''Kwatisuchus'' (from the Tupi ''kwa 'tim'' for 'pointy nose' and the Greek ''suchus'' for crocodile) is a genus of benthosuchid
temnospondyl
Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order (biology), order of small to giant tetrapods—often considered Labyrinth ...
amphibian
Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...
from
Early Triassic
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...
deposits of
Brazil
Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...
. It is represented by the type species, ''Kwatisuchus rosai'', which was named for one specimen collected from the Granja Palmeiras site in
Rosário do Sul
Rosário do Sul is a Brazilian municipality in the southwestern part of the state of Rio Grande do Sul. The population is 39,314 (2020 est.) in an area of 4,369.65 km2. Its elevation is 151 m. It is located 385 km west of the state ...
, Brazil. This is the only definitive occurrence of benthosuchids in
Gondwana
Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...
; other benthosuchids such as ''
Benthosuchus
''Benthosuchus'' (meaning "deep water crocodile") is an extinct genus of temnospondyli, temnospondyl amphibian from the Early Triassic of Russia. It was primarily aquatic, living in rivers and lakes. Multiple species are known, with the largest ...
'' are known mainly from Russia.
Description
The type and only species, ''K. rosai'', is diagnosed by a combination of differential features of the skull roof and palate separating it from other benthosuchids and several autapomorphies: 1) anterior margin of the vomers well-developed anterolaterally but not anteromedially and with rudimentary medial spike-like projections; 2) weak inflection of the supraorbital sensory groove on the nasal; and 3) straight nasal-lacrimal suture. As the holotype consists only of a partial snout, other skeletal regions cannot be assessed in ''K. rosai''. Despite its fragmentary nature, a combination of various features such as a heart-shaped anterior palatal vacuity and a V-shaped row of transvomerine teeth support benthosuchid affinities.
Discovery and naming
The holotype and only known specimen, an incomplete snout, was collected from the Granja Palmeiras site in
Rosário do Sul
Rosário do Sul is a Brazilian municipality in the southwestern part of the state of Rio Grande do Sul. The population is 39,314 (2020 est.) in an area of 4,369.65 km2. Its elevation is 151 m. It is located 385 km west of the state ...
. This site preserves outcrops of the
Sanga do Cabral Formation
The Sanga do Cabral Formation is an Early Triassic sedimentary rock formation found in Rio Grande do Sul, Brazil.