Barinasuchus

Barinasuchus (meaning "Barinas crocodile," in reference to where the type material was found) is an extinct genus of sebecid mesoeucrocodylian. Its fossils have been found in middle Eocene-age rocks of the Divisadero Largo Formation of Argentina, middle Miocene-age rocks of the Ipururo Formation of Peru, and middle Miocene-age rocks of the Parángula Formation of Venezuela.[1]

Barinasuchus
Holotype fossil of Barinasuchus arveloi
Scientific classification Edit this classification
Domain:Eukaryota
Kingdom:Animalia
Phylum:Chordata
Class:Reptilia
Clade:Archosauria
Clade:Pseudosuchia
Clade:Crocodylomorpha
Clade:Crocodyliformes
Clade:Notosuchia
Clade:Sebecosuchia
Clade:Sebecia
Family:Sebecidae
Genus:Barinasuchus
Paolillo and Linares, 2007
Type species
Barinasuchus arveloi
Paolillo and Linares, 2007

Description

Barinasuchus was described in 2007 by Alfredo Paolillo and Omar Linares.[2] The holotype comes from the rocks of the Parángula Formation, located in Barinas, Venezuela and consists of an incomplete, articulated skull. Like other sebecosuchians, it was a terrestrial carnivore equipped with ziphodont teeth, remarkably similar to those of theropods, which are compressed laterally, curved facing backwards, and with serrated borders. This dentition made it a formidable predator.

Reconstructed skull of Barinasuchus.

The preserved parts of the holotype consist of a skull that is 70 centimeters in length and 40 centimeters in height. Based on this, it is estimated that the total skull length was between 95 and 115 centimeters.[3] The total length of the animal is estimated to be close to 6 m (20 ft) based on more complete sebecosuchians like Stratiotosuchus,[3] making Barinasuchus the largest known sebecid. Without more complete remains, it is difficult to estimate its possible weight; however, based in the lengths of Stratiosuchus mexhechti and Crocodylus porosus, it has been estimated that Barinasuchus weighed around 1,610 and 1,720 kilograms respectively. This implies a superior weight than any of the large carnivoran mammals, and even considering a margin error of 50%, would still make it larger than any terrestrial mammalian predator of the Cenozoic.[3]

Fossils of the same age found in Peru previously assigned to Sebecus cf. huilensis were assigned to the type species, B. arveloi.[2]

Classification

In 2014, Diego Pol and his colleagues made a phylogenetic analysis, integrating many of the new genera and species found in the early 2010s. Compiling various phylogenetic studies in order to make a matrix that included 109 genera of Crocodyliforms, of which 412 morphological characteristics were studied. Notosuchia according to Diego Pol et al. includes 45 genera and 54 species.[4] In their cladogram, Barinasuchus is classified as a Sebecosuchian belonging to the family Sebecidae, close to the Lorosuchus genus and forms a sister taxon to the genera of Ayllusuchus and Bretesuchus, indicating that Barinasuchus belonged to a distant, basal lineage within the family.[4]

Hypothetical appearance and size of Barinasuchus arveloi

Cladogram based on the study done by Kellner et al. (2014), showing the position of Barinasuchus within Sebecosuchia.[5]

See also

References