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Family Estemmenosuchidae

With the decline of the Kungurian and Ufimian Caseids, the herbivorous Estemmenosuchids took over the role of as top herbivore. These were massive, clumsy-looking animals, with a sprawling posture, and reaching the size of an adult bull, although some types were smaller.

The skull is high and massive. The creature is equipped with several bizarre set of large horns projecting both upwards and outwards, probably used for intra-specific display. There are five large teeth in the maxillae (upper jaw bone), rather short canines, and at least twenty small and uniform post-canines. Each tooth has a swollen crown and a sharp, laterally compressed serrated apex. There are also numerous small teeth on the palate (vomers, palatines and pterygoids). The reduced side teeth , with a bulky body for digesting volumes of plant food indicate a herbivores lifestyle, despite the large canines. Vegetable matter was grasped with the strong front teeth and swallowed without chewing, as the weak and thin side teeth only served to keep food in the mouth. These animals would nevertheless have taken carrion when they could find it, as the great force exerted by the chisel-like front teeth could cut up meat quite easily.

As with the Tapinocephalids of the early Capitanian epoch, a number of types are known, and it seems like for a short time they constituted a successful evolutionary radiation. Connections are sometimes suggested with the Styracocephalidae, but in the Estemmenosuchids the 'horns' situated on the frontals, and directed dorsally, whereas in the Styracocephalidae the 'horns' are formed by the tabular and directed posteriorly. Otherwise their features very similar to those of the Styracocephalidae. It is not possible to say tehrefore whether the relationship is one of ancestor-descendent or simply evolutionary convergence due to similiar lifestyle (although the different bones forming the horns would suggest to me the latter).

The remains of Estemmenosuchus have been found in a channel flood deposit, indicating that they probably frequently lowland and marshy areas.

Estemmenosuchids were probably at least partially endothermic (warm-blooded), although body temperature was also maintained by their large size

Ecological niche: large to very semi-aquatic to terrestrial herbivores
Modern equivalent: hippo???
Time: middle Permian
Distribution: although so far fossil remains are known only from eastern Russia it is likely these animals had a much wider, probably worldwide ( link to palaeos com Pangea) distribution
preferred food: plants
length: from 1.5 to 4.5 meters
weight: 50 kg to 1500 kg
Metabolism: partially endothermic? gigantotherms (Homeotherms)
Predators: Eotitanosuchids, Brithopodids
Ancestor: basal dinocephalian or proto-Phthinosuchus-like ancestor?)
Replaced: Large Caseids
Replaced by: Titanosuchids and Tapinocephalids
Descendents: Styracocephalids?
Taxonomic status - Family

Family Estemmenosuchidae Tchudinov 1960


Estemmenosuchus uralensis Tchudinov, 1960

Locality: Ocher, Perm Region, eastern European Russia
Age: Upper Kazanian Substage (= Late Permian), about 255 million years ago - "Zone I" - (late? Roadian or early link to palaeos com Wordian epoch)
Meaning of name: "Crowned crocodile of the Urals"
elements of skull and skeleton
size: about the size of a rhinoceros

Estemmenosuchus mirabilis Tchudinov, 1968

photo by Gondwana Studios

Locality: Ocher, Perm Region, eastern European Russia
Age: Upper Kazanian Substage (= Late Permian), about 255 million years ago - "Zone I" - (late? Roadian or early link to palaeos com Wordian age)
Meaning of name: "Miraculous Crowned crocodile"
material: skull, lower jaw and vertebrae
size: about the size of a rhinoceros This skull was found among an assemblage of many complete skeletons and skulls in a concentrated accumulation. It is closely related to Estemmosuchus uralensis. This species is less common than E. uralensis but has more spectacular "horns"


Molybdopygus arcanus Tchudinov 1964

Known remains (Holotype): pelvic girdle in articulation with the second and third sacral vertebrae
Location: Bolshoi Kitiak, Malmych, Kirov, Russia
Age Lower Tatarian Substage; "Zone II" (= Middle Permian) - Late Wordian or early Capitanian age

Known from an exceptionally thick-walled and massive pelvic girdle, this specimen was originally considered brithopodid. This genus is distinguished from Estemmenosuchus by the thicker walled, more massive pelvis, the presence of flat facets at the posterior end of the acetabulum and a high pubo-ischiadic symphysis. No skull is known


Anoplosuchia tenuirostris Tchudinov 1968b

Known remains Holotype: incomplete skeleton and skull
Location: Ochersky area, near Eshovo, Perm region, Russia
Age Upper Kazanian Substage; "Zone I" (= Late Permian) - (late? Roadian or early link to palaeos com Wordian age).

A medium sized estemmenosuchid with a comparatively narrow skull. Preorbital region long, rather low and broad; postorbital short, weak, broad and high. Preorbital region without excrescences or thickening except in thc posterior nasal region. Outer edge of jaw in region of canine bears weak boss. Incisors more or less equal in size to canines.


Zopherosuchus luceus Tchudinov 1983

Known remains poorly preserved skeleton and incomplete skull
Location: Ochersky area, near Eshovo, Perm region, Russia
Age Upper Kazanian Substage; "Zone I" (= Late Permian) - (late? Roadian or early link to palaeos com Wordian age).

A relatively small estemmenosuchid about 1.5 meters long. Frontal and parietal bones of the skull panicularly thickened.

some printed references some Links and References Web links

Great Russian Dino Expo site Estemmenosuchus uralensis
Estemmenosuchus mirabilis

web pagephotographsEstemmenosuchus uralensis - same content as preceeding page, but bigger photo

printed referenceGillian M. King, "Anomodontia" Part 17 C, Encyclopedia of Paleoherpetology, Gutsav Fischer Verlag, Stuttgart and New York, 1988

printed referencePeter K. Chudinov, "New Facts about the Fauna of the Upper Permian of the USSR", Journal of Geology, 1965, 73:117-30

cladogramDinocephalia after Carroll 1988 - cladogram and genus list, based on Carroll (see next reference) - Mikko K. Haaramo

printed referenceRobert L. Carroll Vertebrate Paleontology and Evolution - W. H. Freeman and company, New York, 1988

web pagephotographsStars of the Show - includes Estemmenosuchus

Therapsida main page
link to palaeos com Permian Period Therapsida Dinocephalia

link to palaeos com Palaeos link to palaeos com Palaeos Page (incorporates some of this material, plus a lot of additional material)

Kheper index page
Palaeo index page
Therapsida main page

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page by M.Alan Kazlev
page uploaded 25 July 2000. Reposted and last modified 1 September 2005, links updated 16 January 2010