MAJOR SUBGROUPS
 

Dinocephalians are a diverse group of basal therapsids which can be divided into 5 main groups. Click on a group below to find out more…

*Some regard Brithopodidae and Anteosauridae to be part of the same family.

* Some people divide the dinocephalians into two main groups – the carnivorous anteosaurs and the herbivorous tapinocephalians.

 

Brithopodidae

Brithopodidae are the most primitive, pelycosaur-like of all the dinocephalians. They are very long, carnivorous animals with a skull length up to 600mm. As with most dinocephalians, the lower incisors interlocked between the upper incisors and the canine teeth were large, but their jaw was relatively longer. The thickening of skull bones is beginning to appear in some species, notably Doliosaurus.

The name Brithopodidae is being used less often and being replaced by Anteosauridae (see below) which is a generic name for the carnivorous dinocephalians (Hopson & Barghusen, 1986).

Localities: Russia and some from the San Angelo Formation of Texas

Time period: Late Permian

 

Skull of a brithopodid, showing the large canine teeth, adapted for a carnivorous diet (Efremov, 1940).

 

Two Titanophoneus potens looking for their next meal. Note their large size, long heavy snouts with well developed canines and incisors. Used with permission from Kelly Taylor.

 

Anteosauridae

Anteosaurids are closely related to the brithopodids and they can be classified together as the Brithopia or Anteosauridae. They are present in the famous South Africa Karoo fauna (incidently where brithopodidae are absent) and represent a more advanced or specialised group of carnivorous dinocephalians. Anteosaurids are huge forms, with skulls between 500-800mm in length and have a deepened postorbital region of the skull. The bones of the skull are also thickened (pachyostosis).

Localities: South Africa, Karoo fauna

Time Period: Late Permian

Skull of Anteosaurus (Boonstra, 1954)

Titanosuchidae

The Titanosuchidae were primarily herbivorous, but also retained charcacteristics comparable to the Brithopidae, thus suggesting they had a partially carnivorous diet. They still had distinct canines, but they were much less prominent than in the anteosaurs and brithopopids and their incisors were also relatively small. The postcranial skeleton of titanosuchids is much better known than the anteosaurs and differs in profound ways. Firstly the bones are much larger, the vertebrate short and wide and the shoulder girdle is robustly built. Two well-established genera are recognized, the long-limbed form Titanosuchus and the short-limbed form Jonkeria.

Localities: South Africa (Karoo deposits)

Time Period: Permian

Titanosuchus was a 2.5m long member of the Titanosuchidae. It had sharp incisors (teeth at the front of the mouth) and fang-like canines.

The long limbed Titanosuchus (adapted from Macmillan, 1988).

 

The Jonkeria was gigantic even in dinocephalian proportions and measured approximately 4.5m in length. The body was robust, limbs were short and it had long piercing canines.

Skeleton of the short limbed Jonkeria (Van Hoepen, 1916).

 

Tapinocephalidae

The Tapinocephalidae were a family of giant herbivorous dinocephalians, closely related to the titanosuchids. However, the tapinocephalids are more specialized to herbivory than the titanosuchids with a less distinct canine and teeth specialised towards a herbivorous diet. The skulls are massive and either long-snouted (such as Struthiocephalus) or high and short (such as Moschops). In some species the skull only shows moderate thickness, while in others it has become greatly thickened into a huge mass of bone (pachyostosis). Taxonomic division of the family is primarily based upon the different degrees of skull thickness and snout shape.

Localities: South Africa

Time Period: Upper Permian

At 5m long, Moschops (see below and main banner from Gregory, 1926) was the biggest of all the dinocephalains. It was a herbivorous dinocephalian with a massive skull, barrel shaped body, large rib cage, tiny hands and feet, and a short tail. They had forelegs that sprawled out to the side, while the longer hindlegs were placed directly under the hips. It also had a large gut in order to process the vegetation it ate. It is found in the Karoo Beds of South Africa.

Moschops (adapted from Macmillan, 1988).

The Styracocephalidae are a family of small herbivores which are often grouped with the tapincephalidae. It is a fairly small form and has small horn-like structures on the top of its skull, presumably for intra-specific display, superficially similar to the structures of the Estennenosuchidae, but formed from different bones.

Localities: Russia & South Africa

Time Period: Permian

Estemmenosuchidae

The Estemmenosuchidae are an early family of large, herbivorous dinocephalians. They are distinguished by horn-like structures projecting from the top of their head. The exact function of these horns is not known, but they may have been used in courtship displays. Their skulls resemble that of Styracocephalus, but the horns are formed from different bones. They are a particularly problematic group because despite their early date of appearance they display herbivorous adaptations. This interferes with the generally accepted view that ancestral dinocephalians were carnivorous and then evolved into specialised herbivorous forms. Because of this there have been two main interpretations of evolutionary relationships within the dinocephalians. Hopson and Barghusen (1986) suggest the Estemmenosuchids are very early members of the Tapinocephalia, whereas some argue that the Estemmenosuchids are the most basal dinocephalian, leading to both the Anteosauria and Tapincephalia.

Localities: Russia

Time Period: Permian

 

Estemmenosuchus, showing the characteristic horn-like projections. Picture used with the permission of Karen Carr, a natural history artist.