceous, 152–105  Ma
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Cast of the sub-adult type specimen of the basal member Pterodactylus antiquus
Pterodaustro guinazui.jpg
Cast of fossil specimen of the ctenochasmatid Pterodaustro guinazui
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Suborder: Pterodactyloidea
Infraorder: Archaeopterodactyloidea
Clade: Euctenochasmatia
Unwin, 2003
Subgroups

Euctenochasmatia is an extinct group of pterodactyloid pterosaurs. It was named by David Unwin in 2003 as the group that contains the most recent common ancestor of Pterodactylus and Ctenochasma , and all their descendants. [1]

Contents

Euctenochasmatians were specialized pterosaurs that had elongated necks as well as specialized teeth. A peculiar family within this group is the Ctenochasmatidae, which most of the members had very distinguishing teeth that were lined within their elongated snouts. [2] A genus called Pterofiltrus only had 112 teeth, but these teeth cover about 55.8% of the total skull, and the skull itself measured about 208 millimeters (8.2 in) in length. [3]

Description

Restored skull of Pterodaustro Pterodaustro skull.jpg
Restored skull of Pterodaustro

Euctenochasmatians had very distinctive features in comparison to other pterosaurs, including the shape of their jaws, as well as their highly specialized teeth. These teeth are thought to have been used for filter-feeding, the genus Pterodaustro for example, had a long snout and its lower jaws curve strongly upwards, and the tangent at the point of the snout was perpendicular to that of the jaw joint. Pterodaustro has around a thousand baleen-like teeth in its lower jaws that might have been used to strain crustaceans, plankton, algae, and other small creatures from the water. The teeth of Pterodaustro are unique within pterosaurs, and no other discovered genera had this type of teeth. [4] [5]

Other members of this group, such as the gallodactylids, differ from other euctenochasmatians in several distinct features, including having fewer than 50 teeth, and were only present in the jaw tips; rounded crests were also present on the rear portion of the skull and jaws but not near the ends of their snouts. [6] Similarly, the ctenochasmatid Feilongus also had its teeth confined within its jaw tips, as well as having crests on the rear portion of the skull and jaws, but differed Feilongus from the gallodactylids by having a possible pronounced overbite, and 76 teeth, which were needle-like. [7]

One of the largest toothed pterosaurs was Moganopterus , it was, yet again, a ctenochasmatid, and was similar in build to Feilongus. What made Moganopterus distinct was its size; while Feilongus had a wingspan of about 2.4 meters (7.9 ft), Moganopterus had an impressive wingspan of more than 7 meters (23 ft), making it more than three times larger than Feilongus. [8]

Classification

Researchers such as David Unwin, have traditionally defined the dubious family Pterodactylidae in such a way to ensure it is nested within the clade Ctenochasmatoidea. In 2003, Unwin defined the same clade (Pterodactylus + Pterodaustro), but erected the name Euctenochasmatia instead of Pterodactylidae for his conclusion. [9] Unwin had considered Euctenochasmatia to be a subgroup within Ctenochasmatoidea, similar to his former conclusion of Pterodactylidae, but most analyses have since found the genus Pterodactylus to be more primitive than previously thought, making the clade Euctenochasmatia the more inclusive group containing both Pterodactylus and Ctenochasmatoidea. [10]

Below is cladogram following a topology recovered by Brian Andres, using the most recent iteration of his data set (Andres, 2021). Andres' analysis found Pterodactylus to be a close relative of the ctenochasmatoids. [11]

  Pterodactyloidea  
Juvenile specimen of Cycnorhamphus suevicus Cycnorhamphus suevicus.jpg
Juvenile specimen of Cycnorhamphus suevicus

Earlier, in 2017, Steven Vidovic and David Martill had recovered a significantly different set of relationships for early pterodactyloids. They placed Pterodactylus outside Euctenochasmatia, as the sister taxon of the more inclusive group Lophocratia. [1]

  Pterodactyloidea  

Related Research Articles

<i>Pterodaustro</i> Genus of ctenochasmatid pterosaur from the Early Cretaceous

Pterodaustro is a genus of ctenochasmatid pterodactyloid pterosaur from South America. Its fossil remains dated back to the Early Cretaceous period, about 105 million years ago.

<i>Cearadactylus</i> Genus of anhanguerid pterosaur from the Early Cretaceous

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.

<i>Germanodactylus</i> Genus of germanodactylid pterosaur from the Late Jurassic

Germanodactylus is a genus of germanodactylid pterodactyloid pterosaur from Upper Jurassic-age rocks of Germany, including the Solnhofen Limestone. Its specimens were long thought to pertain to Pterodactylus. The head crest of Germanodactylus is a distinctive feature.

<span class="mw-page-title-main">Pterodactyloidea</span> Suborder of monofenestratan pterosaurs

Pterodactyloidea is one of the two traditional suborders of pterosaurs, and contains the most derived members of this group of flying reptiles. They appeared during the middle Jurassic Period, and differ from the basal rhamphorhynchoids by their short tails and long wing metacarpals. The most advanced forms also lack teeth, and by the late Cretaceous, all known pterodactyloids were toothless. Many species had well-developed crests on the skull, a form of display taken to extremes in giant-crested forms like Nyctosaurus and Tupandactylus. Pterodactyloids were the last surviving pterosaurs when the order became extinct at the end of the Cretaceous Period, together with the non-avian dinosaurs and most marine reptiles.

<span class="mw-page-title-main">Gallodactylidae</span> Family of ctenochasmatoid pterosaurs

Gallodactylidae is a group of pterosaurs within the suborder Pterodactyloidea. Gallodactylids differed from other related pterosaurs in several distinct features, including fewer than 50 teeth present only in the jaw tips, and rounded crests present on the rear portion of the skull and jaws but not near the ends of their snouts. At least some species possessed jaw flanges, possibly used to bissect hard-shelled prey.

<span class="mw-page-title-main">Pterodactylidae</span> Extinct clade of reptiles

Pterodactylidae is a controversial group of pterosaurs. During the 2000s and 2010s, several competing definitions for the various Jurassic pterodactyloid groups were proposed. Pereda-Suberbiola et al. (2012) used Fabien Knoll's (2000) definition of the name Pterodactylidae. Knoll had defined Pterodactylidae as a clade containing "Pterodactylus antiquus, Ctenochasma elegans, their most recent common ancestor and all its descendants". Using this definition with the analysis conducted by Pereda-Suberbiola et al. (2012) meant that Ctenochasmatoidea was nested inside Pterodactylidae.

Boreopterus is a genus of boreopterid pterodactyloid pterosaur from the Barremian-Aptian-age Lower Cretaceous Yixian Formation of Dalian, Liaoning, China.

<i>Diopecephalus</i> Genus of euctenochasmatian pterosaur from the Late Jurassic

Diopecephalus is a genus of pterodactyloid pterosaur from the Lower Tithonian of the Lithographic Limestone, Bavaria, Germany. The type and only species is D. kochi, although the name has been applied to Pterodactylus longicollum, with longicollum erroneously listed as the type species.

<i>Feilongus</i> Genus of ctenochasmatid pterosaur from the Early Cretaceous

Feilongus is an extinct genus of ctenochasmatid pterodactyloid pterosaur from the Barremian–Aptian-age Lower Cretaceous Yixian Formation of Beipiao, Liaoning, China.

<i>Ludodactylus</i> Genus of anhanguerid pterosaur from the Early Cretaceous

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.

<span class="mw-page-title-main">Lonchodectidae</span> Family of pteranodontoid pterosaurs

Lonchodectidae or Lonchodraconidae is a group of pterosaurs within the clade Pterodactyloidea. It has variously been considered to be within Ctenochasmatoidea, Azhdarchoidea and Pteranodontoidea. They are notable for their high, conical tooth sockets and raised alveolar margins.

<span class="mw-page-title-main">Ctenochasmatoidea</span> Superfamily of archaeopterodactyloid pterosaurs

Ctenochasmatoidea is a group of early pterosaurs within the suborder Pterodactyloidea. Their remains are usually found in what were once coastal or lake environments. They generally had long wings, long necks, and highly specialized teeth.

<span class="mw-page-title-main">Azhdarchoidea</span> Superfamily of ornithocheiroid pterosaurs

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. The Azhdarchoidea has been recovered as either closely related to the Ctenochasmatoidea, as the sister taxon of the Pteranodontoidea within the Ornithocheiroidea, or within the Tapejaroidea, which in turn was also within the Ornithocheiroidea.

<i>Zhenyuanopterus</i> Genus of boreopterid pterosaur from the Early Cretaceous

Zhenyuanopterus is a genus of boreopterid pterosaur which is known from Lower Cretaceous Yixian Formation of Liaoning, China. It contains one species, Zhenyuanopterus longirostris, which was first described and named by Lü Junchang.

<span class="mw-page-title-main">Boreopteridae</span> Family of pteranodontoid pterosaurs

Boreopteridae is a group of pterodactyloid pterosaurs from the Aptian-age Lower Cretaceous Yixian Formation of Liaoning, China.

<i>Moganopterus</i> Genus of ctenochasmatid pterosaur from the Early Cretaceous

Moganopterus is an extinct genus of ctenochasmatid pterosaur from the Early Cretaceous of western Liaoning Province, China.

<span class="mw-page-title-main">Archaeopterodactyloidea</span> Infraorder of pterodactyloid pterosaurs

Archaeopterodactyloidea is an extinct clade of pterodactyloid pterosaurs that lived from the middle Late Jurassic to the latest Early Cretaceous periods of Africa, Asia, Europe and North America. It was named by Alexander Wilhelm Armin Kellner in 1996 as the group that contains Germanodactylus, Pterodactylus, the Ctenochasmatidae and the Gallodactylidae. In 2003, Kellner defined the clade as a node-based taxon consisting of the last common ancestor of Pterodactylus, Ctenochasma and Gallodactylus and all its descendants. Although phylogenetic analyses that based on David Unwin's 2003 analysis do not recover monophyletic Archaeopterodactyloidea, phylogenetic analyses that based on Kellner's analyses, or the analyses of Brian Andres recover monophyletic Archaeopterodactyloidea at the base of the Pterodactyloidea.

<i>Forfexopterus</i> Genus of ctenochasmatid pterosaur from the Early Cretaceous

Forfexopterus is a genus of ctenochasmatid pterosaur from the Early Cretaceous Jiufotang Formation in China. It contains a single species, F. jeholensis, named from a mostly complete skeleton by Shunxing Jiang and colleagues in 2016. A second specimen, consisting of a wing, was described in 2020. While the first specimen is larger, it shows signs of being less mature than the second specimen, indicating that the developmental trajectories of Forfexopterus were variable. Like other ctenochasmatids, Forfexopterus had a long, low skull filled with many slender teeth; unlike other members of the group, however, it did not have a spatula-shaped snout tip or crests, and its teeth were more curved. A single characteristic distinguishes Forfexopterus from all other members of the wider group Archaeopterodactyloidea: of the four phalanx bones in its wing finger, the first was shorter than the second but longer than the third.

<i>Liaodactylus</i> Genus of ctenochasmatid pterosaur from the Late Jurassic

Liaodactylus is a genus of filter-feeding ctenochasmatid pterosaur from the Jurassic of China. The genus contains one species, L. primus, described by Zhou et al. in 2017. As an adaptation to filter-feeding, Liaodactylus had approximately 150 long, comb-like teeth packed closely together. It is both the earliest known ctenochasmatid and the first filter-feeding pterosaur from the Jurassic Yanliao Biota. Later and more specialized ctenochasmatids differ from Liaodactylus in having longer snouts, smaller openings in the skull, and more teeth. Within the Ctenochasmatidae, Liaodactylus was most closely related to the European Ctenochasma.

<i>Balaenognathus</i> Extinct genus of ctenochasmatid pterosaurs

Balaenognathus is an extinct genus of ctenochasmatid pterosaurs from the Late Jurassic Torleite Formation of Bavaria, Germany. The genus contains a single species, B. maeuseri, known from a nearly-complete, articulated skeleton.

References

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  4. Chinsamy, A., Codorniú, L., and Chiappe, L. M. (2008). "Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guinazui". Biology Letters . 4 (3): 282–285. doi:10.1098/rsbl.2008.0004. PMC   2610039 . PMID   18308672.{{cite journal}}: CS1 maint: multiple names: authors list (link)
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