Charassognathus
Encyclopedia
Charassognathus is an extinct genus
of Late Permian cynodont
. Described in 2007 from a locality near Fraserburg
, South Africa
, Charassognathus is the earliest and most basal
cynodont. It is known only from the Holotype
which dates from the upper Permian
Period. The type species
C. gracilis is the only species of Charassognathus. The holotype (South African Museum SAM-PK-K 10369) is made up of a crushed skull
, partial lower jaw
and one leg.
Charassognathus was a quadrupedal predator. 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. Charassognathus was a tiny animal, with a skull only 5 centimeters in length. Since the body of Charassognathus hasn't been discovered, its full length remains unknown, but estimates have been made at 50 centimeters.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of Late Permian cynodont
Cynodont
Cynodontia or cynodonts are a taxon of therapsids which first appeared in the Late Permian and were eventually distributed throughout all seven continents by the Early Triassic . This clade includes modern mammals and their extinct close relatives. They were one of the most diverse groups of...
. Described in 2007 from a locality near Fraserburg
Fraserburg
Fraserburg is a town in the Karoo region of South Africa's Northern Cape province.It was established in 1851 on the farm Rietfontein, and named after the Scottish immigrant Reverend Colin Fraser, and a church elder G.J. Meyburgh. Prior to the town establishment the earliest known inhabitants of the...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, Charassognathus is the earliest and most basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
cynodont. It is known only from the Holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
which dates from the upper Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
Period. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
C. gracilis is the only species of Charassognathus. The holotype (South African Museum SAM-PK-K 10369) is made up of a crushed skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
, partial lower jaw
Jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...
and one leg.
Charassognathus was a quadrupedal predator. It was named for a notch on its coronoid process
Coronoid process of the mandible
The mandible's coronoid process is a thin, triangular eminence, which is flattened from side to side and varies in shape and size....
which most likely was the insertion point for a chewing muscle, the adductor mandibulae externus. Charassognathus was a tiny animal, with a skull only 5 centimeters in length. Since the body of Charassognathus hasn't been discovered, its full length remains unknown, but estimates have been made at 50 centimeters.