Rhadinosuchidae is an extinct family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of archosauriforms. It includes the proterochampsia

Proterochampsia

Proterochampsia is a clade of early archosauriform reptiles from the Triassic period. It includes the genera Proterochampsa, Cerritosaurus, Chanaresuchus, Gualosuchus, Rhadinosuchus, and Tropidosuchus...

ns Gualosuchus, Chanaresuchus

Chanaresuchus

Chanaresuchus is an extinct genus of proterochampsian archosauriform. It was of modest size for a proterochampsian, being on average just over a meter in length. Fossils have been found from the Chañares Formation in La Rioja Provence, Argentina, dating back to the Ladinian stage of the Middle...

, and Rhadinosuchus

Rhadinosuchus

Rhadinosuchus is an extinct genus of proterochampsian archosauriform reptile from the Late Triassic. It is known only from the type species Rhadinosuchus gracilis. It is reposited in Munich. The fossil has the form of an incomplete skull and fragments of post-cranial material...

, all of which are from the Middle

Middle Triassic

In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between 245 ± 1.5 Ma and 228 ± 2 Ma...

 and Late Triassic

Late Triassic

The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...

 of Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

. Rhadinosuchus, the type genus

Type genus

In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...

 of the family, was originally described as a rauisuchia

Rauisuchia

Rauisuchia is a group of predatory and mostly large Triassic archosaurs. As a clade, Rauisuchia includes these Triassic forms and all crocodylomorphs, which are descendants of Triassic rauisuchians. The group in its traditional sense is paraphyletic, because it does not include crocodylomorph...

n in 1942. Rhadinosuchidae was named in 1955 as a family that included Rhadinosuchus and the rauisuchian Procerosuchus

Procerosuchus

Procerosuchus is an extinct genus of rauisuchid rauisuchian. Fossils have been collected from the Late Triassic Santa Maria Formation in Geopark of Paleorrota, Rio Grande do Sul, Brazil, which is Carnian in age...

. When Rhadinosuchus was identified as a basal

Basal (phylogenetics)

In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 archosauriform in 2000, it was grouped with proterochampsids

Proterochampsidae

Proterochampsidae is a family of archosauriforms. Proterochampsids may have filled an ecological niche similar to modern crocodiles, and had a general crocodile-like appearance. They lived in what is now South America in the Middle and Late Triassic....

. Gualosuchus and Chanaresuchus were included in the family, although they are often described as belonging to the family Proterochampsidae. Proterochampsia is occasionally used as a larger taxon that encompasses both Proterochampsidae sensu stricto and Rhadinosuchidae.