''Parvosuchus'' (meaning "small crocodile") is an
extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
genus of
gracilisuchid
Gracilisuchidae is an extinct family of suchian archosaurs known from the early Middle Triassic to the early Late Triassic (Anisian – early Carnian) of China, Argentina, and Brazil.
Distribution
Currently, the oldest known gracilisuchid is '' ...
pseudosuchians from the
Middle
Middle or The Middle may refer to:
* Centre (geometry), the point equally distant from the outer limits.
Places
* Middle (sheading), a subdivision of the Isle of Man
* Middle Bay (disambiguation)
* Middle Brook (disambiguation)
* Middle Creek ...
–
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch a ...
Santa Maria Formation
The Santa Maria Formation is a sedimentary rock formation found in Rio Grande do Sul, Brazil. It is primarily Carnian in age (Late Triassic), and is notable for its fossils of cynodonts, " rauisuchian" pseudosuchians, and early dinosaurs and othe ...
(
Paraná Basin
The Paraná Basin (, ) is a large cratonic sedimentary basin situated in the central-eastern part of South America. About 75% of its areal distribution occurs in Brazil, from Mato Grosso to Rio Grande do Sul states. The remainder area is distribu ...
) of Brazil. The genus contains a
single species, ''P. aurelioi'', known from a cranium and partial skeleton.
Discovery and naming

The ''Parvosuchus''
holotype
A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...
specimen, CAPPA/
UFSM
The Federal University of Santa Maria (, UFSM) is a Brazilian public university located in Santa Maria, in the state of Rio Grande do Sul, funded by the federal government of Brazil. It was founded in 1960, by Professor José Mariano da Rocha ...
0412, was discovered at the Linha Várzea 2 site in the Pinheiros-Chiniquá Sequence, which belongs to the
Santa Maria Formation
The Santa Maria Formation is a sedimentary rock formation found in Rio Grande do Sul, Brazil. It is primarily Carnian in age (Late Triassic), and is notable for its fossils of cynodonts, " rauisuchian" pseudosuchians, and early dinosaurs and othe ...
of the Santa Maria Supersequence (
Paraná Basin
The Paraná Basin (, ) is a large cratonic sedimentary basin situated in the central-eastern part of South America. About 75% of its areal distribution occurs in Brazil, from Mato Grosso to Rio Grande do Sul states. The remainder area is distribu ...
) in
Paraíso do Sul municipality of
Rio Grande do Sul
Rio Grande do Sul (, ; ; "Great River of the South") is a Federative units of Brazil, state in the South Region, Brazil, southern region of Brazil. It is the Federative units of Brazil#List, fifth-most populous state and the List of Brazilian s ...
state, Brazil. This locality represents the ''
Dinodontosaurus
''Dinodontosaurus'' (meaning "terrible-toothed lizard") is a genus of dicynodont therapsid. It was medium to large dicynodont of the Triassic (with skull up to long) and had a beak corneum. It lived in the Middle Triassic but disappeared in the ...
''
Assemblage Zone
In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa, as opposed to a lithostratigraphic unit which is defined by the lithological properties ...
. The specimen consists of a largely
articulated
An articulated vehicle is a vehicle which has a permanent or semi-permanent coupling in its construction. This coupling works as a large pivot joint, allowing it to bend and turn more sharply. There are many kinds, from heavy equipment to buse ...
skeleton, including the skull and lower jaws, the last 11
dorsal vertebrae
In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebra (anatomy), vertebrae of intermediate size between the ce ...
, two
sacral vertebrae
The sacrum (: sacra or sacrums), in human anatomy, is a triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30.
The sacrum situates at the upper, back part of the pelvic cavity, ...
, a
pelvic girdle
The hip bone (os coxae, innominate bone, pelvic bone or coxal bone) is a large flat bone, constricted in the center and expanded above and below. In some vertebrates (including humans before puberty) it is composed of three parts: the Ilium (bone) ...
, part of the right
femur
The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg.
The Femo ...
, and a partial left hindlimb (comprising pieces of the femur,
tibia
The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...
,
fibula
The fibula (: fibulae or fibulas) or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. ...
, and
calcaneum
In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel; : calcanei or calcanea) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is t ...
).
In 2024, Rodrigo T. Müller
described ''Parvosuchus aurelioi'' as a new genus and species of gracilisuchid pseudosuchians based on these fossil remains. The
generic name, ''Parvosuchus'', combines "parvus", a
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
word meaning "small", with "suchus", a
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
word meaning "crocodile" (''
σοῦχος'', after
Sobek
Sobek (), also known as Suchus (), was an ancient Egyptian deities, ancient Egyptian deity with a complex and elastic history and nature. He is associated with the Nile crocodile and is often represented as a crocodile-headed humanoid, if not a ...
, the crocodile-headed
ancient Egyptian deity
Ancient Egyptian deities are the gods and goddesses worshipped in ancient Egypt. The beliefs and rituals surrounding these gods formed the core of ancient Egyptian religion, which emerged sometime in prehistory. Deities represented natural for ...
). The
specific name Specific name may refer to:
* in Database management systems, a system-assigned name that is unique within a particular database
In taxonomy, either of these two meanings, each with its own set of rules:
* Specific name (botany), the two-part (bino ...
, ''aurelioi'', honors Pedro L. P. Aurélio, the discoverer of the holotype.
Description
The skull of ''Parvosuchus'' is long. Based on its fossil remains and those of more complete relatives, its body length is estimated at . Its teeth are blade-like and elongated, a feature indicative of predatory behavior and carnivorous habits.
Classification
In his
phylogenetic analyses
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as Computational phylogenetics, phylogenetic inference. It infers the relationship among organ ...
, Müller (2024) recovered ''Parvosuchus'' in a clade with ''
Maehary
''Maehary'' (meaning "one who looks to the sky" in Guarani language, Guaraní) is an extinct genus of probable gracilisuchid pseudosuchian archosaurs from the Late Triassic (Norian) Caturrita Formation of Rio Grande do Sul, Brazil. The genus con ...
'' (which was originally identified as an early
pterosauromorph) and ''
Gracilisuchus
''Gracilisuchus'' (meaning "slender crocodile") is an extinct genus of tiny pseudosuchian (a group which includes the ancestors of crocodilians) from the Late Triassic of Argentina. It contains a single species, ''G. stipanicicorum'', which is pl ...
'' within the
Gracilisuchidae. These results are displayed in the
cladogram
A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...
below:
References
{{Taxonbar, from1=Q126750949, from2=Q126750999
Gracilisuchidae
Triassic reptiles of South America
Monotypic prehistoric reptile genera
Fossils of Brazil
Triassic Brazil
Santa Maria Formation
Fossil taxa described in 2024
Taxa named by Rodrigo T. Müller