''Olivierosuchus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

therocephalia Therocephalia is an extinct suborder of eutheriodont therapsids (mammals and their close relatives) from the Permian and Triassic. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their te ...

therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

s. It is a member of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Akidnognathidae Akidnognathidae is an extinct family of therocephalian therapsids from the Late Permian and Early Triassic of South Africa, Russia and China. The family includes many large-bodied therocephalians that were probably carnivorous, including ''Mosch ...

. Fossils of ''Olivierosuchus'' have been found from the

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a un ...

''Lystrosaurus'' Assemblage Zone in

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. Unlike other akidnognathids such as ''

Moschorhinus ''Moschorhinus'' is an extinct genus of therocephalian in the family Akidnognathidae with only one species: ''M. kitchingi''. It was a carnivorous synapsid which has been found in the Late Permian to Early Triassic of the South African Karoo Supe ...

'', it has a narrow snout and fewer postcanine teeth. As a distinguishing feature, ''Olivierosuchus'' also has a sharp ridge near the

choana The choanae (singular choana), posterior nasal apertures or internal nostrils are two openings found at the back of the nasal passage between the nasal cavity and the throat in tetrapods, including humans and other mammals (as well as crocodilia ...

, an opening in the skull

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sepa ...

. Bumps and projections cover the

pterygoid Pterygoid, from the Greek for 'winglike', may refer to: * Pterygoid bone, a bone of the palate of many vertebrates * Pterygoid processes of the sphenoid bone ** Lateral pterygoid plate ** Medial pterygoid plate * Lateral pterygoid muscle * Medial ...

, a bone that forms part of the palate. ''Olivierosuchus'' was a top predator of the lower ''Lystrosaurus'' Assemblage Zone (LAZ) and lived alongside other large therapsids like ''Moschorhinus''. The high diversity of akidnognathids in the LAZ suggests that the group recovered quickly from the Permian-Triassic extinction event, a mass extinction in which many other therapsid groups disappeared. A burrow cast described in 2010 from the LAZ has been attributed to ''Olivierosuchus'' or a related therocephalian. The burrow is straight and wide and includes an entry ramp and living chamber. Remains of a juvenile ''

Lystrosaurus ''Lystrosaurus'' (; 'shovel lizard'; proper Greek is λίστρον ''lístron'' ‘tool for leveling or smoothing, shovel, spade, hoe’) is an extinct genus of herbivorous dicynodont therapsids from the late Permian and Early Triassic epochs (a ...

dicynodont Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivorous animals with a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typicall ...

were found in the cast, but the individual was likely too small to dig the burrow. It is possible that the burrow was home to an ''Olivierosuchus'' that had stashed the remains of the dicynodont as its prey in the tunnel. Carnivorous

tetrapod Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct theraps ...

s typically create straight burrows and often store food in them, providing evidence for this interpretation of the South African burrow.

References

Akidnognathids Extinct animals of Africa Therocephalia genera {{Paleo-Therapsid-stub