''Paraburnetia'' is an extinct genus of
biarmosuchian
Biarmosuchia is an extinct clade of non-mammalian synapsids from the Permian. Biarmosuchians are the most basal group of the therapsids. They were moderately-sized, lightly built carnivores, intermediate in form between basal sphenacodont "pelyc ...
therapsids from the
Late Permian
Late or LATE may refer to:
Everyday usage
* Tardy, or late, not being on time
* Late (or the late) may refer to a person who is dead
Music
* ''Late'' (The 77s album), 2000
* Late (Alvin Batiste album), 1993
* Late!, a pseudonym used by Dave Groh ...
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 ...
. It is known for its species ''P. sneeubergensis'' and belongs to the family
Burnetiidae
Burnetiidae is an extinct family of biarmosuchian therapsids that lived in the Permian period whose fossils are found in South Africa, Zambia and Russia. It contains ''Bondoceras'', ''Bullacephalus'', ''Burnetia'', ''Mobaceras'', ''Niuksenitia'' ...
.
''Paraburnetia'' lived just before the
Permian–Triassic mass extinction event.
The etymology of ''Paraburnetia sneeubergensis'' comes from ''para'', meaning beside or near; ''
Burnetia
''Burnetia'' is an extinct genus of biarmosuchian therapsids in the family Burnetiidae, from the Late Permian of South Africa. ''Burnetia'' is known so far from a single holotype skull lacking the lower jaws described by South African paleontolo ...
'' indicating the first named member of the clade; and ''sneeubergensis'' for the location the
Sneeuberge
The Sneeuberge or Sneeuberg mountain range was historically known as “Sneeuwbergen”, meaning ‘snow mountains’ in Cape Dutch, and refers to a significant portion of Southern Africa's Great Escarpment in the Cradock, Murraysburg, Rich ...
mountains above where the specimen was found.
''P. sneeubergensis'' is known by its knobby skull,
which is a shared
synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel Phenotypic trait, character or character state that has evolution, evolved from its ancestral form (or Plesiomorphy and symplesiomorphy, plesiomorphy). A synapomorphy is an apomorphy sh ...
with ''B. mirabilis''
and ''P. viatkensis'' They are
synapsids
Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant rept ...
, from which, their clade of therapsids is derived from.
[Rubidge, B., & Sidor, C. (2001). Evolutionary patterns among Permo-Triassic therapsids. Annual Review of Ecology and Systematics, 32, 449.] Descending from one of the first therapsids,
biarmosuchus
''Biarmosuchus'' is an extinct genus of biarmosuchian therapsids that lived around 267 mya during the Middle Permian period. ''Biarmosuchus'' was discovered in the Perm region of Russia. The first specimen was found in channel sandstone that ...
, ''Paraburnetia'' evolved prominent canine teeth, a long zygomatic process that extends under the orbit, and shorter phalanges with fewer joints that the lizard-like
pelycosaurs
Pelycosaur ( ) is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term mammal-like reptile was used, and Pelycosauria was considered an order, but this is now thoug ...
.
They were small to medium in sized carnivores.
Burnetiamorphs distinguished themselves from the basal forms of Biarmosuchians by developing bumpy knobs on their skulls, specifically towards the posterior of the skull and on the nasal.
History and discovery
''Paraburnetia'' was first discovered by a team from the South African Museum working in the southern
Karoo Basin
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 per ...
during July 2000. The specimen had been separated into two large portions. The first of which was originally identified due to the 'knob' on the synapsid skull. The snout was found downstream in the lower Beau-fort Group. The fitting of these two portions created the most complete skull of a
burnetiid
Burnetiidae is an extinct family of biarmosuchian therapsids that lived in the Permian period whose fossils are found in South Africa, Zambia and Russia. It contains '' Bondoceras'', ''Bullacephalus'', ''Burnetia'', '' Mobaceras'', '' Niuksenit ...
therapsid to date.
Previous
burnetiid
Burnetiidae is an extinct family of biarmosuchian therapsids that lived in the Permian period whose fossils are found in South Africa, Zambia and Russia. It contains '' Bondoceras'', ''Bullacephalus'', ''Burnetia'', '' Mobaceras'', '' Niuksenit ...
s found were ''Burnetia mirabilis''
[R. Broom 1923. On the structure of the skull in the carnivorous dinocephalian reptiles. Proceedings of the Zoological Society of London 2:661–684.] from South Africa and Proburnetia viatkensis from Russia. Historically, burnetiamorphs were difficult to place due to sharing characteristics with
dinocephalians
Dinocephalians (terrible heads) are a clade of large-bodied early therapsids that flourished in the Early Permian, Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinct ...
and
gorgonopsians
Gorgonopsia (from the Greek Gorgon, a mythological beast, and 'aspect') is an extinct clade of sabre-toothed therapsids from the Middle to the Upper Permian, roughly between 270 and 252 million years ago. They are characterised by a long and ...
.
More recently, a series of taxa have been added to the group and its systematics have become better codified. Burnetiamorpha currently encompasses six genera: ''Bullacephalus, Burnetia, Lemurosaurus, Lobalopex, Niuksenitia,'' and ''Proburnetia''
Description
''Paraburnetia'' is diagnosed by the characteristics of a superior temporal bulbous vertical horn, an upper orbital boss with a defined apical crest, and an elongated palatine-pterygoid boss.
Paraburnetia and Proburnetia share features indicating a sister-taxon relationship, including the presence of a well-developed median nasal crest and tall superior orbital bosses
Distinctive characteristics that characterize it as a Burnetiamorph are its: "triangular supraorbital bosses; ridgelike nasal and frontal crests; bosses on the suborbital bar; swollen knob on the squamosal lateral to the quadrate; small incisors; and thickened rim along the posterior margin of the squamosal".
Skull
In dorsal view, size of the skull is more similar to those of ''Bullacephalus'', ''Burnetia'', and ''Proburnetia'', than the slightly smaller skull size of ''Lemurosaurus'' or ''Lobalopex''.
The skull roof is triangular in dorsal
view, with the width of the skull roof being narrower than its length.
The specimen's skull measures a length of 175 mm.
Additionally, the skull appears higher than the skull of ''Burnetia'' or ''Lobalopexdue'' due to the level of its preservation lacking dorsalventral compression.
As shared by many basal therapsids (e.g.,
dinocephalians
Dinocephalians (terrible heads) are a clade of large-bodied early therapsids that flourished in the Early Permian, Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinct ...
,
anomodonts
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. Anomodonts were very diverse during the Middle Permi ...
), the maxilla in Paraburnetia contacts the prefrontal.
In ''Paraburnetia'', the maxilla stretches posteriorly and extends to meet the squamosal.
This is different from the situation reported by for Proburnetia, sister taxa to Paraburnetia,
[Rubidge, B. S., & Sidor, C. A. (2002). On the cranial morphology of the basal therapsids Burnetia and Proburnetia (Therapsida: Burnetiidae). Journal of Vertebrate Paleontology, 22(2), 257-267.] where the maxilla was not considered to extend as far posteriorly.
There are four postcaniniforms in the left maxilla and
five postcaniniforms in the right maxilla.
This differs from the seven postcaniniforms that ''probernetia'' have.
The premaxilla, that make up the tip of the snout, is relatively short and has five small teeth.
Additionally, the nasal dorsal surface is a thickened, median boss.
This is similarly present in Proburnetia, but more pronounced.
All burnetiamorphs except Lemurosaurus possess a median nasal boss.
In dorsal view, the frontal crest is prominent in Paraburnetia more so than in Proburnetia.
It flattens and broadens until it reaches the
interorbital region
The interorbital region of the skull is located between the eyes, anterior to the braincase. The form of the interorbital region may exhibit significant variation between taxonomic groups.
In oryzomyine rodents, for example, the width, form, and ...
.
The squamosal appears thickened along the posterior border with the tabular.
[Day, M. O., Smith, R. M., Benoit, J., Fernandez, V., & Rubidge, B. S. (2018). A new species of burnetiid (Therapsida, Burnetiamorpha) from the early Wuchiapingian of South Africa and implications for the evolutionary ecology of the family Burnetiidae. Papers in Palaeontology, 4(3), 453-475.]
The supraorbital boss shape varies among burnetiamorphs.
Basal forms such as Lemurosaurus and Lobalopex have the primitive condition of having a single supraorbital boss.
Paraburnetia and Proburnetia have this variation.
Whereas Bullacephalus and Burnetia show the derived variation in which the supraorbital boss comprises two separate swellings and a valley between.
[Sidor, C. A., Hopson, J. A., & Keyser, A. W. (2004). A new burnetiamorph therapsid from the Teekloof Formation, Permian, of South Africa. Journal of Vertebrate Paleontology, 24(4), 938-950.] Paraburnetia lack the prominent anterior dorsal orbital depression in the fossa as seen in ''Bullacephalus'', ''Burnetia'', and ''Proburnetia''.
The prominent 'knobs' that are supratemporal are created primarily by squamosal and parietal.
Unique among burnetiamorphs, the supratemporal 'knob' extends dorsally.
The Parietal foramen is thickened to crease a large swelling bump.
Palate
The most notable and distinct characteristic of the palate is that the elongated palatine part of the palatinepterygoidis relative to ''Proburnetia''.
In ''Bullacephalus'', the pterygoid and palatine flare combined is very wide. This is in contrast to the narrow flare shown by ''Burnetia'' and ''Proburnetia''.
As shared by ''burnetia, labalopex, and proburnetia'', ''paraburnetia'' lack teeth on the pterygoid that has expanded laterally.
Lower Jaw
In lateral view, the lower jaw has a long, dentary that provides most of the lateral surface.
Near the coronoid, the dorsal rim swells and thickens, as in other biarmosuchians.
Four large incisiform teeth are present on either side of the lower jaw, while an additional small one is present adjacent to the midline.
This small incisiform is much shorter than the rest and appears to be a replacement tooth that is not yet fully erupted.
The coronoid element is a flat, triangular element, which differs from other biarmosuchians coronoid element shape.
''Paraburnetia'' have large reflected lamina
and the angular has the same ridge structure as ''Lemurosaurus'' and ''Lobalopex''.
Biostratigraphic History

Burnetiamorph biostratigraphic overlap in Beaufort Group of South Africa is extremely rare.
[Sidor, C. A. (2015). The first biarmosuchian from the upper Madumabisa Mudstone Formation (Luangwa Basin) of Zambia. Palaeontologia africana, 49, 1-7.] The single event of overlap was the discovery of ''Lemurosaurus'' and ''Paraburnetia''. The Beaufort Group is mudrock, with thick layers of multicolored
siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.
Although its permeabil ...
underneath.
[Smith, R. M. H. 1987. Morphology and depositional history of exhumed Permian point-bars in the southwestern Karoo, South Africa. Journal Sedimentary Petrology 57:19–29.] Floodplains are connected with rivers.
Although the Beaufort Group is now semi-desert, it has been hypothesized to have had forests historically and been cold since it was near the arctic in the time of Pangea.
The Beaufort group is known for
dicynodontia
Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivores that typically bore a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, t ...
fossils and there are many co-occurrences of burnetiamorphs found near other dicynodonts.
The co-occurrence of the two burnetiamorphs appeared in the
Cistecephalus Assemblage Zone
The ''Cistecephalus'' Assemblage Zone is a tetrapod assemblage zone or biozone found in the Adelaide Subgroup of the Beaufort Group, a majorly fossiliferous and geologically important geological group of the Karoo Supergroup in South Africa. T ...
.
In 1838, Andrew Geddes Bain was first to discover fossil reptiles in the Beaufort Zone.
[Rubidge, B. S. (1990). A new vertebrate biozone at the base of the Beaufort Group, Karoo Sequence (South Africa).] The Beaufort Group has become famous for Permian and Triassic fossils found and has since been subdivided into sub-zones based on
biostratigraphy
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology ...
.
The third zone, of six zones, suggested by Broom being
Cistecephalus Assemblage Zone
The ''Cistecephalus'' Assemblage Zone is a tetrapod assemblage zone or biozone found in the Adelaide Subgroup of the Beaufort Group, a majorly fossiliferous and geologically important geological group of the Karoo Supergroup in South Africa. T ...
.
Biarmosuchian fossils are rare, with only thirty specimens currently discovered.
Of 3,755 fossils found from the Cistecephalus AZ, only four are biarmosuchians.
Due to the lack of stratigraphic co-occurrence, burnetiamorphs most likely have a wide distribution on
Pangea
Pangaea or Pangea ( ) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia (continent), Siberia during the Carboniferous period ...
.
Evidence of this wide distribution is supported by the findings in collecting areas in Russia and South Africa.
Despite burnetiid species occurrences being rare and discovered from different zones, the family was species-rich, with one specimen per genus, suggesting that they had high rates of speciation and extinction.
Classification
''Paraburnetia'' belongs to the clade
burnetiidae
Burnetiidae is an extinct family of biarmosuchian therapsids that lived in the Permian period whose fossils are found in South Africa, Zambia and Russia. It contains ''Bondoceras'', ''Bullacephalus'', ''Burnetia'', ''Mobaceras'', ''Niuksenitia'' ...
, a subdivision of the greater clade biarmosuchian therapsids.
Biarmosuchians are typically considered the most basal major lineage of therapsids.
Biarmosuchia consists of a paraphyletic series of basal biarmosuchians that are fairly typical early therapsids, and the derived clade Burnetiamorpha, characterized by skulls ornamented by horns and bosses.
The close morphological similarity between Paraburnetia and Proburnetia indicates that there was faunal interaction between their zones in early
Wuchiapingian
In the geologic timescale, the Wuchiapingian or Wujiapingian (from in the Liangshan area of Hanzhong, Shaanxi Province ) is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or S ...
.
On the geological timescale, Wuchiapingian was a stage of the Permian. Additionally, an analysis of the phylogenetic relationships showed that Burnetia, Bullacephalus, Niuksenitia, Paraburnetia, and Proburnetia are within clade Burnetiidae.
Within Burnetiidae, Proburnetia and Paraburnetia are sister taxa and Lemurosaurus is the most basal burnetiamorph.
Paleobiology
Due to retrieving only the skull of the ''paraburnetia'' specimen and the other Burnetiidae, there is little information on their entire body morphology. However, knowledge of carnivorous traits and widespread dispersal of burnetiidae occurrences follows the pattern that carnivore species decrease in density near the edge of their ranges as a result of their environment resources not being able to support as many. Therefore, burnetiamorphs populations for a given area were inevitably lower than for herbivores living in the same region.
[P ET ERS, R. H. and WASS EN B ERG, K. 1983. The effect of body size on animal abundance. Oecologia, 60 (1), 89–96.] This indicates that burnetiamorph species in the
Karoo Basin
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 per ...
were a result of the land being on the edge of their territory range, in which case same species should be found in adjacent regions, but not the same regions.
Recent Discoveries and Implications
The new finding of sister taxa ''Lende chiweta'' indicates that Africa may have been a migration corridor between the southern and northern parts of Pangea during the late Permian.
[Citation for this article: Kruger, A., B. S. Rubidge, F. Abdala, E. Gomani Chindebvu, and L. L. Jacobs. 2015. Lende chiweta, a new therapsid from Malawi, and its influence on burnetiamorph phylogeny and biogeography. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1008698.]
See also
*
therapsid;
*
Proburnetia
''Proburnetia'' is an extinct genus of biarmosuchian therapsids in the family Burnetiidae, from the Late Permian of Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countrie ...
;
*
Biarmosuchus
''Biarmosuchus'' is an extinct genus of biarmosuchian therapsids that lived around 267 mya during the Middle Permian period. ''Biarmosuchus'' was discovered in the Perm region of Russia. The first specimen was found in channel sandstone that ...
;
*
burnetiidae
Burnetiidae is an extinct family of biarmosuchian therapsids that lived in the Permian period whose fossils are found in South Africa, Zambia and Russia. It contains ''Bondoceras'', ''Bullacephalus'', ''Burnetia'', ''Mobaceras'', ''Niuksenitia'' ...
;
References
{{Taxonbar, from=Q4291241
Burnetiamorpha
Prehistoric therapsid genera
Lopingian synapsids of Africa
Fossil taxa described in 2006
Lopingian genus first appearances
Lopingian genus extinctions