''Charassognathus'' (meaning 'notched jaw') is an extinct
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
Late Permian
Late may refer to:
* LATE, an acronym which could stand for:
** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia
** Local-authority trading enterprise, a New Zealand business law
** Local average treatment effect, ...
cynodont
The cynodonts () (clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide varie ...
s. Described in 2007 from a locality near
Fraserburg
Fraserburg is a town in the Karoo region of South Africa's Northern Cape province. It is located in the Karoo Hoogland Local Municipality. The town has some of the coldest winters in South Africa.
The nearest towns are Williston, Sutherland, Lo ...
,
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 ...
, ''Charassognathus'' is one of the earliest and most
basal cynodonts. It is known only from the
holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...
, which dates from the
Late Permian
Late may refer to:
* LATE, an acronym which could stand for:
** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia
** Local-authority trading enterprise, a New Zealand business law
** Local average treatment effect, ...
Period
Period may refer to:
Common uses
* Era, a length or span of time
* Full stop (or period), a punctuation mark
Arts, entertainment, and media
* Period (music), a concept in musical composition
* Periodic sentence (or rhetorical period), a concept ...
. The
type and only species is ''C. gracilis''. The holotype (
SAM-PK-K 10369), found in the
''Tropidostoma'' Assemblage Zone of the
Teekloof Formation, is made up of a crushed
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 ...
, partial lower
jaw and one leg.
''Charassognathus'' was a
quadrupedal
Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor ...
predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill t ...
. It was named for a notch on its
coronoid process which most likely was the insertion point for a chewing muscle, the
adductor mandibulae externus Adductor may refer to:
* One of the anatomical terms of motion
* Adductor muscle (disambiguation)
* Adductor canal
The adductor canal, also known as the subsartorial canal or Hunter’s canal, is an aponeurotic tunnel in the middle third of the th ...
. ''Charassognathus'' was a small animal, with a skull only in length. Since the body of ''Charassognathus'' has not been discovered, its full length remains unknown, but estimates have been made at .
Description
''Charassognathus'' has a snout that makes up slightly less than half of the total length of its skull and a long facial process on its septomaxilla. Other than these two features its skull is that of a typical cynodont. The odd shape of its septomaxilla is more typical of
therocephalian
Therocephalia is an extinct suborder of eutheriodont therapsids (mammals and their close relatives) from the Permian and Triassic. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their t ...
s than other
cynodonts indicating that it may be close to a common ancestor between the two groups.
See also
*
List of therapsids
This list of therapsids is an attempt to create a comprehensive listing of all genera that have ever been included in the Therapsida excluding mammals and purely vernacular terms. The list includes all commonly accepted genera, but also genera tha ...
References
*
Prehistoric cynodont genera
Lopingian life
Lopingian synapsids of Africa
Permian South Africa
Fossils of South Africa
Fossil taxa described in 2007
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