Peirosaurus Temporal range: Late Cretaceous, | |
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Peirosaurus (top left) | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauria |
Clade: | Pseudosuchia |
Clade: | Crocodylomorpha |
Clade: | Crocodyliformes |
Suborder: | † Notosuchia |
Clade: | † Sebecosuchia |
Clade: | † Sebecia |
Family: | † Peirosauridae |
Genus: | † Peirosaurus Price, 1955 |
Type species | |
†Peirosaurus torminni Price, 1955 |
Peirosaurus is an extinct genus of peirosaurid crocodylomorph known from the Late Cretaceous period (late Maastrichtian stage) of Minas Gerais, southern Brazil. It contains a single species, Peirosaurus torminni. It is the type genus of the family Peirosauridae.
Peirosaurus is known from the holotype DGM 433-R, fragmentary skull (left premaxilla bearing five teeth, isolated maxillary and dentary teeth and left palpebral bone) and partial postcranial skeleton including radius, ulna, left pubis and ischium, some presacral and a single caudal vertebrae, ribs, haemal arches and dermal plates. It was collected by Llewellyn Ivor Price in 1947-1949 at the Price Quarry 3, Peirópolis Site near Uberaba, in the Serra da Galga Formation (Bauru Group), [1] [2] dating to the late Maastrichtian stage of the Late Cretaceous, about 68-66 million years ago. [3]
A partial skull and several postcranial elements such as vertebrae and dermal plates from the Bajo de la Carpa Formation [4] in Argentina and another partial skull and several unprepared postcranial elements from the Anacleto Formation, Argentina, were assigned to Peirosaurus by Gasparini, Chiappe and Fernandez (1991) and Praderio, Martinelli and Candeiro (2008), respectively. However, more recently Agustín G. Martinelli, Joseph J.W. Sertich, Alberto C. Garrido and Ángel M. Praderio concluded that the traits which used to unite the holotype (from Brazil) and the referred material from Argentina are shared with other peirosaurids and some other mesoeucrocodylians. They reassigned the Argentinian specimens to a new genus, Gasparinisuchus , and although overlapping materials between the genera are limited to the premaxilla and the dentition, Gasparinisuchus can be differentiated from Peirosaurus on the basis of its broad, rounded rostrum, anteroposteriorly short premaxilla, reduced perinareal fossa, and short premaxillary interdental spaces. Hence, Peirosaurus is known only from its holotype. [5]
Peirosaurus has a ziphodont dentition that is somewhat heterodont, with conical premaxillary teeth and serrated maxillary and posterior mandibular teeth. The rostrum is laterally compressed with a grove between the maxilla and premaxilla to accommodate for an enlarged mandibular tooth. A maxillary wedge-like anterior process is also present. The external nares face slightly forward and anteriorly protrude. The dorsal osteoderms are thin and sculptured with low longitudinal keels while the abdominal ones are smaller and lack keels.
Peirosaurus shares a number of features with the closely related genus Uberabasuchus , found from a nearby locality in Uberaba. These include a similar tooth size pattern and the large maxillary anterior process. These genera were differentiated from each other as the rostrum of Uberabasuchus is more compressed than that of Peirosaurus, which is relatively broad. [6] However, the rostrum wasn't preserved in the holotype of Peirosaurus. The removal of MOZ 1750 PV (which preserved the rostrum) from the genus Peirosaurus suggests a possible synonymy between Peirosaurus and Uberabasuchus. [5]
Though many of the features of the premaxilla and dentition of Peirosaurus are widespread among peirosaurids and many mesoeucrocodylians, several are shared exclusively with Uberabasuchus. Among these features some are not observed in other peirosaurids. These include the relatively long anteroposterior facial length of the premaxilla, the elongate and strongly anteromedially directed dorsomedial process of the premaxilla, and the sharply defined and elevated margin of the perinarial fossa. There are differences between the two taxa such as differences in the relative thickness of dorsal osteoderms and the absence of a denticulate mesial carina on the first premaxillary tooth in Peirosaurus, but not in Uberabasuchus. However, these characters are considered to be minor and their taxonomic value may be individually variable. As postcranial materials of both Peirosaurus and Uberabasuchus are known but are not yet formally described, they are tentatively considered to be valid taxa. [5]
Doratodon is an extinct genus of Late Cretaceous crocodylomorph that may have been a member of the Sebecosuchia. Doratodon was a relatively small animal with ziphodont teeth, meaning the teeth had flattened sides and serrated edges. Two species of Doratodon are known to science: D. carcharidens from Austria and Hungary, the type species; and D. ibericus from Spain. Teeth similar to those of Doratodon are also known from Italy and Romania, though they cannot be confidently assigned to this genus.
The Bajo de la Carpa Formation is a geologic formation of the Neuquén Basin that crops out in northern Patagonia, in the provinces of Río Negro and Neuquén, Argentina. It is the oldest of two formations belonging to the Río Colorado Subgroup within the Neuquén Group. Formerly, that subgroup was treated as a formation, and the Bajo de la Carpa Formation was known as the Bajo de la Carpa Member.
Simosuchus is an extinct genus of notosuchian crocodylomorphs from the Late Cretaceous of Madagascar. It is named for its unusually short skull. Fully grown individuals were about 0.75 metres (2.5 ft) in length. The type species is Simosuchus clarki, found from the Maevarano Formation in Mahajanga Province, although one isolated multicuspid tooth of this genus was discovered in Kallamedu Formation of India.
Mahajangasuchus is an extinct genus of crocodyliform which had blunt, conical teeth. The type species, M. insignis, lived during the Late Cretaceous; its fossils have been found in the Maevarano Formation in northern Madagascar. It was a fairly large predator, measuring up to 4 metres (13 ft) long.
Peirosauridae is a Gondwanan family of mesoeucrocodylians that lived during the Cretaceous period. It was a clade of terrestrial crocodyliforms that evolved a rather dog-like skull, and were terrestrial carnivores. It was phylogenetically defined in 2004 as the most recent common ancestor of Peirosaurus and Lomasuchinae and all of its descendants. Lomasuchinae is a subfamily of peirosaurids that includes the genus Lomasuchus.
Wargosuchus is an extinct genus of baurusuchid mesoeucrocodylian from the Late Cretaceous of Argentina. It is known from a fragmentary skull from the Santonian-age Bajo de la Carpa Formation of the Neuquén Group, found in the vicinity of Neuquén, Neuquén Province, and was described by Agustín Martinelli and Diego Pais in 2008. The type species, and so far the only species, is Wargosuchus australis.
Langstonia is an extinct genus of notosuchian crocodylomorph of the family Sebecidae. It lived in the middle Miocene, in the "Monkey Beds" of the Colombian Villavieja Formation. Langstonia was named in 2007 by Alfredo Paolillo and Omar Linares for fossils originally described by Langston in 1965 as Sebecus huilensis. Thus, the type species is L. huilensis.
Pabwehshi is an extinct genus of mesoeucrocodylian. It is based on GSP-UM 2000, a partial snout and corresponding lower jaw elements, with another snout assigned to it. These specimens were found in Maastrichtian-age Upper Cretaceous rocks of the Vitakri and Pab Formations in Balochistan, Pakistan, and represent the first diagnostic crocodyliform fossils from Cretaceous rocks of South Asia. Pabwehshi had serrated interlocking teeth in its snout that formed a "zig-zag" cutting edge. Pabwehshi was named in 2001 by Jeffrey A. Wilson and colleagues. The type species is P. pakistanensis, in reference to the nation where it was found. It was traditionally classified as a baurusuchid closely related to Cynodontosuchus and Baurusuchus. Larsson and Sues (2007) found close affinity between Pabwehshi and the Peirosauridae within Sebecia. Montefeltro et al.Pabwehshi has a sagittal torus on its maxillary palatal shelves – a character that is absent in baurusuchids – but they did not include Pabwehshi in their phylogenetic analysis.
Trematochampsidae is an extinct family of mesoeucrocodylian crocodylomorphs. Fossils are present from Madagascar, Morocco, Niger, Argentina, and Brazil. Possible trematochampsids have been found from Spain and France, but classification past the family level is indeterminant. The trematochampsids first appeared during the Barremian stage of the Early Cretaceous and became extinct during the late Maastrichtian stage of the Late Cretaceous.
Lomasuchus is an extinct genus of peirosaurid notosuchian known from the Late Cretaceous of Neuquén Province, western central Argentina. It contains a single species, Lomasuchus palpebrosus.
The Uberaba Formation is a Campanian geologic formation belonging to the Bauru Group of the Bauru Sub-basin, Paraná Basin located in Minas Gerais state of southeastern Brazil. The Uberaba Formation, intercalating the fossiliferous older Adamantina and younger Marília Formation, comprises limestones, sandstones, and conglomerates, often cemented by calcite with volcaniclastic sediments. The formation interfingers with the Adamantina Formation.
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.
Pepesuchus is an extinct genus of carnivorous metasuchian from the Late Cretaceous period. It is a peirosaurid which lived during the Campanian and Maastrichtian stages of the Late Cretaceous in what is now state of São Paulo, Brazil. It was a semiaquatic crocodylomorph.
Campinasuchus is an extinct genus of baurusuchid mesoeucrocodylian from Minas Gerais State of Brazil.
Eremiasaurus is a genus of mosasaurs, an extinct group of marine reptiles. It lived during the Maastrichtian stage of the Late Cretaceous in what is now North Africa. Only one species is known, E. heterodontus, described in 2012 from two remarkably complete fossil specimens discovered in the Ouled Abdoun Basin, Morocco. This site is known to have delivered a significant number of other related mosasaurs.
Labidiosuchus is an extinct genus of notosuchian mesoeucrocodylian from Minas Gerais State, southeastern Brazil. Labidiosuchus had a very bizarre dentition and its lower jaw had a Y-shaped outline.
Gasparinisuchus is an extinct genus of peirosaurid notosuchian known from the Late Cretaceous of Neuquén and Mendoza Provinces, western central Argentina. It contains a single species, Gasparinisuchus peirosauroides.
Rukwasuchus is an extinct genus of peirosaurid mesoeucrocodylian known from the middle Cretaceous Galula Formation of southwestern Tanzania. It contains a single species, Rukwasuchus yajabalijekundu.
Kyhytysuka is an extinct genus of ophthalmosaurian ichthyosaur from Early Cretaceous Colombia. The animal was previously assigned to the genus Platypterygius, but given its own genus in 2021. Kyhytysuka was a mid-sized ophthalmosaurian with heterodont dentition and several adaptations suggesting that it was a macropredatory vertebrate hunter living in shallow waters. It contains a single species, Kyhytysuka sachicarum.
Monquirasaurus is an extinct genus of giant short-necked pliosaurs who lived during the Early Cretaceous (Aptian) in what is now Colombia. One species is known, M. boyacensis, described in 2021 from an almost complete fossil skeleton, discovered in 1977 in the town of Villa de Leyva, located in Boyacá. Published descriptions of the holotype specimen estimate that it should reach a total size approaching 8 m (26 ft) in length, making Monquirasaurus a large representative of the pliosaurids.