Thoracosaurus

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Thoracosaurus
Temporal range: Late Cretaceous–Early Paleocene
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Thoracosaurus macrorhynchus - Maastricht.jpg
Thoracosaurus isorhynchus skull
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodilia
Superfamily: Gavialoidea
Genus:Thoracosaurus
Leidy, 1852
Species
  • T. neocesariensis(de Kay, 1842 [originally Gavialis neocesariensis]) (type)
  • T. isorhynchus(Pomel, 1847)
  • T. scanicus

Thoracosaurus is an extinct genus of eusuchian crocodylomorph which existed during the Late Cretaceous and early Paleocene. The animal is usually regarded as a gavialoid crocodilian, [1] though the phylogenetic study published by Lee & Yates (2018) suggests that it might have been a non-crocodylian eusuchian. [2] The genus contains the species Thoracosaurus neocesariensis in North America [3] and Thoracosaurus isorhynchus (T. macrorhynchus being a junior synonym of T. isorhynchus) [4] in Europe. A number of species have been referred to this genus, but most are dubious. [1]

A genus is a taxonomic rank used in the biological classification of living and fossil organisms, as well as viruses, in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.

Eusuchia taxon of reptiles

The Eusuchia are a clade of crocodylomorphs that first appears in the Early Cretaceous with Hylaeochampsa. Along with Dyrosauridae and Sebecosuchia, they were the only crocodyliformes who survived the K-T extinction. Since the other two clades died out 35 and 11 million years ago, all living crocodilian species are eusuchians, as are many extinct forms.

Crocodylomorpha superorder of reptiles

Crocodylomorpha is a group of archosaurs that includes the crocodilians and their extinct relatives.

Thoracosaurus scanicus was a fairly large gavialoid, with a length of more than 4.4 m (14.4 ft) and a 55 cm skull. [5]

Gavialoidea superfamily of large reptiles

Gavialoidea is one of three superfamilies of crocodylians, the other two being Alligatoroidea and Crocodyloidea. Although many extinct species are known, only the gharial Gavialis gangeticus and the false gharial Tomistoma schlegelii are alive today.

Related Research Articles

Gavialidae family of reptiles

Gavialidae is a family of reptiles within the order Crocodilia. Gavialidae have conventionally consisted of only one surviving species, the gharial, which is native to India and Nepal. Many extinct species are also known. The false gharial has usually been thought to be a member of the family Crocodylidae based on several characters including skull morphology, but has sometimes been viewed as a member of this family due to general similarities in morphology and habit. However, numerous molecular studies have consistently shown the two species to be each other's closest living relative, supporting the view that they are in the same family.

<i>Allodaposuchus</i> genus of reptiles

Allodaposuchus is an extinct genus of crocodyliforms that includes four species that lived in what is now southern Europe during the Campanian and Maastrichtian stages of the Late Cretaceous. Although generally classified as a non-crocodylian crocodylomorph, it is sometimes placed as one of the earliest true crocodylians. Allodaposuchus is one of the most common Late Cretaceous crocodylomorphs from Europe, with fossils known from Spain, Romania, and France.

<i>Borealosuchus</i> genus of large reptiles

Borealosuchus is an extinct genus of crocodylians that lived from the Late Cretaceous to the Eocene in North America. It was named by Chris Brochu in 1997 for several species that had been assigned to Leidyosuchus. The species assigned to it are: B. sternbergii, the type species, from the Maastrichtian of Colorado, Montana, North Dakota, South Dakota, and Wyoming; B. acutidentatus, from the Paleocene of Saskatchewan; B. formidabilis, from the Paleocene of North Dakota; B. griffithi, from the Paleocene of Alberta; and B. wilsoni, from the Eocene of Wyoming. B. formidabilis is particularly well-known, represented by the remains of many individuals from the Wannagan Creek site in North Dakota.

<i>Gavialosuchus</i> genus of reptiles

Gavialosuchus is an extinct tomistomine from the early Miocene of Europe.

Argochampsa is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodilian, related to modern gharials. It lived in the Paleocene of Morocco. Described by Hua and Jouve in 2004, the type species is A. krebsi, with the species named for Bernard Krebs. Argochampsa had a long narrow snout, and appears to have been marine in habits.

<i>Aktiogavialis</i> species of reptile (fossil)

Aktiogavialis is an extinct genus of crocodylian that lived from the Oligocene until the Miocene in what is now the Caribbean. Two species have been described: Aktiogavialis puertoricensis from the Oligocene of Puerto Rico and Aktiogavialis caribesi from the Miocene of Venezuela.

<i>Dollosuchus</i> genus of reptiles (fossil)

Dollosuchus is an extinct tomistomine. It is a basal form possibly related to Kentisuchus, according to several phylogenetic analyses that have been conducted in recent years, and is the oldest known tomistomine to date. Fossils have been found from Belgium and the United Kingdom. It had large supratemporal fenestrae in relation to its orbits, similar to Kentisuchus and Thecachampsa.

Eogavialis is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodylian. It superficially resembles Tomistoma schlegelii, the extant false gharial, and consequently material from the genus was originally referred to Tomistoma. Indeed, it was not until 1982 that the name Eogavialis was constructed after it was realised that the specimens were from a more basal form.

Eothoracosaurus is an extinct genus of eusuchian crocodylomorph which existed during the Late Cretaceous and early Paleocene. The animal is usually regarded as a gavialoid crocodilian, though the phylogenetic study published by Lee & Yates (2018) indicated that it was more likely to be a non-crocodilian eusuchian. If the animal was a gavialoid, it was one of the earliest and most basal gavialoids known.

<i>Eosuchus</i> genus of reptiles

Eosuchus is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodilian. It might have been among the most basal of all gavialoids, lying crownward of all other known members of the superfamily, including earlier putative members such as Thoracosaurus and Eothoracosaurus. Fossils have been found from France as well as eastern North America in Maryland, Virginia, and New Jersey. The strata from which specimens have been found date back to the late Paleocene and early Eocene epochs.

<i>Gryposuchus</i> Extinct genus of gavialoid crocodilian

Gryposuchus is an extinct genus of gavialoid crocodilian. It is the type genus of the subfamily Gryposuchinae. Fossils have been found from Argentina, Colombia, Venezuela, Brazil and the Peruvian Amazon. The genus existed from the Middle Miocene to Late Pleistocene. One recently described species, G. croizati, grew to an estimated length of 10 metres (33 ft).

<i>Kentisuchus</i> genus of reptiles

Kentisuchus is an extinct genus of tomistomine crocodylian. It is considered one of the most basal members of the subfamily. Fossils have been found from England and France that date back to the early Eocene. The genus has also been recorded from Ukraine, but it unclear whether specimens from Ukraine are referable to Kentisuchus.

Orthogenysuchus is an extinct genus of caimanine alligatorids. Fossils have been found from the Wasatch Beds of the Willwood Formation of Wyoming, deposited during the early Eocene. The type species is O. olseni. The holotype, known as AMNH 5178, is the only known specimen belonging to the genus and consists of a skull lacking the lower jaws. The braincase is filled in by the matrix and most of the suture lines between bones are indiscernible, making comparisons with other eusuchian material difficult.

Phosphatosaurus is an extinct genus of dyrosaurid crocodylomorph. It existed during the early Eocene, with fossils having been found from North Africa in Tunisia and Mali. Named in 1955, Phosphatosaurus is a monotypic genus; the type species is P. gavialoides. A specimen has been discovered from Niger, but it cannot be classified at the species level.

Prodiplocynodon is an extinct genus of basal crocodyloid crocodylian. It is the only crocodyloid known from the Cretaceous and existed during the Maastrichtian stage. The only species of Prodiplocynodon is the type species P. langi from the Lance Formation of Wyoming, known only from a single holotype skull lacking the lower jaw.

<i>Stangerochampsa</i> genus of large reptiles

Stangerochampsa is an extinct genus of globidontan alligatoroid, possibly an alligatorine or a stem-caiman, from the Late Cretaceous of Alberta. It is based on RTMP.86.61.1, a skull, partial lower jaws, and partial postcranial skeleton discovered in the late Campanian–early Maastrichtian-age Horseshoe Canyon Formation. Stangerochampsa was described in 1996 by Wu and colleagues. The type species is S. mccabei. The generic name honors the Stanger family, the owners of the ranch where the specimen was found, and the species name honors James Ross McCabe, who discovered, collected, and prepared it. Stangerochampsa is described as "small to medium–sized"; the type skull is 20.03 centimetres (7.89 in) long from the tip of the snout to the occipital condyle, and is 13.0 centimetres (5.1 in) wide at its greatest, while the thigh bone is 14.2 centimetres (5.6 in) long. It had heterodont dentition, with large crushing teeth at the rear of the jaws.

Tienosuchus is a dubious extinct genus of gavialoid crocodilian. It is known from a single tooth and some postcranial remains collected from Eocene deposits in Hunan, China. It is closely related to the genus Thoracosaurus, and has traditionally been placed in the subfamily Thoracosaurinae. The subfamily is now considered to be a paraphyletic assemblage of basal gavialoids, and therefore not a true clade. Because the fragmentary remains provide little diagnostic value, the genus is now considered a nomen dubium.

<i>Thecachampsa</i> genus of reptiles

Thecachampsa is an extinct genus of tomistomine crocodylian. Fossils have been found from the eastern United States in deposits of late Oliogcene to Miocene age. Those named in the 19th century were distinguished primarily by the shape of their teeth, and have since been combined with T. antiqua. More recently erected species were reassigned from other tomistomine genera, although their assignment to Thecachampsa has since been questioned.

Tomistominae subfamily of reptiles

Tomistominae is a subfamily of crocodylians that includes one living species, the false gharial. Many more extinct species are known, extending the range of the subfamily back to the Eocene epoch. In contrast to the false gharial, which is a freshwater species that lives only in southeast Asia, extinct tomistomines had a global distribution and lived in estuaries and along coastlines.

References

  1. 1 2 Brochu, C. A. (2006). "Osteology and phylogenetic significance of Eosuchus minor (Marsh, 1870) new combination, a longirostrine crocodylian from the Late Paleocene of North America". Journal of Paleontology . 80 (1): 162–186. doi:10.1666/0022-3360(2006)080[0162:OAPSOE]2.0.CO;2.
  2. Michael S. Y. Lee; Adam M. Yates (2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil record". Proceedings of the Royal Society B: Biological Sciences. 285 (1881): 20181071. doi:10.1098/rspb.2018.1071. PMC   6030529 . PMID   30051855.
  3. Page 125; A study of fossil vertebrate types in the Academy of Natural Sciences of Philadelphia: taxonomic, systematic, and historical perspectives Issue 16 of Special Publication Series, Academy of Natural Sciences (Philadelphia, Pa.) By Earle E. Spamer, Edward Daeschler, L. Gay Vostreys-Shapiro. Academy of Natural Sciences, 1995 ISBN   0-910006-51-2 ISBN   978-0-910006-51-4
  4. Brignon, A. (2017). "The collecting of fossil vertebrates in Mont-Aimé (Marne, France) by the Baron de Ponsort (1792–1854)". Bulletin d'Information des Géologues du Bassin de Paris. 54 (3): 20–44.
  5. "Archived copy". Archived from the original on 2012-02-08. Retrieved 2012-02-08.CS1 maint: archived copy as title (link)