''Procolophon'' (from , 'before' and , 'summit') is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of lizard-like

procolophonid 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 ...

parareptiles Parareptilia ("near-reptiles") is an extinct group of basal sauropsids ("reptiles"), traditionally considered the sister taxon to Eureptilia (the group that likely contains all living reptiles and birds). Parareptiles first arose near the end ...

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 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...

(

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 251.9 Ma and 249.9 Ma (million years ago). The Induan is so ...

) of

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

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 ...

, 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 (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

. It persisted through the

Permian–Triassic extinction event The Permian–Triassic extinction event (also known as the P–T extinction event, the Late Permian extinction event, the Latest Permian extinction event, the End-Permian extinction event, and colloquially as the Great Dying,) was an extinction ...

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

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

is ''P. trigoniceps''.

History of discovery

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

Pietermaritzburg Pietermaritzburg (; ) is the capital and second-largest city in the province of KwaZulu-Natal, South Africa after Durban. It was named in 1838 and is currently governed by the Msunduzi Local Municipality. The town was named in Zulu after King ...

in present-day

Kwa-Zulu Natal KwaZulu-Natal (, also referred to as KZN) is a Provinces of South Africa, province of South Africa that was created in 1994 when the government merged the Zulu people, Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu language, Zulu) and ...

. 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 preserve ...

was accessioned to

Harry Seeley Harry Govier Seeley (18 February 1839 – 8 January 1909) was a British paleontologist. Early life Seeley was born in London on 18 February 1839, the second son of Richard Hovill Seeley, a goldsmith, and his second wife Mary Govier. When his fa ...

, 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 nine provinces of South Africa. Its capital is Bhisho, and its largest city is Gqeberha (Port Elizabeth). Due to its climate and nineteenth-century towns, it is a common location for tourists. It is also kno ...

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 evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

insectivore file:Common brown robberfly with prey.jpg, A Asilidae, robber fly eating a hoverfly An insectivore is a carnivore, carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the Entomophagy ...

. 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 irregular bones in the middle ear of humans and other mammals, and are among the smallest bones in the human body. Although the term "ossicle" literally means "tiny bone" (from Latin ''ossi ...

. 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, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

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 (biology), 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, Sou ...

, a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

that are closely related to larger, more derived parareptiles such as the

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

, ''

Bradysaurus ''Bradysaurus'' is a genus of large, primitive and widespread pareiasaur. They possessed a covering of armoured scutes, likely serving as defense against their main predators, the gorgonopsians. Fossils of ''Bradysaurus'' are known from the ''T ...

''. Procolophonids are also related to mesosaurids and millerettids. ''Procolophon'' was considered to share a sister-taxon relationship with '' Tichvinskia'', a

from the lower

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

. 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 follows a

phylogenetic analysis In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...

by Modesto and Damiani (2007) in which ''Procolophon'' is defined in

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tree ...

with '' Thelerpeton'' and

Leptopleuroninae Leptopleuroninae is an extinct subfamily of procolophonid reptiles. It is defined as all taxa closer to '' Leptopleuron lacertinum'' than to ''Procolophon trigoniceps''. The oldest member of Leptopleuroninae is '' Phonodus dutoitorum'' from the ...

: In their

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 ...

, Butler ''et al''. (2023) defined ''Procolophon'' as a sister taxon to '' Teratophon'' and ''Thelerpeton'' or only to ''Teratophon'' within

Procolophoninae Procolophoninae is an extinct subfamily of procolophonid parareptiles from the late Early Triassic to the early Middle Triassic (Olenekian and Anisian stages) of Africa, Antarctica, Asia, Europe and South America. Currently, the oldest-known pr ...

. The results are shown in two cladograms below: Analyses 1 and 3: Strict consensus of 760 and 18 most parsimonious trees (MPTs). Analysis 2: Single MPT.

Correlation

''Procolophon'' occupied a wide geographic range. Fossils of the genus were found in the ''Lystrosaurus'' Assemblage Zone of the

Katberg Katberg is a hamlet high up in Raymond Mhlaba Municipality, Amathole District Municipality, in the Eastern Cape province of South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost co ...

and

Normandien Formation The Normandien Formation is a Triassic-age rock formation located in Free State, South Africa. It is where the fossils of Ericiolacerta, a subtaxa of Ericiolacertidae, were found. Fossil content Among others, these fossils were reported fro ...

s 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 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 eastern

, to the

Fremouw Formation The Fremouw Formation is a Triassic-age rock formation in the Transantarctic Mountains of the Ross Depenency of Antarctica. It contains the oldest known fossils of tetrapods from Antarctica, including synapsids, reptiles and amphibians. Fossiliz ...

of the

Transantarctic Mountains The Transantarctic Mountains (abbreviated TAM) comprise a mountain range of uplifted rock (primarily sedimentary) in Antarctica which extends, with some interruptions, across the continent from Cape Adare in northern Victoria Land to Coats L ...

. Numerous

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

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 lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, and

References

External links

* {{Portal bar, Paleontology Procolophoninae 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