''Patranomodon'' (from Greek ''patr-'' “father”, thus “father of anomodonts”) is an extinct genus belonging to the group of

Anomodontia Anomodontia is an extinct group of non-mammalian therapsids from the Permian and Triassic periods. By far the most speciose group are the dicynodonts, a clade of beaked, tusked herbivores.Chinsamy-Turan, A. (2011) ''Forerunners of Mammals: Ra ...

. Rubidge and Hopson named this anomodont in 1990 after discovering its skull.Rubidge, B. S., & Hopson, J. A. (1990). A new anomodont therapsid from South Africa and its bearing on the ancestry of Dicynodontia. ''South African Journal of Science'', ''86''(1), 43-45. ''Patranomodon'' is known to have ranged in the Karoo of Southern Africa.

Discovery and history

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 ...

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 ...

of ''Patranomodon'' was found in the ''Eodicynodon'' Assemblage Zone 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 ...

, belonging to the lowest biozone of the

Beaufort Group The Beaufort Group is the third of the main subdivisions of the Karoo Supergroup in South Africa. It is composed of a lower Adelaide Subgroup and an upper Tarkastad Subgroup. It follows conformably after the Ecca Group and unconformably underli ...

. The Beaufort Group time period extends from the middle of the Permian to the early Triassic period. It is one of the three main subdivisions of the

Karoo Supergroup The Karoo Supergroup is the most widespread stratigraphic unit in Africa south of the Kalahari Desert. The supergroup consists of a sequence of units, mostly of nonmarine origin, deposited between the Late Carboniferous and Early Jurassic, a peri ...

in what today is southern Africa. Rubidge and Hopson were the first to discover the skull of ''Patranomodon''. These paleobiologists also named ''Patranomodon'' and were the first to publish literature on it starting in 1990. The most abundant remains of ''Patranomodon'' were found on the Eastern Cape of South Africa; however, fossil parts were also found in Europe, China, as well as India, which indicated migration occurring among these terrestrial creatures. The

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

John Nyaphuli collected the fossil of this creature in South Africa and gave it the species name of "''Patranomodon nyaphuli''".

Palaeobiology

''Patranomodon'' have a short exposure of their palatine and

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has ...

, which creates a shorter face compared to other anomodontons.RUBIDGE, B. S. And HOPSON, J. A. (1996), A primitive anomodont therapsid from the base of the Beaufort Group (Upper Permian) of South Africa. Zoological Journal of the Linnean Society, 117: 115–139. Doi:10.1111/j.1096-3642.1996.tb02152.x This gives ''Patranomodon'' a shorter facial structure, shorter in length as well as small in size. They also have a reduced tabular, a slit-like interpterygoid vacuity, three sacral

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

e, and a screw-shape jaw. The genus has many features indicating its herbivorous behavior: the division of the external adductor muscles in the jaw into two separate components, the medial and lateral side, as well as using a propalinal jaw movement while feeding on plant material.King, G. M. (1994). The early anomodont Venjukovia and the evolution of the anomodont skull. ''Journal of Zoology'', ''232''(4), 651-673. The teeth formation of ''Patranomodon'' allows crushing and grinding to occur as the jaws connect and move. Other aspects include widening of the palatal areas for breaking down plant matter in feeding, widening of the external adductors, the higher raised jaw hinge, reduction in the number and size of teeth, and acquiring a horn that extends to the jaw. The transition from its carnivorous

ancestor An ancestor, also known as a forefather, fore-elder or a forebear, is a parent or ( recursively) the parent of an antecedent (i.e., a grandparent, great-grandparent, great-great-grandparent and so forth). ''Ancestor'' is "any person from w ...

to the herbivorous ''Patranomodon'' occurred rapidly compared to the longevity of the species of anomodonts.

Palaeoecology

The environment during the

Lopingian The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic. The Lopingian is often synonymous with the informal terms l ...

epoch of the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

, when ''Patranomodon'' roamed the Earth, was typically aquatic-based, with plentiful precipitation concentrated in the mountains and plateaux of terrestrial habitats. Rainfall was very frequent during this time. There were times of warm humid greenhouse-like climate with soil erosion and stagnation in the wetlands, which may have led to the mass

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the Endling, last individual of the species, although the Functional ext ...

s in middle to late Permian times. These environmental conditions created harsh living conditions for terrestrial creatures, some of which died off. The mass extinction affected most of the terrestrial and aquatic species; however, the terrestrial species evolved greatly after the mass extinction. ''Patranomodon'' was one of the early terrestrial species that evolved from the fully aquatic environments. Flash floods were the main reason why there were sediment deposits, along with overflowing rivers from melting ice caps.Rubidge, B. S., Hancox, P. J., & Catuneanu, O. (2000). Sequence analysis of the Ecca—Beaufort contact in the southern Karoo of South Africa. ''South African Journal of Geology'', ''103''(1), 81-96. Fossilization requires specific factors that allow preservation of hard tissues such as bone. In southern Africa, where ''Patranomodon'' lived during the Late Permian epoch, there was probably

migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

due to the progressive climatic drying and the shrinking of the basin. This migration occurred in a northward direction to warmer environments.Smith, R. M. H. (1990). A review of stratigraphy and sedimentary environments of the Karoo Basin of South Africa. ''Journal of African Earth Sciences (and the Middle East)'', ''10''(1-2), 117-137. Evidence for migration is also found in the distribution of fossils of certain

anomodont Anomodontia is an extinct group of non-mammalian therapsids from the Permian and Triassic periods. By far the most speciose group are the dicynodonts, a clade of beaked, tusked herbivores.Chinsamy-Turan, A. (2011) ''Forerunners of Mammals: Ra ...

s northward from the southern cape of Africa. The

, where ''Patranomodon'' was found in the fossil record, dominated most of the basin with fluvial sedimentation. During the Permian period, Europe, Africa, Asia, America, and Antarctica were joined in one large supercontinent called Pangea. Scattered fossils of Anomodonts provide evidence for this huge land mass as well as for migration from one end of the land mass to the other. Fluvial sedimentation refers to the sediment carried by streams and rivers that deposit into landforms, thus preserving the fossil skull of ''Patranomodon''. These streams and rivers were most likely formed by ice masses such as glaciers.

References

External links

{{Taxonbar, from=Q2982371 Anomodont genera Prehistoric synapsids of Africa Fossil taxa described in 1990 Dicynodonts

Discovery and history

Palaeobiology

Palaeoecology

See also

References

External links