Protosuchia

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Protosuchia
Temporal range: Late Triassic - Late Cretaceous
Protosuchus richardsoni AMNH 3024 cast.jpg
A skeleton of Protosuchus richardsoni in the American Museum of Natural History
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Clade: Pseudosuchia
Clade: Crocodylomorpha
Clade: Crocodyliformes
Informal group: Protosuchia
Mook, 1934
Subgroups

See text.

Protosuchia is a group of extinct Mesozoic crocodyliforms. They were small in size (~1 meter in length) and terrestrial. In phylogenetic terms, Protosuchia is considered an informal group because it is a grade of basal crocodyliforms, not a true clade.

Classification

Recent phylogenetic analyses have not supported Protosuchia as a natural group. However, two studies found a clade of Late Triassic-Early Jurassic animals: [1] [2]

Both of these studies also found a clade more closely related to Hsisosuchus and Mesoeucrocodylia consisting of Late Jurassic-Late Cretaceous genera: [1] [2]

However, other possible protosuchians from the Late Cretaceous of China-Mongolia, the Gobiosuchidae ( Gobiosuchus and Zaraasuchus ), have been found to be either intermediate between these two clades, [1] or members of the Sichuanosuchus clade. [2] There is also another family of Late Jurassic-Late Cretaceous genera, the Shartegosuchidae (e.g. Kyasuchus , Shartegosuchus and Nominosuchus ).

Below is a cladogram from Fiorelli and Calvo (2007). [2] Protosuchians are marked by the green bracket.

Crocodylomorpha  

Terrestrisuchus

Dibothrosuchus

  Crocodyliformes  
  Gobiosuchidae  

Gobiosuchus

Zaraasuchus

Orthosuchus

  Protosuchidae  

Protosuchus

Hemiprotosuchus

"Kayenta Form"

Edentosuchus

  Mesoeucrocodylia  

"Fruitachampsa"

Zosuchus

Sichuanosuchus

Shantungosuchus

Neuquensuchus

Hsisosuchus

  Metasuchia  

Neosuchia

Peirosauridae

Notosuchia

Protosuchians

Related Research Articles

<span class="mw-page-title-main">Mesoeucrocodylia</span> Clade of reptiles

Mesoeucrocodylia is the clade that includes Eusuchia and crocodyliforms formerly placed in the paraphyletic group Mesosuchia. The group appeared during the Early Jurassic, and continues to the present day.

<i>Sichuanosuchus</i> Extinct genus of reptiles

Sichuanosuchus is an extinct genus of crocodyliform from the Late Jurassic and possibly Early Cretaceous of China.

<span class="mw-page-title-main">Notosuchia</span> Extinct suborder of reptiles

Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group ; if Sebecosuchia is included within Notosuchia its existence is pushed into the Middle Miocene, about 11 million years ago. Fossils have been found from South America, Africa, Asia, and Europe. Notosuchia was a clade of terrestrial crocodilians that evolved a range of feeding behaviours, including herbivory (Chimaerasuchus), omnivory (Simosuchus), and terrestrial hypercarnivory (Baurusuchus). It included many members with highly derived traits unusual for crocodylomorphs, including mammal-like teeth, flexible bands of shield-like body armor similar to those of armadillos (Armadillosuchus), and possibly fleshy cheeks and pig-like snouts (Notosuchus). The suborder was first named in 1971 by Zulma Gasparini and has since undergone many phylogenetic revisions.

Neuquensuchus is an extinct genus of crocodyliform from the Santonian-age Upper Cretaceous Bajo de la Carpa Formation of Neuquén Province, Argentina. The known remains were discovered on the campus of Universidad Nacional del Comahue in the city of Neuquén. Neuquensuchus was named by Lucas E. Fiorelli and Jorge O. Calvo in a publication dated to 2007, but which became available in 2008. The type species is N. universitas, in recognition of its discovery locality. Unlike the great majority of crocodyliforms, its shin was longer than its thigh, suggesting it had some running ability.

<span class="mw-page-title-main">Baurusuchidae</span> Extinct family of reptiles

Baurusuchidae is a Gondwanan family of mesoeucrocodylians that lived during the Late Cretaceous. It is a group of terrestrial hypercarnivorous crocodilians from South America and possibly Pakistan. Baurusuchidae has been, in accordance with the PhyloCode, officially defined as the least inclusive clade containing Cynodontosuchus rothi, Pissarrachampsa sera, and Baurusuchus pachecoi. Baurusuchids have been placed in the suborder Baurusuchia, and two subfamilies have been proposed: Baurusuchinae and Pissarrachampsinae.

Edentosuchus is a genus of protosuchian crocodyliform. It is known from fossils found in rocks of the Early Cretaceous-age Tugulu Group from the Junggar Basin, Xinjiang, China. Two partial skulls and several neck vertebrae are known to date. An articulated partial postcranial skeleton may also belong to this genus, but there is no overlapping material between it and known Edentosuchus specimens.

<i>Fruitachampsa</i> Extinct genus of reptiles

Fruitachampsa is a genus of shartegosuchid crocodyliform from the Upper Jurassic Morrison Formation of Colorado. It is known from multiple specimens that show it to have been a relatively long-limbed terrestrial quadrupedal predator less than 1 metre (3.3 ft) long, with a short face and a prominent pair of canine-like teeth in the lower jaw. Before it was formally described in 2011, it was also known as the "Fruita form". Its type species is F. callisoni.

Eopneumatosuchus is an extinct genus of basal crocodyliform. Fossils have been found from two localities within the Kayenta Formation of Arizona. Both localities are around 20 miles southeast of the Grand Canyon and in close proximity to one another. The localities probably date back to the Early Jurassic, most likely during the Sinemurian stage.

The binomial name “Hadongsuchus acerdentis” refers to the skull remain of an extinct "protosuchian" crocodyliform from the Hasandong Formation of Hadong, South Korea.

<span class="mw-page-title-main">Crocodyliformes</span> Clade of reptiles

Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the only pseudosuchians to survive the K-Pg extinction event.

Kyasuchus is an extinct genus of shartegosuchid crocodyliform. Fossils have been found from the Ilek Formation outcropping in the Kemerovo Oblast of Russia, deposited during the Aptian and Albian stages of the Early Cretaceous. The localities from which specimens of this genus have been found have also yielded many other vertebrate remains such as those of palaeonisciform fishes, turtles, various lizards, troodontids, triconodonts, the ceratopsian Psittacosaurus, and the protosuchian-grade crocodylomorph Tagarosuchus.

Microchampsa is an extinct genus of protosuchian crocodyliform that existed during the Early Jurassic. Fossils have been found from stratum 6 of the Dahuangtian locality, an outcrop of the Lower Red Beds of the Lufeng Formation in Yunnan, China.

<span class="mw-page-title-main">Paralligatoridae</span> Extinct family of reptiles

Paralligatoridae is an extinct family of neosuchian crocodyliforms that existed during the Jurassic and Cretaceous periods. It includes the genera Paralligator, Brillanceausuchus, Kansajsuchus, Shamosuchus, Scolomastax, Sabresuchus, Rugosuchus, Batrachomimus and Wannchampsus, as well as the yet-unnamed "Glen Rose form".

<i>Platyognathus</i> Extinct genus of reptiles

Platyognathus is an extinct genus of protosuchian crocodyliform. Fossils are known from the Early Jurassic Lower Lufeng Formation in Yunnan, China and belong to the type and only species, P. hsui.

Shartegosuchidae is an extinct family of Late Jurassic and Early Cretaceous crocodylomorphs. The family is named after the Late Jurassic Shar Teeg Beds in southwestern Mongolia, from which most shartegosuchid remains have been found. Five genera are currently assigned to Shartegosuchidae: Shartegosuchus, Nominosuchus, Kyasuchus, Adzhosuchus, and Fruitachampsa. Shartegosuchus, Nominosuchus, and Adzhosuchus all come from Shar Teeg, while Kyasuchus is known from the Early Cretaceous of Russia. Fruitachampsa is known from the Late Jurassic Morrison Formation of the western United States.

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

Sebecia is an extinct clade of mesoeucrocodylian crocodyliforms that includes peirosaurids and sebecids. It was first constructed in 2007 to include Hamadasuchus, Peirosauridae, and Sebecus. It was initially considered to be the sister taxon of the clade Neosuchia, which includes living crocodilians, although some later studies have placed it within Neosuchia as a basal clade. Sebecians were terrestrial crocodyliforms characterized by their deep snouts and ziphodont dentition. They first appeared in the Late Cretaceous, survived the Cretaceous–Paleogene extinction event, and became extinct in the Miocene epoch.

Sebecosuchia is an extinct group of mesoeucrocodylian crocodyliforms that includes the families Sebecidae and Baurusuchidae. The group was long thought to have first appeared in the Late Cretaceous with the baurusuchids and become extinct in the Miocene with the last sebecids, but Razanandrongobe pushes the origin of Sebecosuchia to the Middle Jurassic. Fossils have been found primarily from South America but have also been found in Europe, North Africa, Madagascar, and the Indian subcontinent.

Shantungosuchus is an extinct genus of Early Cretaceous crocodyliform found in China. It includes three species: Shantungosuchus chuhsienensis and S. brachycephalus, which were both described by Yang Zhongjian – usually referred to as "Young" – in 1961 and 1982, and S. hangjinensis, which was described by Xiao-Chun Wu et al in 1994. S. chuhsienensis is the type for this genus.

Tagarosuchus is an extinct genus of Early Cretaceous protosuchian-grade crocodyliform. Fossils of Tagarosuchus have been found from southern Siberia, including a nearly complete skull found near the village of Shestakovo in Kemerovo Oblast. Tagarosuchus was named in 1999, with the type species being T. kulemzini. Remains have been recovered from the Aptian-Albian Ilek Formation.

Paluxysuchus is an extinct genus of neosuchian crocodyliform known from the Early Cretaceous Twin Mountains Formation of north-central Texas. It contains a single species, Paluxysuchus newmani. Paluxysuchus is one of three crocodyliforms known from the Early Cretaceous of Texas, the others being Pachycheilosuchus and an unnamed species referred to as the "Glen Rose Form". Paluxysuchus has a long, flat skull that is probably transitional between the long and narrow skulls of many early neosuchians and the short and flat skulls of later neosuchians.

References

  1. 1 2 3 Pol D, Ji S-a, Clark JM, Chiappe LM. 2004. Basal crocodyliforms from the Lower Cretaceous Tugulu Group (Xinjiang, China), and the phylogenetic position of Edentosuchus. Cretaceous Research25: 603-622.
  2. 1 2 3 4 Fiorelli LE, Calvo JO. 2007. The first "protosuchian" (Archosauria: Crocodyliformes) from the Cretaceous (Santonian) of Gondwana. Arquivos do Museu Nacional, Rio de Janeiro65 (4): 417-459.