The family was erected bv Efremov in 1954 to include the carnivorous therapsids of the Russian Permian Copper Sandstones and other Cis-Uralian localities, including both those of the Cis-Uralian Deinocephalian Complexes and the Isheevian Deinocephalian Complex. In the same year Boonstra created the family Anteosauridae for the giant carnivorous dinocephalians of the South African Lower Beaufort (Tapinocephalus Zone). In his 1962 monograph on American and Russian mid Permian reptiles Olson places the distinct herbivorous brithopodid Deuterosaurus in a family of its own. For several decades these three families are considered distinct if closely related. In her 1988 monograph on the "Anomodonta" Gillian M. King suggested in subfamily distinction, although rejecting the status of the Deuterosauridae. The current cladistic-based tendency is of course to do away with these Linnean taxa altogether.
A group of primitive carnivorous dinocephalians. The skull is high and narrow. The palatal teeth - the teeth on the roof of the mouth, a feature of many Paleozoic tetrapods - are enlarged and usually confined to a kidney-shaped cluster on each palatine (near the outer tooth row), any on the pterygoid flange reduced. The marginal teeth (teeth in the "normal" position) are of three types: anterior (front or incisor), canine, and cheek teeth. here we have the further differentiation of teeth types along the line to mammalhood. The incisors (the teeth at the front) each have a small ledge or "heel", a distinctive dinocephalian feature that only the Estemmenosuchids lack. The canine is very large in all brithopodids, even the herbivorous ones. There are usually about ten cheek teeth (although the number can be very variable, dependent on age and tooth replacement), possessing bulbous crowns, and they may decrease in size from front to rear. There is a "step" or upturning in the premaxillary bone of the upper jaw, so the front of mouth curves strongly upwards (a somewhat more distinct "kink" (possibly a mobile joint) can be seen among some archosaurs such as proterosuchid thecodonts and coleophysid dinosaurs). The postorbital bone and bar behind the eye are large, modified to producean area for the attachment of the superficial adductor jaw muscles on the outer surface of skull. There is a tendency towards pachytosis, the thickening of the roof of the head that is a common dinocephalian characteristic and indicative of "head-butting" intra-specific behaviour (rivalry for mates and/or territory). This takes the form of a tuberosity around the pineal opening, in advanced forms as a bony "boss" (almost like a low mound). There is a large canal for parietal organ ("third eye", probably tied in with the animal's diurnal and seasonal cycle or biorhythm). The shoulder girdle is fairly light, with a narrow interdavicle, clavicle, and scapular blade. The femur (thigh bone) is slender and curved. These were, in spite of their size, probably quite agile animals, although possibly semi-aquatic.
The stance of a typical brithopodid like Titanophoneus was primitive, because rather than the limbs being drawn in under the body the stance was more sprawling. Olson notes that the Russian dinocephalian assemblages indicate environments tied to water, and Boonstra considered that the roughly contemporary Anteosaurus was a slinking crocodile-like semi-aquatic forms. The long tail, weak limbs, and sprawling posture do indeed suggest some sort of crocodile-like existence. However the thickened skull-roof indicates that these animals were quite able to get about on land, if they were to practice the typically dinocephalian head-butting behaviour. All other head-butters - pachycephalosauran dinosaurs, titanothere ungulates, and goats - were or are completely terrestrial. Perhaps these animals spent some time in the water but were active on land during the mating season, and probably quite able to get about on land to hant for prey (consider a modern sprawler/ambush preditor like the komodo dragon lizard).
There is no denying these were efficient preditors, more advanced than earlier and more primitive Biarmosuchid and Eotitanosuchid carnivorous therapsids, as the temporal opening behind the eye socket was larger, indicating a greater muscle mass available for closing the lower jaw. And with skull lengths of 50 to 100 cm, overall lengths of some 5 to 6 or 7 meters, and live weights of easily 500 kg, animals like Titanophoneus, Doliosauriscus, and Anteosaurus played the role of super-predator in the terrestrial tetrapod assemblages of the Capitanian epoch that the equally large Eotitanosuchus did during the preceding Wordian epoch, and the 4 to 5 meter Dimetrodon angelensis did during the Roadian epoch.
A full understanding of Brithopodid/Anteosaurid phylogeny has to await greater scrutiny of the available remains. Much of the Russian material is fragmentary, and a lot of this will no doubt turn out to be synonymous with the better known forms. It was originally thought that the earliest Brithopodid was the very fragmentary American Eosyodon Olson, of Roadian age. It now seems that all of the proto-therapsids Olson described in his monograph are chimeras - mostly misinterpretations of Caseid pelycosaurs [Kammerer]. That leaves the Russian Ocher fauna from Ezhovo (probably early Wordian age) as the oldest known brithopodids. Two species are known from this period. Significantly, Archaeosyodon is known only from the skull, and Chthamaloporus only from some postcrania. It is not unlikely that these two thus represent the same animal. The skull is typical of a fairly primitive Brithopodid and indicates a reasonably large animal - perhaps a large preditor intermediate in size between the dog-sized Biarmosuchus and the huge Eotitanosuchus, both of which were contemporary. The postcrania however includes a pelvic girdle quite unique from that of other brithopodids, indicating that this type represents a side-branch rather than a direct ancestor.
By the early Capitanian (late Kazanian - Bashkirian subzone), perhaps several million years later, the gigantic Eotitanosuchid superpreditors are gone, along with most of their Estemmenosuchid herbivore prey (perhaps the victims of a minor mass-extinction) and only a few smallish brithopodids remain. They seem to have diverged into at least two distinct lineages - the primitive carnivorous types (Syodon and Brithopus - subfamily Brithopidinae) and the more specialised herbivores (Deuterosaurus). The latter perhaps filled the ecological role vacated by the Estemmenosuchids.
By Kargalian times, at least a million or so years later, all the animals had grown in size, evolving into bigger and bigger types. A big species of Brithopus was joined by a giant Admetophoneus (subfamily Anteosaurinae), and the Deuterosaurs had also increased in size, and were now existing alongside the big advanced Tapinocephaline herbivores. These animals are by and large a lot bigger than those that existed during Bashkirian time.
By the time of the forms that have been found at Isheevo, the continuing basal primitive types like Syodon and Brithopus, and the advanced giant carnivorous forms like Titanophoneus and Doliosauriscus, are flourishing. The Deuterosaurs are gone, perhaps replaced by the Tapinocephalines. This seems to be the golden age of Brithopodid diversity, and indeed of the Dinocephalians in general. The South African Anteosaurus (Tapinocephalus zone), a representative of the Titanophonine-Doliosaur lineage (subfamily Anteosaurinae), seems to have existed at this time and also slightly later.
It is interesting that whereas in the South African temperate zone fauna there is only one Brithopodid preditor (the giant Anteosaurus), in the tropical Isheevo fauna (yes, at the time Russia was located over the equator!) there are four. Perhaps there were more ecological niches in the tropics for these animals. Perhaps some of the species will turn out to be synonyms or juveniles of other forms. Perhaps the smaller brithopodids like Syodon filled the same ecological niche as the similiarly sized Titanosuchus did in the temperate regions. Much still remains to be known about these amazing animals.
Guild/Ecological niche: large to very large semi-aquatic to terrestrial ambish preditors, some forms omnivores and herbivores
Modern equivalent: crocodilian???
Time: middle Permian ( Wordian to Capitanian)
Distribution: fossil remains are known from eastern Russia, South Africa, and China; it is almost certain that these animals had a worldwide ( Pangean) distribution
preferred food: other tetrapods, large freshwater fish?, some forms were omnivorous and a few herbivorous
length: upto 6 meters (skull: upto 80cm to 1 meter)
weight: upto 600 kg and more
Metabolism: partially endothermic gigantotherms (Homeotherms)
Predators: none (top of food chain)
Ancestor: Basal Therapsid (Tetraceratops or proto-Eotitanosuchus-like ancestor?)
Replaced by: Large Gorgonopsids
Descendents: Titanosuchidae; possibly also Styracocephalidae?
Taxonomic status - Family
Anteosauria |--Stenocybidae `-+-Brithopodidae / Anteosauridae `--Brithopodinae (paraphyletic) |--Archaeosyodon |--Syodon |--Brithopus `-+-Anteosaurinae | `-+-Titanophoneus | |-Admetophoneus | `--Anteosaurini | |--Doliosauriscus | `--Anteosaurus `--Deuterosaurinae (Deuterosaurus only)
Primitive, small to large, carnivorous and omnivorous brithopidids with the quadrate condyles (at the rear of the skull) narrowed anteroposteriorly (from front to rear). This is a paraphyletic and perhaps artificial grouping.
genus Archaeosyodon Chudinov 1960
A large carnivorous brithopodid. The skull is massive, comparatively high, and broad at the rear. The upper borders of the orbits (eye-sockets) and skull roof in the fronto-parietal region (from somewhat in front of the eyes to the raer of the top of the skull) are strongly thickened, indicating the typical "head-butting" behaviour. The temporal openings (for muscle attachment) are broadly open above. On each palatine bone are some fifteen teeth of varied sizes. The canines are short and curve backwards. The palate is primitive, especially in the arrangement of the palatal teeth and the position of the short deep forwardly placed choanae. The marked regularity of the marginal ("ordinary position") teeth and the very broadly open temporal opening also appear to be primitive features, as is probably also the positions of insertion of the adductor muscles.
genus Chthamaloporus Chudinov 1964
"This genus differs drastically from all other brithopod genera by the structure of the pelvis whose main characters are: proximity of the acetabula; great height of the ischiadic symphysis; presence of a powerful finger-shaped process on the anterior edge of ilium" (King, 1988). It is entirely possible that this specimen, known only from these post-cranial remains, might be the same as a species like Archaeosyodon which occurs in the same deposits and is known only from the skull.
Brithopus Kutorga 1838
This genus was based upon materials from the Copper Sandstones. This is a fairly large animal (length about 2.5 to 3 meters), rather similiar in general build and features to Titanophoneus, but possibly differing from it by a (probably) smaller number of anterIor teeth and greater number of postcanine teeth (9-10 instead of 8). However the tooth count in brithopodids, as in dinocephalians in general, is a very variable even in species. This is a typically early therapsid, as indicated by the skeleton. The shoulder girdle is typical of primitive therapsids, very similiar to the massive shoulder girdles of the Pelycosauria, indicated perhaps an inefficent sprawling posture (which requires a stronger muscle support). As in Dimetrodon the glenoid is somewhat screw-shaped, implying a limited range of movement
There are four named species, two of which,B. priscus Kutorga, from the lower part of the upper Copper Sandstone, and the larger and somewhat later B. ponderus, which may represent an ecological succession, the latter having evolved from and replaced the former. However, the known specimens are fragmentary and the taxonomy, morphology, and stratigraphy, all leave much to be desired.
This animal is known under a number of generic names (as various fragmentary remains were discovered in the early to mid nineteenth century but not connected), including Orthopus primaevus Kutorga 1838, Rhopalodon wangenheimi Fischer 1841, Dinosaurus murchisoni (Fischer 1845) ( = Rhopaladon murchisoni) and Eurosaurus verus Meyer 1866. Yes, Dinosaurus is not necessarily a dinosaur! (or at least the name has been formally applied to a non-dinosaur, but in any case is no longer valid.)Brithopus? fischeri (Eichwald) 1860
Brithopus priscus Kutorga 1838
A comparatively large carnivore. Olson reports that Efremov has suggested this species is characteristic of the lower part of the upper Copper Sandstone, the Bashkirian subzone of Zone II.
Larger and more massive than the earlier B. priscus. Olson reports that Efremov has suggested that this species is characteristic of the upper part of the upper Copper Sandstone (Kargalian subzone). King however gives this as the lower or Bashkirian subzone of Zone II, but this would seem to be an error.
Notosyodon gusevi Tchudinov 1968
This is a medium-sized, carnivorous, possibly omnivorous, brithopodid with a massive, heavy skull. Large orbits, Roof of skull very thick in interorbital and parietal areas. The boss on the Parietal bone is high and unusually massive.
genus Syodon Kutorga 1838
A medium-sized, probably omnivorous brithopodid. There are two described species, the differences, according to size and dentition and are not very clearly drawn. The skull high and straight, the orbits large (nocturnal?). The pineal opening is large and situated on a bony mass or boss formed by frontals and parietals (the roof of the skull, behind the snout). The temporal opening is of the "Titanophoneus" type in which the postorbital hone is large and thick and provides an area for origin of part of the superficial adductor musculature, on the outer dermal surface of the skull. This is a characteristic feature of the brithopodines. The dental pattern both in this genus and among the brithopodines as a whole, is highly variable both in the palate and on the jaw margins.
Most of the postcranial remains from the Kamennyi Valley locality are many isolated hones of a small, immature and may merely be young individuals of one of the larger genera. Vertebrae, probably referable to Syodon. indicate that there are very few differences from Titanophoneus, except for smaller size. The limb bones (femora) show the characteristic features of the brithopodines and are somewhat crocodilelike in general aspects. They are slender with ridges and condyles weakly developed, and with a slight curvature. This type of femur is very different to that of its distant pelycosaurian ancestors.
A subfamily of large to very large dinocephalians which are fairly primitive carnivores, with long intermeshing incisors. There is a boss on the angular (rear of the jaw), probably for the attachment of muscles. A stage further advanced than the Brithopidinae.
This taxon is just a convenient "waste basket" for basal Anteosaurinae, as a complement to the monophyletic Anteosaurini. This paraphyletic tribe has absolutely no official taxonomic status (nor should it, I just set it up here). I wouldn't be surprised however if further studies reveal several parallel lineages of these giant mid-Permian carnivores - Anteosaurs, Doliosaurs, Titanophines, all evolving in parallel (rather like the several lineages of Tyrannosaurs at the end of the Cretaceous). Hopson and Barghusen's cladogram has Titanophoneus representing an intermediate stage between the more primitive and basal Brithopodines and the more specialised Anteosaurini. These animals are ever bit as large as the more derived Anteosaurini.
Along with Anteosaurus, Titanophoneus was the largest of the Brithopodids, and clearly played the role of a superpredator in terrestrial tetrapod assemblages. The specimen usually illustrated (above) was found articulated and represents a young animal, with a skull about 26 cm in length. An adult skull would be almost one meter in length. The long snout, the long tail and the short limbs are all primitive, typically Brithopodid features. It is interesting to compare the above drawing with the mount (see top of page), apparently of the same animal. In the photograph the back does not have the giraffe-like slope, and the tail is a lot shorter.Titanophoneus potens Efremov 1938a
A very large carnivorous dinocephalian. The skull is high and narrow. The large pineal opening is situated on a tuberosity formed by the parietals bones on the roof of the skull. The prefrontals (upper side, in front of eyes) are also thickened by tuberosities as is the dorsal (upper) border of the orbit. The palatines (roof of mouth) bear 7-8 teeth, high and nclined backwards, and there are two large pterygoid teeth on the lateral pterygoid flange (side of roof of mouth). The lower jaw is deep. The femur (thigh bone) is relatively more slender than in pelycosaurs, but the pelvic gurdle is vbvery primitive and pelycosaur-like. The gorgonopsia have similiar post-cranial features, but they seem to have a more advanced, less sprawling gait.
This genus was named by Efremov (1954) on the basis of rather fragmentary materials from the Kargalian Mines. Anterior dentitions, partial jaws, part of a palate, a humerus. and a scapula are known. The genus clearly was a large (probable minimum skull length of 50 cm), specialized carnivorous animal related to Titanophoneus. It is from high in the Copper Sandstone, from the later part of Zone II. Efremov notes that it may be equivalent to the Isheevian Complex in age and that, if this is the case, it may not be generically distinct from Titanophoneus, although it is without question specifically distinct, although detailed morphological studies of Orlov (1958) indicated that it is generically distinct. Boonstra, and following him King, include this genus under the Anteosauridae/inae/ini, as distinct from Titanophoneus.
These are very advanced, very large brithopodids. The post-canine teeth are further reduced. Deepening of the post-orbital region of the skull (behind the eyes) producing a larger temporal opening, indicating more muscle mass. There boss on the angular (rear of the jaw) has become very prominant, again, another sign of powerful jaw muscles. These huge animals were clearly formidable preditors.
In the Anteosaurini the pachystosis is taken to extremes. The dorsal (upper) surface of the nasal, frontal, and post-frontal bones (around and between/above the eyes) is thickened and rugose - or "pachyostotic" in the same manner as the tapinocephalines. Nevertheless these animals are two specialised and too late in time to have been the ancestors of the herbivorous tapinocephalines, so it is obvious that these characteristics evolved independently, as part of head-butting behaviour. Boonstra notes that the hip joint and the femur of Anteosaurus is comparable with those of the crocodile and these animals may have had a crawling habit, and in view of the carnivorous dentition, belives them to have been slinking predators. However crocodiles are certainly incapable of head-butting, and in any case don't need to assert their territory in that way; it which is more a terrestrial behaviour.
Doliosauriscus Kuhn 1961(= Doliosaurus Orlov 1958)
This is a large carnivorous dinocephalian, very similiar to the South African Anteosaurus and the Russian Titanophoneus. There are two species of similiar size, but it is not certain the second one belongs in the same genus
Along with Titanophoneus, this is the largest species of brithopodid from Isheevo. According to Olson there is an excellent skull (left), with some restoration and some flattening. The skull is high and straight, the orbits and pineal opening not very large. All dorsal (upper) skull bones thickened with tuberosities, the parietals (in the middle rear) greatly so.
Olson suggests that the crushing may be somewhat less extensive than Orlov's restorations suggest and that the skull was proportionately somewhat lower and broader than that of Titanophoneus. The postorbital bone is very large and forms a strong bar between the orbit and the temporal opening, for the attachment of the jaw musculature. In spite of the large size the skull is typically brithopodid, the basic structure much the same as in Titanophoneus and Syodon
This species is based upon a specimen from Malyi Uran (Malouran). Olson suggests that this specimen is sufficiently different from Doliosaurus yanshinovi that it might well be considered a different genus, related more closely to Titanophoneus
Anteosaurus Watson 1921
As defined by Boonstra, "a genus of anteosaurids in which the postfrontal forms a boss of variable size overhanging the dorso-posterior border of the orbit." On this basis he synonymised six of the seven genera named from the Tapinocephalus zone: Eccasaurus, Anteosaurus, Titanognathus, Dinosuchus, Micranteosaurus, and Pseudanteosaurus. Of these, he says, Dinosuchus and Titanognathus can safely be considered synonyms of Anteosaurus. Eccasaurus, with a holotype of which the cranial material consists of only few typical anteosaurid incisors, appears to be only determinable as to family. The skull fragment forming the holotype of Pseudanteosaurus can best be considered as an immature specimen of Anteosaurus. Micranteosaurus, the holotype of which contains a small snout, was previously considered a new genus on account of its small size but is better be interpreted as a young specimen of Anteosaurus. And likewise, the large number of species attributed to the genus Anteosaurus can also be considered synonyms.
Boonstra still considers as valid the genus Paranteosaurus, which is defined as a genus of anteosaurids in which the postfrontal is not developed to form a boss. This is probably an example of individual variation and hence another synonym of Anteosaurus.
As with the genera, so the species are also mostly synonyms. The oldest species name, A. magnificus, is thus the only valid one. To quote Boonstra again:
"We have 32 skulls of Anteosaurus, of which 16 are reasonably well preserved and on them ten species have been named. To differentiate between the species the following main characters have. been used: the number, size and shape of the teeth, skull size, shape and the nature of the pachyostosis. On re-examination it has become clear that the crowns of the teeth are seldom well preserved; basing the count for the dental formula on the preserved roots is unreliable. as this is affected by age and tooth generation; size of skull is a function of age and also possibly sex; sk~-shape is greatly affected by post-mortem deformation, and the variability in the pachyostosis, which may be specific in some respects, can just as well be the result of...physiological processes. Specific diagnosis consisting of the enumeration of differences of degree in features such as the above can hardly be considered as sufficient indication of the existence of discrete species....A. magnificus thus has the following synonyms: abeli, acutirostrus, crassifrons, cruentus, laticeps, levops, lotzi, major, minor, minusculus, parvus, priscus and vorsteri."
The reason for the synonymy he gives as follows: the holotypes of cruentus, levops, minor, minusculus, and parvus are of immature animals; lotzi and priscus are specifically indeterminable; and in the case of abeli, acutirostrus, crassifrons, laticeps, major and vorsteri because the characters used are either due to post-mortem deformation or individual variation in the degree of pachyostosis. Ironically, a lot of these specific and generic synonyms were named by Boonstra himself, who reversed his earlier decisions later on.
A lineage of short-headed medium-sized to large herbivorous (or partially omnivorous) brithopodids. They seem to have died out by the mid-Capitanian. Olson incorrectly separates Deuterosaurus from the rest of the Brithopodids. Boonstra, and following him King, includes the genus under the Anteosauridae/inae/ini.
Deuterosaurus Eichwald 1860
Apart from two incomplete skulls and some post-crania the remains are very fragmentary. Synonyms: Mneneiosaurus and Uraniskosaurus, both erroneously errected by the Romanian paleontologist Nopcsa in 1928, also Eurosaurus in part.
Diagnosis: Skull (above) nearly as high as long (about 230 mm). Skull thickenings localised in area just anterior to anterior orbital margin. Lower tusks with longitudinal facets on enamel. Postcanine teeth smallish, flattened from side to side. A study of the tooth apparatus morphology revealed an unexpected complexity of crown structure in the palatal teeth. Tibia large with rounded and massive head. As with most early dinocephalians, the femur (thigh bone) is essentially similiar to that of sphenacodont pelycosaurs, although there are a number of differences relating to points of muscle attachment (incipent development of trochanter major)Deuterosaurus biarmicus Eichwald 1860
The holotype teeth are very different from the teeth found in the Deuterosaurus and may belong to a tapinocephaline, possibly UIemosaurus, which is found in the same deposits. The postcranial material may be brithopodid, hence the species is allowed to stand.
|some Links and References|
L. D. Boonstra, "The Fauna of the Tapinocephalus Zone (Beaufort Beds of the Karoo)", Annals of the South African Museum, 56 (1) 1969, pp. 1-73
Dinocephalia after Carroll 1988 - cladogram and genus list, based on Robert L. Carroll Vertebrate Paleontology and Evolution - Mikko K. Haaramo
James A. Hopson and Herbert R. Barghusen, "An Analysis of Therapsid Relationships", in The Ecology and Biology of Mammal-Like Reptiles ed. by Nocholas Hotton III, Paul D. MacLean, Jan J. Roth and E. Carol Roth, Smithsonian Institute Press, Washington and London, 1986, pp.83-106
Christian Kammerer - personal communication
Gillian M. King, "Anomodontia" Part 17 C, Encyclopedia of Paleoherpetology, Gutsav Fischer Verlag, Stuttgart and New York, 1988
A. A. Kurkin, On the Dental Morphology of Deuterosaurus biarmicus Eichw. (Dinocephalia, Synapsida), Paleonotological Journal, Vol. 31, No. 1, 1997
Dr A. H. Müller, Lehrbuch der Paläozoologie, 1968
Everett C. Olson, "Late Permian Terrestrial Vertebrates, USA and USSR", Transactions of the American Philosophical Society, Philadelphia, vol 52 part 2, 1962
Palaeos Page (incorporates some of this material, plus a lot of additional material)