The Vertebrates Moradisaurinae


Captorhinidae: Moradisaurinae

Abreviated Dendrogram
Amniota ├─Synapsida └─┬─Anapsida │ └─Eureptilia ├─Coelostegus └─┬─┬─Thuringothyris │ └─Captorhinidae │ ├─Concordia │ └─┬─Romeria │ └─┬─Captorhinus │ └─Moradisaurinae │ ├─Labidosaurikos │ └─┬─Gecatogomphius │ ├─Kahneria │ ├?─Rothianiscus │ └─Moradisaurus └─Romeriida ├─Paleothyris └─┬─Protorothyrididae └─Diapsida

     Captorhinidae (2)
     Captorhinidae (3)

Taxa on this Page

  1. Gecatogomphius X
  2. Kahneria X
  3. Moradisaurinae X
  4. Labidosaurikos X
  5. Moradisaurus X



Captorhinidae ::: Captorhinus + (Labidosaurus + * : Labidosaurikos + (Gecatogomphius + (Kahneria + Moradisaurus)))

Mid to Late Permian of N Am, EEur, & Afr.

The subfamily Moradisaurinae comprises the most derived captorhinids and forms a monophyletic group. They are opposed to the "Captorhininae", the more basal, mainly single-tooth-rowed forms which closely resemble other generalized amniotes, such as Protorothyris or Hylonomus. The "captorhinines" are a paraphyletic group and therefore this term is only used for comparative purposes.

All moradisaurines are characterized by having multiple rows of teeth in their jaws which virtually form whole tooth batteries. The teeth are positioned on medially extended tooth plates formed by the maxillary and dentary bones. From this follows that these teeth are homologous to the teeth of the single tooth row seen in more basal captorhinids. However dentition on palatal bones, a common trait of basal amniotes, is greatly reduced or even entirely absent in moradisaurines. It has been speculated whether the medial margins of the upper tooth plates were connected to each other by a layer of soft tissue and formed a secondary palate in the living animal.

Because multiple tooth rows, however not in that great extent, also occur in captorhinids that fell outside the moradisaurine clade (e.g. in Captorhinus aguti) it seems that multiple tooth rows have evolved several times within captorhinids.

The teeth itself often show a distinct wear pattern. Wear facets occur just below the tip on both sides of the crown and sometimes reach down to the half of te crown's height. This quite regular wear pattern differs from the more irregular pattern observed in Captorhinus aguti and most likely was generated by the occlusion of opposing teeth of the upper and lower jaw in a way that one tooth row of the upper jaw fitted between two tooth rows of the lower jaw, and vice versa. This, in turn, is suggestive of changes in feeding behavior in the moradisaurines compared to their more generalized "captorhinine" ancestors (however, it is important to note that C. aguti is quite specialized already).

Most conclusive is to assume a herbivorous diet for the moradisaurines. However in most genera no postcranial elements are preserved which could provide evidence for that assumption, such as an expanded, barrel-shaped rib cage, appropriate for carrying an enlarged intestinal tract which would be required for digestion of plant material. Solely in Moradisaurus, the type genus of the subfamily, there are signs for modifications of the postcranial skeleton due to adaptation to herbivory. Its hindlimb is much more massive built than those of the "captorhinines". It resembles strongly that of an edaphosaur or a pareiasaur, both of which are Late Paleozoic, unequivocally herbivorous amniotes, hence this massiveness may not result from allometric scaling anlone. Alternative models of moradisaurine feeding behavior include omnivory or durophagy, the latter meaning that they used their tooth batteries to crush hard shelled invertebrates, such as clams or crabs, to achieve their meat.


Labidosaurikos meachamiStovall 1950

Generic name refers to its similarity to Labidosaurus (note that at that time no other moradisaurine was known). Species named after E. D. Meacham, dean of the College of Arts and Sciences of the University of Oklahoma at that time

In vivo reconstruction of L. meachami

In vivo reconstruction of L. meachami

? Labidosaurikos barkeri Olson 1954

Moradisaurinae : (Gecatogomphius + (Kahneria + Moradisaurus)) + *

Family Captorhinidae

Hennessey Formation (Sumner Group)

Upper part of Clear Fork Group (formerly referred to as "Choza Formation")

Lower Permian : Leonardian

Remains found in Logan County, Oklahoma, USA; Foard County, Texas, USA. Inhabited Anadarko Basin, "Eastern Shelf" of Midland Basin, northwestern Pangaea

Labidosaurikos meachami is a large, multiple-tooth-rowed captorhinid. It is the basalmost member of the subfamily Moradisaurinae. It is known from one single, however almost complete and virtually perfectly preserved skull coming from Lower Permian terrestrial deposits of central Oklahoma.

Scientific History: L. meachami has been discovered as early as in 1939 but has not been named and introduced to paleontology until 1950. Finally a detailed description of the skull has been published in 1995.

Skull: The heavily ornamented skull of L. meachami measures about 28 cm in length. Given that the trunk length in Captorhinus is approximately 3.6-fold the skull length, the overall body length in L. meachami was as much as 1.3 m. L. meachami shows almost the whole range of features which define the moradisaurines. Its snout is, compared to the posterior part of the skull, very narrow. Its dentigerous bones form wide tooth plates equipped with batteries of relatively small subconical teeth. The supratemporal is comparativley large and sculptured. The postparietal is not entirely overlapped dorsally by the parietal and its exposed portion is sculptured as well. Both supratemporal and postparietal contribute to the skull table in a way that the parietal is excluded from the posterior rim of that table. L. meachami, however, differs from the other well known moradisaurine Moradisaurus in retaining a band of small denticles on the posterior egde of the transverse flange ("wing") of the pterygoid. Another difference to Moradisaurus is the lateral wall of the mandible being only modestly bulged, however this bulge is still much more pronounced than in smaller moradisaurines such as Kahneria or Gecatogomphius.

Teeth: The only premaxillary tooth preserved is the largest tooth of the upper jaw and slightly recurved. The anteriormost dentary tooth is the largest of the lower jaw, however, only its base is preserved. The teeth of the maxillary and dentary tooth plates are arranged in six and five, respectively, longitudinal rows in which the teeth of two adjacent rows each alternate resulting in a chessboard-like pattern. Most of these teeth show distinctive wear facets. The teeth of the most labial row are exclusively worn on the lingual side whereas wear in the most lingual row is restricted to the labial side. Almost all teeth of the median rows are worn on both labial and lingual sides. This wear pattern is apparently the result of interdigitation of the tooth rows of upper and lower jaw. Thus it is very likely that the teeth were used for grinding fibrous plants.

A second species(?): A second species of Labidosaurikos, L. barkeri, has been described from the deepest part of the "Choza Formation" (upper part of Clear Fork Group) of North Texas in 1954 but has been questioned as early as 1959. It differs from L. meachami in having one less row of teeth in both maxillary and dentary. The material, however, is fragmentary. Given that the Texas specimens seem to be immature the number of tooth rows could be related to age. Because no further unequivocal difference between L. meachami and L. barkeri is as yet reported a revisional examination of the Texas fossils is needed to verify the validity of L. barkeri.

Refers to data on L. barkeri

DODICK, J.T. and MODESTO, S.P. (1995): The Cranial Anatomy of the Captorhinid Reptile Labidosaurikos meachami from the Lower Permian of Oklahoma. Palaeontology 38 (3): 687-711

OLSON, E.C. (1954): Fauna of the Vale and Choza: 9 Captorhinomorpha. Fieldiana Geology 10 (19): 211-218

SELTIN, R.J. (1959): A review of the family Captorhinidae. Fieldiana Geology 10 (34):461-509

STOVALL, J.W. (1950): A New Cotylosaur from North Central Oklahoma. American Journal of Science 248 (1): 46-54

Zidane 26 May 2008

Gecatogomphius kavejevi Vjushkov & Chudinov 1957

Everett C. Olson (1962) used the western transcription Hecatogomphius in his translation of Vjushkov & Chudinov's (1957) original description of this species. Since then this genus name was used numerous times by non-russian authors.

Generic name means "hundreds of cheek teeth". Species named after the Soviet geologist M.S. Kaveev.

Belebei Formation

Upper Permian : Kazanian

Remains found on the banks of Vyatka River, Kirov District, western Russia. Inhabited Foreland Basin of the Urals, northeastern Pangaea

Gecatogomphius kavejevi is a multiple-tooth-rowed, moradisaurine captorhinid from the western forelands of the Ural Mountains in Russia. It is as yet the best known captorhinid from eurasia and the only recognized species of the genus.

Scientific History: G. kavejevi was discovered in 1955 by the Soviet geologist M. S. Kaveev who found a fragment of a lower jaw at the bank of the Vjatka River in Kirov District. Subsequently this bone was sent to the Academy of Science of the USSR. In 1957 it has been named and published. Since then only one further remain of G. kavejevi, a single fragmentary maxillary tooth plate, came to light.

Description: The dentary is about 8 cm in length. Its lateral wall is sculptured with an irregular pattern of long and deep groves as seen in many other captorhinids. Medially it is widened to form the typical moradisaurine tooth plate. In its anteriormost portion the dentary shows tree caniniform teeth being as twice as large than the teeth of the tooth plate. An alveola at the tip of the bone indicates the former presence of a fourth caniniform. The tooth plate bears more than 40 bulbous teeth arranged in five rows. Similar to Labidosaurikos the teeth of two adjacent rows each alternate and show more or less pronounced wear facets below the apex. An important particularity in G. kavejevi is that the jaw bears signs of resorption pits which is the only occurence of such a feature in moradisaurines so far.

The fragment of the maxillary tooth plate also bears five rows of teeth, showing a wear pattern similar to that of the teeth on the dentary.

Phylogeny: Despite the sparseness of the material preserved G. kavejevi is clearly a moradisaurine, i.e. a member of the most derived clade of the family. A close relationship to the North American representative Kahneria seltina has been postulated, however, since the establishment of modern cladistic methods the latter never was included in relevant analyses.

Ivakhnenko (1990) assigned the horizon of provenance of Gecatogomphius to the Ocher assemblage, a unit of russian non-marine vertebrate biostratigraphy. In Lucas (2006) this assamblage is correlated with the Kazanian stage of global stratigraphy.

DODICK, J.T. and MODESTO, S.P. (1995): The Cranial Anatomy of the Captorhinid Reptile Labidosaurikos meachami from the Lower Permian of Oklahoma. Palaeontology 38 (3): 687-711

IVAKHNENKO, M.F. (1990): Early Permian Elements of Faunal Assemblages of Tetrapods from Eastern Europe [Раннепермские элементы фаунистических комплексов тетрапод Восточной Европы]. Paleontologicheskii Zhurnal 1990 (2): 102-111 [russian]

LUCAS, S.G. (2006): Global Permian tetrapod biostratigraphy and biochronology. pp. 65-93 in SPENCER G. LUCAS et al. (eds.): Non-Marine Permian Biostratigraphy and Biochronology. Geological Society, London, Special Publications, vol. 265. The Geological Society, London

OLSON, E.C. (1962): Late Permian Terrestrial Vertebrates, U.S.A. and U.S.S.R. Transactions of the American Philosophical Society, ns 52 (2): 1-224

VJUSHKOV, B.P. and CHUDINOV, P.K. (1957): Discovery of a Captorhinid in the Upper Permian of the USSR [Открытие Kaпторинид в верхней Перми CCCP]. Doklady Akadademii Nauk SSSR 112 (3): 523-526 [russian]

Zidane 25 May 2008 (PDT)

Kahneria seltina Olson 1962

Genus named after the discoverer of the type locality (today called Kahn Quarry), Jack Kahn, staff member of the University of Chicago and one of E.C. Olson's collaborators at that time. Species named after the paleontologist Richard J. Seltin.

San Angelo Formation (Pease River Group)

Middle Permian : Upper Leonardian or Lower Guadalupian

Remains found in Knox County, Texas, USA. Inhabited "Eastern Shelf" of Midland Basin, northwestern Pangaea

Kahneria seltina is an average-sized poorly known representative of the multiple tooth-rowed captorhinids. It is known from tooth plates of lower and upper jaws, skull fragments and few scrappy postcranial material coming from terrestrial red beds of the Middle Permian of North Texas. The tooth plates bear five rows of more or less conical teeth. K. seltina is, without much doubt, a member of the moradisaurines.

The problem of exact stratigraphic position of San Angelo Formation has still not entirely been solved. In official geological maps of the USGS or the Texas Bureau of Economic Geology the San Angelo Formation is assigned to the Guadalupian series.

OLSON, E.C. (1962): Late Permian Terrestrial Vertebrates, U.S.A. and U.S.S.R. Trans. Amer. Philos. Soc., ns, 52(2), pp. 1-224

Zidane 25 May 2008

Moradisaurus grandis Taquet 1969

Generic name means "reptile of Moradi". Specific epithet means "large"

Moradi Formation (Izégouandane Group)

Upper Permian

Remains found near Tchimozenog, Agadez District, northern Republic of Niger. Inhabited Iullemmeden Basin, central Pangaea.

Moradisaurus grandis is the largest and most derived known multiple tooth-rowed captorhinid so far. Moradisaurus is type genus of the subfamily Moradisaurinae and M. grandis is the only species currently referred to that genus. It is known from both skull and postcranial remains.

Its skull measures more than 40 cm in length and width, and is covered with a heavy ridge and pit sculpture. Compared with the ratio of skull/trunk length in Captorhinus its overall body length might have been about 1.8 m. The wide tooth plates of its jaws are equipped with 11 rows of relatively small, subconical teeth and the side walls of the massive mandible are strongly laterally bulged. The posterior portion of the skull is very wide and the flanges of the pterygoid have a large surface providing space for the attachment of the jaw musculature. Unfortunately the state of preservation in the skull found seems not to allow the determination of the exact shape and relationships of the bones in both skull roof and palate. Nevertheless there is hope that further investigations and collections will fill this gap of knowledge.

Besides the skull also the hindlimb of M. grandis has been described in detail. Leg and foot are, in contrast to other multiple tooth-rowed forms, very massive and built in a way suggesting that M. grandis was not a fast runner. The femur resembles more that of an edaphosaur or a pareiasaur both of which are large herbivores of the Late Paleozoic. Granted that M. grandis was a herbivore too, and that is what is assumed for the large multiple tooth-rowed captorhinids, the changes in limb proportions seem quite plausible and related to adaptation to herbivory.

M. grandis lived on a river plain in the central region of the supercontinent Pangaea. This plain was periodically affected by pyroclastic flows, which, accompanied with stream-action, apparently played a significant role in burial and preservation of the fossils found in the region today.

O'KEEFE, F.R., SIDOR, C.A., LARSSON, H.C.E., MAGA, A. and IDE, O. (2005): The Vertebrate Fauna of the Upper Permian of Niger - III, Morphology and Ontogeny of the Hindlimb of Moradisaurus grandis (Reptilia, Captorhinidae). Journal of Vertebrate Paleontology, 25(2), pp. 309-319

RICQLES, and TAQUET, P. (1982): La Faune de Vertébrés du Permien Supérieur du Niger I. Le Captorhinomorphe Moradisaurus grandis (Reptilia, Cotylosauria) - Le Crane. Ann. Paléont., 68(1), pp. 33-106

TAQUET, P. (1969): Première découverte en Afrique d'un Reptile Captorhinomorphe (Cotylosaurien). C. R. Acad. Sc. Paris D, 268(1), pp. 779-781

Zidane 10:57, 25 May 2008

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