''Pristerodon'' is an extinct
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
dicynodont
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 ...
therapsid from the Late Permian of South Africa, Zambia and India.
Paleobiology
Brain and senses
''Pristerodon'' were among the earliest land animals able to hear airborne sound as opposed to hearing via ground vibrations. A South African specimen studied with neutron tomography
has shown evidence of an
eardrum
In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit changes in pres ...
on its lower jaw with the implication that it was hearing impaired during the act of chewing. The specimen had a 3mm cavity for
cochlea
The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus (cochlea), modiolus. A core component of the cochlea is the organ of Cort ...
which transformed sound frequency ranges into nerve impulses sent on to the brain.
Ecology
''Pristerodon'' has been found in the
Kundaram Formation of India,
Usili Formation of
Tanzania
Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...
, the
Upper Madumabisa Mudstone Formation of Zambia, and the
Teekloof Formation and
Abrahamskraal Formation of South Africa.
Phylogeny
''Pristerodon'' in a
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 ...
modified from Angielczyk and Rubidge (2010) showing the
phylogenetic
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 dat ...
relationships of
Dicynodont
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 ...
ia:
See also
*
List of therapsids
This list of therapsids is an attempt to create a comprehensive listing of all Genus, genera that have ever been included in the Therapsida excluding mammals and purely vernacular terms. The list includes all commonly accepted genera, but also gene ...
References
External links
The main groups of non-mammalian synapsids at Mikko's Phylogeny Archive
Dicynodontia
Lopingian synapsids of Africa
Fossils of South Africa
Fossils of Zambia
Lopingian synapsids of Asia
Fossils of India
Fossil taxa described in 1868
Taxa named by Thomas Henry Huxley
Anomodont genera
Permian India
{{anomodont-stub