Baurusuchus

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Baurusuchus
Temporal range: Late Cretaceous, Turonian–Santonian
Baurusuchus salgadoensis (MPMA) 1.jpg
Skull of Baurusuchus salgadoensis
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Crocodylomorpha
Suborder: Notosuchia
Branch: Sebecosuchia
Family: Baurusuchidae
Subfamily: Baurusuchinae
Genus: Baurusuchus
Price, 1945
Species
  • B. albertoi Nascimento & Zaher, 2010
  • B. pachechoi Price, 1945 (type)
  • B. salgadoensis Carvalho et al., 2005

Baurusuchus is an extinct genus of baurusuchid mesoeucrocodylian from the Late Cretaceous of Brazil. It was a terrestrial predator and scavenger, about 3.5 to 4 metres (11 to 13 ft) long and 80 to 100 kilograms (180 to 220 lb) in weight.[1] Baurusuchus lived during the Turonian to Santonian stages (90-83.5 million years ago) of the Late Cretaceous Period, in Adamantina Formation, Brazil.[2] It gets its name from the Brazilian Bauru Group ("Bauru crocodile"). It was related to the earlier-named Cynodontosuchus rothi, which was smaller, with weaker dentition.[3] The three species are B. pachechoi,[4] B. salgadoensis (named after General Salgado County in São Paulo, Brazil)[5] and B. albertoi (named after Dr. Alberto Barbosa de Carvalho, Brazilian paleontologist).[2] Its relatives include the similarly sized Stratiotosuchus from the Adamantina Formation, and Pabweshi, from the Pakistani Pab Formation.

Paleoecology[edit]

Life restoration of B. salgadoensis

B. salgadoensis is seen as a terrestrial predator, living in hot and arid climate. The position of the external nares was unsuited for an amphibious lifestyle like in modern crocodilians and the snout and teeth are laterally compressed like in theropods. Both of this supports the terrestrial hypothesis. The hot environment hypothesis is based on the lifestyle of modern crocodilians and the stratigraphy of Baurusuchus. B. salgadoensis was found in fine massive sandstones which are interpreted as a floodplain area in hot and arid climate. Baurusuchus was likely able to dig holes for finding water in dry seasons or, like modern alligators do, for thermoregulation. The occurrence of very complete skeletons in correlated stratigraphic levels supports this. Such a strategy would have made it less water-bound than most modern crocodiles, allowing it to live in more continental climate. The strongly bent pterygoids suggest a powerful bite and that Baurusuchus could close its jaw very quickly. The skull and teeth morphology indicates that the biting strategies of Baurusuchus were similar to a Komodo dragon which include ambushing the prey, biting it and pulling back the serrated, blade-like teeth. Baurusuchus likely played an important role in its ecosystem, competing with the abelisaurids for food.[5]

Phylogeny[edit]

B. albertoi

Baurusuchus is the type genus of the family Baurusuchidae, a family consisting of crocodilians with elongated and laterally compressed skulls.[4] Other members of that family from the Cretaceous of South America include Stratiotosuchus and Cynodontosuchus, but baurusuchids are also known from the Cretaceous of Asia (Pakistan) and the Tertiary of Europe.[5]

A study in 2011 erected a new subfamily called Baurusuchinae. Seven diagnostic features for the group were described which include the moderate size and the broad frontals. The family only includes Stratiotosuchus and Baurusuchus, making Stratiotosuchus Baurusuchus' closest relative so far.[6]

Sources[edit]

  • In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods by Nicholas C. Fraser and Hans-Dieter Sues
  • The Osteology of the Reptiles by Alfred Sherwood Romer

References[edit]

  1. ^ https://sites.google.com/site/paleofilescom/baurusuchus
  2. ^ a b Paulo Miranda Nascimento and Hussam Zaher (2010). "A new species of Baurusuchus (Crocodyliformes, Mesoeucrocodylia) from the Upper Cretaceous of Brazil, with the first complete postcranial skeleton described from the family Baurusuchidae". Papeis Avulsos de Zoologia 50 (21): 323‑361. 
  3. ^ Bonaparte, Jose F. (1996). "Cretaceous tetrapods of Argentina". Muncher Geowissenschaften, Abhandlungen 30: 73–130. 
  4. ^ a b Price, L.I. (1945). "A new reptile from the Cretaceous of Brazil". Departamento Nacional da Produção Mineral, Notas preliminares e estudos (Rio de Janeiro) 25: 1–8. 
  5. ^ a b c Carvalho; Campos, Antonio; de Celso, Arruda; Nobre, Pedro Henrique (2005). "Baurusuchus salgadoensis, a new Crocodylomorpha from the Bauru Basin (Cretaceous), Brazil" (PDF). Gondwana Research (Japan: International Association for Gondwana Research) 8 (1): 11–30. doi:10.1016/S1342-937X(05)70259-8. ISSN 1342-937X. 
  6. ^ Felipe C. Montefeltro, Hans C. E. Larsson, Max C. Lange (2011). "A New Baurusuchid (Crocodyliformes, Mesoeucrocodylia) from the Late Cretaceous of Brazil and the Phylogeny of Baurusuchidae". PLoS ONE 6 (7): 1–26. doi:10.1371/journal.pone.0021916.