''Procolophon'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of lizard-like procolophonid parareptiles that first appeared in 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 ...

(

Induan The Induan is the first age of the Early Triassic epoch in the geologic timescale, or the lowest stage of the Lower Triassic series in chronostratigraphy. It spans the time between 251.902 Ma and Ma (million years ago). The Induan is someti ...

) of

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 coun ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

, and

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...

. It persisted through the

Permian–Triassic extinction event The Permian–Triassic (P–T, P–Tr) extinction event, also known as the Latest Permian extinction event, the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, ...

, but went extinct in the beginning of the Early Middle Triassic. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specim ...

is ''P. trigoniceps''.

History of discovery

The first ''Procolophon'' fossil was discovered in the 1870s in Donnybrook, an area southwest of

Pietermaritzburg Pietermaritzburg (; Zulu: umGungundlovu) is the capital and second-largest city in the province of KwaZulu-Natal, South Africa. It was founded in 1838 and is currently governed by the Msunduzi Local Municipality. Its Zulu name umGungundlovu ...

in present-day

Kwa-Zulu Natal KwaZulu-Natal (, also referred to as KZN and known as "the garden province") is a province of South Africa that was created in 1994 when the Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu) and Natal Province were merged. It is locate ...

. The

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

was accessioned to Harry Seeley, who described the

in 1878. Numerous other fossils have been recovered since from localities across the

Eastern Cape The Eastern Cape is one of the provinces of South Africa. Its capital is Bhisho, but its two largest cities are East London and Gqeberha. The second largest province in the country (at 168,966 km2) after Northern Cape, it was formed in ...

and Free State provinces of

Description

''Procolophon'' reached a length up to , and is considered to have been a small

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...

insectivore A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores were ...

. The skull of ''Procolophon'' is distinct because of its latero-posteriorly facing paired cheek spikes, along with spiked dermal

ossicles The ossicles (also called auditory ossicles) are three bones in either middle ear that are among the smallest bones in the human body. They serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea). The absence of the auditor ...

. Paleontologists debate the function of the cheek spikes. Some paleontologists posit that the bony protrusions were points for muscle attachments. ''Procolophon'' also had large eyes, and may have had acute night vision. Its teeth were peg-like and suitable for crushing plant matter. The front of the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

was short and blunt with the nasal opening very close to the mouth.

Classification

''Procolophon'' is a basal member of

Procolophonidae Procolophonidae is an extinct family of small, lizard-like parareptiles known from the Late Permian to Late Triassic that were distributed across Pangaea, having been reported from Europe, North America, China, South Africa, South America, Anta ...

, a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...

of parareptiles that are closely related to larger, more

derived Derive may refer to: *Derive (computer algebra system), a commercial system made by Texas Instruments * ''Dérive'' (magazine), an Austrian science magazine on urbanism *Dérive, a psychogeographical concept See also * *Derivation (disambiguation ...

parareptiles such as the

pareiasaur Pareiasaurs (meaning "cheek lizards") are an extinct clade of large, herbivorous parareptiles. Members of the group were armoured with scutes which covered large areas of the body. They first appeared in southern Pangea during the Middle Permi ...

, '' Bradysaurus''.

Procolophonids Procolophonidae is an extinct family of small, lizard-like parareptiles known from the Late Permian to Late Triassic that were distributed across Pangaea, having been reported from Europe, North America, China, South Africa, South America, Antarc ...

are also related to mesosaurids and millerettids. ''Procolophon'' is also considered to share a sister-taxon relationship with ''

Tichvinskia ''Tichvinskia'' is an extinct genus of procolophonid parareptile 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 ag ...

'', a procolophonid from the lower

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

Correlation

''Procolophon'' occupied a wide geographic range. Fossils of the genus were found in the ''Lystrosaurus'' Assemblage Zone of the Katberg and Normandien Formations of South Africa, to the

Sanga do Cabral Formation The Sanga do Cabral Formation is an Early Triassic sedimentary rock formation found in Rio Grande do Sul, Brazil.Paraná Basin in eastern

, to the Fremouw Formation of the Transantarctic Mountains. Numerous

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

and

sister taxa In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

are also found in the lower

(

) of

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

, and

References

{{Portal bar, Paleontology Procolophonines Permian reptiles Triassic parareptiles Lopingian first appearances Late Triassic extinctions Late Triassic reptiles of Africa Triassic South Africa Fossils of South Africa Beaufort Group Prehistoric reptiles of Antarctica Triassic Antarctica Fossils of Antarctica Triassic reptiles of South America Triassic Brazil Fossils of Brazil Paraná Basin Fossil taxa described in 1876 Taxa named by Richard Owen Prehistoric reptile genera