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A capitosaurid labyrinthodont fromthe Early Scythian of TasmaniaJ.W. Cosgriff a & S.L. DeFauw aa Department of Biological Sciences , Wayne State University ,Detroit, Michigan, 48202, U.S.A.Published online: 27 Nov 2008.

To cite this article: J.W. Cosgriff & S.L. DeFauw (1987) A capitosaurid labyrinthodont from theEarly Scythian of Tasmania, Alcheringa: An Australasian Journal of Palaeontology, 11:1, 21-41,DOI: 10.1080/03115518708618977

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A capitosaurid labyrinthodont from the Early Scythian of Tasmania J. W. COSGRIFF AND S. L. DEFAUW

COSGRIFF, J. W., & DEFAvw, S. L., 1987:03:30. A capitosaurid labyrinthodont from the Early Scythian of Tasmania. Alcheringa 11, 21-41. ISSN 0311-5518. Cranial fragments pertaining to a capitosaurid labyrinthodont from the Early Scythian

Knocklofty Formation of Tasmania are described. They are referred, with question, to the genus Parotosuchus Otschev and Shishkin 1968. Recent literature dealing with the systematics, morphology and palaeobiogeography of the Capitosauridae, a family widely dispersed over Pangaea during several Triassic intervals, is reviewed. It is recommended that Wetlugasaurus be retained in synonymy with Parotosuchus. J. W. Cosgriff and S. L. DeFauw, Department o f Biological Sciences, Wayne State University, Detroit, Michigan, U.S.A. 48202; received 9 July 1984.

Key words: Labyrinthodontia, Early Triassic, Tasmania, Knocklofty Formation, systematics.

TH E CRANIAL fragments to be described in this paper all pertain to capitosaurid labyrinthodonts. Since the various pieces do not exhibit diagnostic features at a low taxonomic level, they are referred to the genus Paro tosuchus with question as this is the central and most commonly reported Early Triassic genus of the family. At any rate, some of the fragments clearly indicate an affinity with either Paro tosuchus or with a genus closely related to it.

The provenance of ?Parotosuchus sp. is the Early Triassic Knocklofty Formation, a terrestrially deposited unit which outcrops extensively across southeastern Tasmania. The type section on Mount Knocklofty, in West Hobart , measures 180 m in thickness minimally and is informally divided into three members. The lower member (c. 90 m) and the upper member (c. 50 m) are mainly composed of massive sandstones. The middle member (c. 40 m) is extremely varied in lithology but is dominated by varicolored siltstones and shales. For detailedaccounts of the lithology, stratigraphy and depositional environment of the Knocklofty Formation see Banks et al. (1978), Banks & Naqvi (1967) and Cosgriff (1974). The last reference provides accounts of the fossil vertebrate localities with a faunal list for each.

Most of the fragments of ?Parotosuchus sp. were collected at the Old Beach locality.

0311/5518/87/010021-21 $3.00 © AAP

However, two skull roof pieces derive from the Midway Point locality and an isolated palatal fragment was found in a tumbled sandstone block on the edge of Old Beach Road at a point 600 m north of the Old Beach locality. All three of these sites lie in the lower member. Banks et al. (1978) provide a thorough account of the Old Beach locality that describes its physical properties, discusses the total recovered fauna and flora and attempts a reconstruction of the living community and its environment.

The productive level at Old Beach was a pebble conglomerate lens, exposed in a former cut of the Old Beach Road, which extended about 30 m along the cut face and penetrated roughly 7 m into the former hill slope. The lens, as exposed, measured 0.5 m at the thickest central part and diminished to a feather edge at each end. It represents the channel fill of a stream which meandered across the lowland basin in southeastern T asm an ia dur ing the Ear ly Triassic . Excavations carried out by the senior author at Old Beach, at intervals from 1964 to 1971, yielded a large varied collection of bones and bone fragments from fishes, amphibians and reptiles. In 1975 the Old Beach Road was widened and virtually all of the remaining lens was removed. The spoil, when broken down, produced much additional bone, greatly augmenting the previous collections and elevating Old Beach to its position as the most productive of all of the fossil vertebrate localities in the Knocklofty Formation.

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22 J.W. COSGRIFF AND S. L. DEFAUW ALCHERINGA

?Parotosuchus sp. adds a fif th temnospondyl taxon to the vertebrate assemblage 6f the Knocklofty Formation, the other four having been described by Cosgriff (1974). Additional faunal elements include three actinopterygian and two sarcopterygian fishes (Dziewa, 1980) and a single proterosuchian reptile (Camp & Banks, 1978).

The vertebrate assemblage from the Knocklofty Formation is stratigraphically positioned in the lowermost Triassic, in the interval informally termed the 'AI' horizon by Cosgriff (1984). This designation derives from Romer's (1975) division of the vertebrate succession of the Triassic into 'A', 'B' and 'C' faunas. In a very rough way, 'A' is equivalent to the Scythian, 'B' to the Anisian and Ladinian, and 'C' to the Carnian and Norian. In the modification of Cosgriff (1984), 'A' is subdivided into 'AI ' , with the Lystrosaurus Zone of South Africa as its type assemblage, and 'A2' with the overlying Cynognathus Zone of South Africa as its type assemblage. Using a composite of land vertebrate, marine invertebrate and pollen evidence, the 'AI ' horizon is correlated with: the Early Scythian; the Induan and lower Olenekian stages of Kiparisova & Popov (1956, 1964); the Griesbachian, Dienerian and Smithian stages of Tozer (1967); and the Otoceratan, Gyroni- tan, Flemingitan and Owenitan divisions of Spath (1935). In addition to the land vertebrate assemblages from the Lystrosaurus Zone and the Knocklofty Formation, the 'AI ' horizon also includes those assemblages from the Fremouw Formation of Antarctica~ the Middle Sakamena Group of Madagascar', the Panchet Formation of India, the ArCadia Formation and the Blina Shale of mainland Australia, the Vetluga Series of European U.S.S.R., the Wordy Creek Formation of Greenland and the Sticky Keep Formation of Spitzbergen, Svalbard. All of these, with the exception of the Panchet Formation, include either species of Parotosuchus or species of closely related genera.

The material reported here is housed in the Department of Geology, University of Tasmania (UTGD) and in the palaeontological collections of Wayne State University (WSUPC).

Descriptive palaeontology Family CAPITOSAURIDAE Watson 1919 Although limited to the Triassic, the Capitosauridae span almost the entire stratigraphic extent of this system. The first representatives, including the material reported in this paper, derive from the 'AI ' horizon of the Scythian (Cosgriff, 1984) and the last are found in such Norian deposits as the upper part of the Keuper Group in western Europe (Welles & Cosgriff, 1965).

Capitosaurids were temnospondyls which reached a comparatively large body s~ze. Indeed, some are among the largest amphibians in the fossil record. The skeleton of Paracyclotosaurus davidi Watson 1958, from the Middle Triassic Wianamatta Group ~ of New South Wales, measures c. 225 cm in length, and the fragmentary cranium of Parotosuchus dirus Chernin 1978 perhaps represents an even larger animal. These were crocodiloid in body proportions and, very likely, in habits as well. Available taphonomic evidence, summarized by Cosgriff & Hammer (1983), is consonant with such an interpretation as their remains almost always derive from sediments deposited under fluviatile or lacustrine conditions. Chernin & Cruickshank (1978) have characterized the capitosaurids as mid-water feeders. In contrast, Otschev (1966, p. l l5)described these aquatic predators as passive, benthonic 'living traps'.

Watson (1919, 1962), in two classic treatises on evolut ionary trends in the Labyrinthodontia, established the phyletic derivation of the Capitosauridae as lying somewhere within the Rhinesuchidae, a Late Permian group known mainly from the lower portion of the Karoo sequence in South Africa. The most common and best documented genus is the family type, Rhinesuchus Broom 1908, from the Tapino- eephalus, Cistecephalus and Daptocephalus Zones (Kitching, 1978). Differences in the relative development of portions of the skull and lower jaw outlined by Watson (1919, 1962) and Romer (1947) constitute the only consistent distinctions between the Rhinesuchidae and Capitosauridae. Uranocentrodon senekalensis (Van Hoepen, 1911), from the Lystrosaurus Zone of South

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A L C H E R I N G A T A S M A N I A N C A P I T O S A U R I D 23

Africa, appears to be a morphologic intermediate between Rhinesuchus and such Early Triassic genera as Parotosuchus, however, it is stratigraphically too high to be an annectant form (Cosgriff, 1972).

The two central and key genera of the Capitosauridae are Parotosuchus of the Early

(Scythian) and Middle (Anisian) Triassic and Cyclotosaurus of the Middle (Ladinian) and Late (Carnian and Norian) Triassic. Each of these encompasses a large number of species, is widely dispersed over the modern continental areas of the world and has been extensively described and analysed.

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Fig. 1. Out l ine o f a genera l i zed p a r o t o s u c h i a n skull r o o f s h o w i n g the pos i t ions o f d e r m a l f r a g m e n t s , U T G D 9 5 7 5 0 ( includes po r t i ons o f max i l l a ry , l ac r imal , p r e f ron t a l a n d j u g a l bones) a n d U T G D 9 5 3 8 8 ( includes p o r t i o n s o f t a b u l a r , p o s t p a r i e t a l , s u p r a t e m p o r a l a n d s q u a m o s a l bones) . I nd iv idua l b o n e f r a g m e n t s have been p r o p o r t i o n a t e l y sca led . A b b r e v i a t i o n s fo r all f igures : A n g = a n g u l a r ; a . p = a l a r p rocess ; C = c o r o n o i d ; c . m = c r i s ta muscu la r i s ; c . r = con i ca l recess; c . t = cr is ta t e rmina l i s ; c . t . e = cr i s ta t a b u l a r i s ex te rna ; c . ty = cr is ta t y m p a n i c a ; c o . a - a n t e r i o r c o m m i s s u r e ; Den = d e n t a r y ; Ec = e c t o p t e r y g o i d ; Eo = exocc ip i ta l ; f. = f o r a m e n ; f . a . c - in te rna l c a r o t i d a r t e r y f o r a m e n ; f . ch . t . e = external c h o r d a t y m p a n i f o r a m e n ; f .ch . t . i = in ternal c h o r d a t y m p a n i f o r a m e n ; f . m . p - pos te r ior m e c k e l i a n f o r a m e n ; = f a . a = a r t i c u l a r facet ; f o . a d = a d d u c t o r fossa ; Fr = f r o n t a l ; lc = i n t e r c o r o n o i d ; Ju j u g a l ; L a = lac r imal ; m. l = labia l musc le inse r t ion g roove ; M x = maxi l l a ry ; Na = nasa l ; P = par ie ta l ; p .h = h a m a t e process ; p . p o c = p o s t c o n d y l a r process ; p . p r c = p r e c o n d y l a r process ; p . r a = r e t r o a r t i c u l a r p rocess ; P a = p r ea r t i cu l a r ; Pc = p r e c o r o n o i d ; P f = p o s t f r o n t a l ; PI = pa la t ine ; p l . r = pa l a t i ne r a m u s ; P m = p remax i l l a ry ; P o = pos to rb i t a l ; P o s = pos t sp l en ia l ; P p = pos tpa r i e t a l ; P r f = p r e f r o n t a l ; Ps = p a r a s p h e n o i d ; Pt = p t e rygo id ; Q = q u a d r a t e ; q . r = q u a d r a t e r a m u s ; Q u j = q u a d r a t o j u g a l ; s . io = i n f r a o r b i t a l cana l ; s. j = juga l cana l ; s . so - s u p r a o r b i t a l cana l ; s . t = t e m p o r a l cana l ; Sa = s u r a n g u l a r ; Sp = splenial ; Sq = s q u a m o s a l ; St = s u p r a t e m p o r a l ; T = t a b u l a r ; Vo = v o m e r .

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24 J. W. COSGRIFF AND S. L. DEFAUW ALCHERINGA

Parotosuchus Otschev and Shishkin 1968

The generic designation, Parotosaurus Jaekel 1922, wag changed to Parotosuchus by Otschev & Shishkin (in Kalandadze et al., 1968) as the former name was found to be preoccupied. In the following text, where species of Parotosuchus are mentioned, these were in most cases originally placed in the genus Parotosaurus. Carroll &Winer (1977) list all of the described species up to that year. The junior author (S.L.D.) has revised and updated that portion of the aforementioned list pertaining to the second radiation of temnospondyl amphibians which extended from the Late Permian to the Early Jurassic. The genus Parotosuchus ranges from earliest Scythian ( 'AI ' horizon) to the Anisian and its geographic distribution, on a modern continental configuration, includes Africa, Australia, Eurasia and North America.

Parotosuchus is primarily distinguished from Cyclotosaurus and certain other genera of the Middle and Late Triassic by particulars of the tympanic region of the skull roof. In Parotosuchus, the tympanic membrane was stretched across a posteriorly open otic notch. In Cyclotosaurus, the tabular and squamosal bones of the skull roof contact each other forming a complete encirclement of the tympanum, converting the notch to a foramen. Not all open-notched capitosaurid forms of the Early Triassic have been placed in the genus Parotosuchus. The status of these other taxa is discussed in a section which follows the description of the new material from Tasmania.

?Parotosuchus sp. (Figs 1-6)

Material available for study. From Old Beach locality: skull roof fragments UTGD95750, 95388 and 95699; pa la ta l f r a g m e n t UTGD95385; and lower jaw fragments UTGD95384, 95395 and 95677. From site north of Old Beach locality: palatal fragment WSUPC1102. From Midway Point locality: skull roof fragments UTGD85745 and 85746.

Skull roof fragments. UTGD95750 (Figs 1, 2A) is a rather sizeable, although waterworn, fragment from the left side of the skull roof.

Dermal elements include portions of the maxillary, lacrimal, prefrontal and jugal. These bones vary in thickness from 2 mm (prefrontal, lacrimal and jugal) to 7 mm (the lateral edge of the maxillary). Sutural contacts range f rom s inuous to m o d e r a t e l y interdigitated.

Overal l , the dermal scu lp ture o f UTGD95750 resembles the reticulate pattern observed in o the r members o f the Capitosauridae, although sculpture of this general type is also seen in the families Benthosuchidae and Trematosauridae. The ornament consists of a system of rather low relief (approximately 0.5 mm in height), round-crested ridges separated by grooves (measuring 1 mm across) and pits (1-2 mm in width). Proximal to the ossification centres of each bone, the ridges bear low cross-bridges, thus creating a transition series ranging from circular-equilateral pits to oblong cells to sinuous grooves. The radiating ridges are quite uniform in breadth and do not exceed the width of the grooves.

The infraorbital canal varies moderately in width and depth, being most deeply incised in the region of the lacrimal flexure. It ranges in width from 2.5-4 mm and is interrupted at several points along the length of the flexure by narrow ridges which disrupt the continuity. This septate condition of the lateral line canals has been noted in Parotosuchus (Jaekel & Philippi, 1903) and Cyclotosaurus (Paton, 1974).

The remaining portion of the maxillary forms the lateral edge of this skull roof fragment. Aside from a few areas bearing irregular striations, the rest of the bone surface is quite smooth. The 'sculpturing' observed is presumably the result o f postmortem abrasion as there are no definite sulci or pits, just irregularly spaced ledges of bone. The maxillary's ventrolateral edge carries a row of variably sized peg-like teeth. Small, semicircular embayments occur at various lengths just lateral to the marginal tooth row. The maxillary adjoins the lacrimal along a sinuous suture in the infraorbital canal and is overlain by the jugal just posterior to the lacrimal.

The lacrimal is nearly complete. The sigmoid loop of the infraorbital canal

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A L C H E R I N G A TASMAN1AN C A P I T O S A U R I D 25

traverses the anterior portion of this bone and is superimposed on the ossification centre. Pits comprising the ossification centre of this element are larger and of variable shape, more so than any other component of this fragment . Radiating, sinuous ridges interconnected by arcuate cross-bridges ornament the remainder of the lacrimal. Anteroposterior elongation of this bone is dominant; lateral expansion, as indicated by sculpture, is quite minimal.

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Approximately the anterior half of the jugal is present on UTGD95750. The ossification centre is located along the lateral edge of the bone, partially obscuring the shallow trough of the infraorbital canal in this region. Expansion occurs along the anterior, medial and posterior borders. Compared with the other dermal elements of this fragment, the low ridges on the jugal are more sinuous and bifurcate peripherally. Cross-bridges are irregularly spaced and, overall, rather poorly developed.

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Fig. 2. ?Parotosuchus sp. dermal roof fragments. A, a latex peel of UTGD95750, dorsal view. B, C, left tabular (UTGD85745) in dorsal and ventral views. D,. E, left tabular horn (UTGD85746) in dorsal and ventral views. F, UTGD95388, dorsal view. G, UTGD95699, dorsal view. UTGD85745 and 85746 have been enlarged to twice natural size (bar scale equals 0.5 cm). The bar scale equals 1 cm for remaining dermal roof fragments (UTGD95750, 95388 and 95699).

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26 J.W. COSGRIFF AND S. L. DEFAUW ALCHERINGA

The anterolateral corner of the prefrontal is intact. A portion of its ossification centre lies at the posteromedial corner of the fragment. Sinuous ridges radiate laterally and anteriorly indicating moderate to relatively extensive amounts of growth in these directions, respectively.

UTGD95750 pertains to the Capitosauridae and, perhaps, to the genus Parotosuchus based on the following combination of features: 1. sculpture pattern; 2. arrangement and general proportions of dermal elements; and 3. pronounced Z-shaped curve in the lacrimal region of the infraorbital canal. In regard to the last character, however, a flexure of this configuration is also seen in benthosuchids.

Additional dermal roof fragments from Old Beach include UTGD95388 (Figs l, 2F) and UTGD95699 (Fig. 2G). UTGD95388 is composed of the following elements: part of the squamosal, the posterior corner of the supratemporal, a sliver of the postparietal, and the tabular, intact except for an oblique slice missing from its tip. The same elements comprise UTGD95699 with the exception of the missing distal tip of the tabular horn. The squamosal borders the tabular anterolaterally and contacts the supratemporal which meets the anterior border of the tabular. The postparietal adjoins the tabular anteromedially. Both specimens exhibit moderately interdigitated sutures of the tabular with the squamosal, supratemporal and postparietal. The contacts among portions of the latter three bones, however, are not as clearly defined and may involve squamous overlap.

Surficial sculpture on these specimens varies from element to element. Both tabulars display a deeply punctate pattern. The ornament on the remaining elements is not as conspicuous; this may be attributed, in part, to postmortem abrasion. In UTGD95388, the posteromedial corner of the squamosal, as preserved, bears faint traces of elliptical pits on its surface. The remaining portions of the supratemporal and postparietal on this specimen are so badly splintered that sculpturing cannot be discerned. UTGD95699 exhibits a weakly developed series of elliptical pits on the supratemporal and pits as well as

shallowly incised oblong cells are evident on the postparietal. The portion of the squamosal remaining, which defines the inner edge of the otic notch, bears no evidence of sculpturing.

Tabular horns are well-developed and, as reconstructed from the configurations of UTGD95388 and 95699, jut posterolaterally from the skull deck. These bony projections are roughly triangular in outline, tapering to blunt apices distally. Both specimens possess a prominent ventral keel termed the crista tabularis externa by Bystrov & Efremov (1940). It represents one of a system of five ridges recognized by the authors on the tabular bones of Benthosuchus sushkini. A maximum of three ridges has been reported for parotosuchians by Howie (1970). She described the orientations of these tabular ridges on P. pronus but did not name them, so the terminology established by Bystrov & Efremov (1940) is used here. The presence of additional ridges on UTGD95388 and 95699 cannot be confirmed as much of the ventral surface of these two fragments remains embedded in the matrix.

Dermal roof elements from Midway Point include an isolated tabular horn (UTGD85746, Fig. 2D, E) and a nearly complete tabular bone (UTGD85745, Fig. 2B, C); both were tentatively designated as parotosuchian by Warren (1980). Surface sculpture is deeply punctate over most of UTGD85746, but has been eroded to shallow pits on UTGD85745. The distal ends of both specimens bear longitudinally aligned, elongate pits.

As previously mentioned, each tabular horn is roughly conical in shape and possesses a distinctive ventral keel. The crista tabularis externa as well as the crista terminalis ~re evident on both of these specimens. The crista tabularis externa, which runs along the paroccipital process and continues distally to the apex of the tabular horn, is the more conspicuous of the two and has been suggested as the site of insertion for the m. cleidomastoideus (Howie, 1970). This ridge is flanked laterally by a lower ridge, the crista terminalis, which extends from the base of the paroccipital process to the tip of the tabular horn. UTGD95745, however, clearly displays two additional ridges: the first extends from the base of the paroccipital process and arches

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ALCHERINGA TASMANIAN CAPITOSAURID 27

anteromedially; the second lies posterior and medial to the crista tabularis externa and appears to be confluent with the ridge which runs along the posterior edge of the postparietal. Bystrov & Efremov (1940) term these the crista tympanica and the crista muscularis, respectively. The tabular horn of UTGD85745 curves posteriorly instead of jutting straight out posterolaterally as in the other specimens available for study. Tabulars curved in a similar manner have been noted in P. helgolandicus (Schr6der, 1913, pl. 16; Jaekel, 1922, pl. 1), P. haughtoni (Broili & Schr6der, 1937, fig. 2) and P. gunganj (Warren, 1980, fig. 3A).

All features of the tabulars noted here are consonant with the construction of this element in capitosaurid genera with open otic notches and, more specifically, they bear close resemblance to the tabulars of various species of Parotosuchus. There is, however, the possibility that more than one species is represented.

Ventral skull fragments. Palatal fragment UTGD95385 (Figs 3, 4A, B) from Old Beach is part of the left upper jaw and illustrates the complex sutural relationships of the jugal, maxillary, ectopterygoid and pterygoid. The alar process of the jugal (a horizontal palatal extension of this bone) is overlain by a narrow, posterior extension of the maxillary and by the ectopterygoid. This thin sliver of the maxillary adjoins the ectopterygoid medially and rests in a bony trough formed by the medially-inclined lateral edge of the ectopterygoid and the laterally-inclined slope of the alar process. Superficially, its contact with the ectopterygoid-jugal suture is also weakly interdigitated anteriorly. The posterior edge of UTGD95385 shows a squamous overlap of the ectopterygoid on the jugal, A thin slip of the palatine ramus of the pterygoid contacts the medial edge of the ectopterygoid in a simple, planar suture. The jugal interlocks along the lateral edge of the specimen with a fragment of the quadratojugal.

The jugal is a prominent bone, although only a fraction of its lateral and palatal aspects are represented in UTGD95385. A portion of the infraorbital canal, including the jugal

flexure, runs along the lateral edge of the skull roof and encloses a patch of ornamented bone. Posterior to the jugal flexure, surface sculpture has been removed by abrasion but a faint trace of the jugal canal is evident. The jugal and quadratojugal unite near the posterolateral edge of the fragment along a deeply interdigitated, arcuate suture. Just

benea th the infraorbital canal, the ventral edge of the jugal is protracted forming a narrow ridge which buttresses the lateral edge of the maxillary. This ridge gradually flattens out posterior to the jugal flexure.

The maxillary, in this region, is a narrow, tooth-bearing strip of bone. Typically, the maxillary terminates at the level of the subtemporal fenestra but it has been broken well in advance of this point in UTGD95385. " Its slightly raised ventrolateral edge renders it comma-shaped in cross section. The teeth are roughly circular in basal outline and rest in shallow sockets. Ten tooth pits are evident in this fragment, only four of which contain the broken bases of erupted teeth. The pulp cavities thus exposed are surrounded by plicated enamel.

Only a narrow band of the ectopterygoid remains; its medial edge is underplated by a thin, unornamented flange of the pterygoid. The ventrolateral edge is raised creating a wedge-shaped cross section similar to that of the maxillary. Sixteen tooth pits are present; five contain the broken remains of implaced teeth. Compared to the maxillary teeth, those borne on the ectopterygoid are, for the most part, larger in dimension and more varied in shape. Newly erupted tips as well as the basal remnants of shed teeth are also evident.

WSUPCll02 (Figs 3, 4C, D), from north of Old Beach, is a poorly preserved palatal fragment from the left side of a rather large individual with an estimated skull length of c. 40 cm. The specimen consists of approxi- mately one half of the basal plate of the parasphenoid, the body of the pterygoid with remnants of both palatine and quadrate rami and most of the exoccipital bone. The position of the fragment on a generalized skull outline is portrayed in Fig. 3.

The basal plate of the parasphenoid adjoins the pterygoid laterally and the exoccipital

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28 J . W . C O S G R I F F AND S. L. D E F A U W A L C H E R I N G A

posteriorly. The rather sinuous, deeply interdigitated parasphenoid-pterygoid suture begins at alSout the middle of the posterior border of the interpterygoid vacuity and trends pos tero la tera l ly , ending at the posteriormost edge of the base of the quadrate ramus. The exoccipital-parasphenoid suture, however, is not readily discernible in ventral view. Previous authors (Watson, 1962; Welles & Cosgriff, 1965) have established that the parasphenoid overlaps the exoccipital in this region. A moderately interdigitated suture between these two elements is visible in dorsal view. The contact arches anteromedially from the base of the quadrate ramus to the free edge of the parasphenoid.

The basal plate of the parasphenoid tapers in thickness posteriorly from a robust anterior edge to a thin, free posterior margin situated beneath and between the exoccipita! condyles. On the palatal surface, a raised mound of cancellous bone at the anteromedial edge appears to be the base of a keeled cultriform process. Remnants of the crista muscularis obliquely traverse the posterior border of the basal plate just anterior to the parasphenoid- exoccipital suture. The ridge is strongly developed laterally and gradually diminishes in height anteromedially. The m. rectus capitis presumably inserted on this ridge. The aforementioned raised areas along with the tapering nature of the parasphenoid combine

I

Vo J I

f l

t I

J ,t /

[ /;I ]

Ps

Pt

Fig. 3. Outline of a generalized parotosuchian skull showing the positions of palatal fragments UTGD95385 (includes portions of jugal, maxillary, ectopterygoid and pterygoid) and WSUPCI102 (includes portions of pterygoid, parasphenoid and exoccipital). Individual palatal fragments have been proportionately scaled.

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A L C H E R I N G A TASMANIAN CAPITOSAURID 29

to p roduce a cent ra l ly located, shal low el l ipt ical depress ion an t e romed ia l to the condyles .

Dorsa l ly , the t o p o g r a p h y o f the para - spheno id is more complex . A ra ther low but

b r o a d ridge sweeps pos t e romed ia l l y f rom the pos te r ior edge o f the conical recess, obl iquely subdividing the pa raspheno id into two basins: a larger , central basin which receives the media l extension o f the conica l recess and a

A B

P

Ju

Ec Mx s. j

E

~I.C P

~S

Eo

Fig. 4. ? Parotosuchus sp. ventral skull fragments. A, B, UTGD95385 in ventral and lateral views. C, D, WSUPC1102 in ventral and dorsal views. Bar scale equals 1 cm.

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30 J. W. COSGRIFF AND S. L. DEFAUW ALCHERINGA

much smaller, more lateral depression which presumably was occupied by the foot of the pro-otic (Watson, 1919). A small foramen for the internal carotid artery is located directly medial to the conical recess.

The pterygoid consists of a body, a palatine ramus and a quadrate ramus. The lateral edges of this bone comprise the medial border of the subtemporal fenestra. Ventrally, the contours of the pterygoid body are quite simple, consisting of: a planar, central region; a sharply downcurved anterior edge which forms part of the border of the interpterygoid vacuity; and, gently sloping lateral and posterior margins. In dorsal view, however, pterygoid topography increases in complexity. A pinnate flap of bone partially roofs the conical recess. The posterior border of this recess fo rms a r idge which ex tends posteromedially on to the parasphenoid, ab rup t ly t e rmina t ing 8 mm f rom the exocc ip i ta l -parasphenoid suture. Other authors (Bystrov & Efremov, 1940; Welles & Cosgriff, 1965) have termed the ridge in this area the crista parapterygoidea (parapterygoid crest). In all previously described material the ridge trends anteromedially. The Tasmanian fragment, however, displays a crest which extends posteromedially. The ascending ramus arises just lateral to the posterior border of the conical recess and continues out on to the quadrate ramus. This rather thin wall of bone is broken off near its base exposing a narrow (3-4 mm wide), slightly arcuate trough.

Of the indices established by Welles & Cosgriff (1965), only the Q:R ratio (which compares the length of the pterygoid behind the interpterygoid vacuity to the breadth across the pterygoids) of this palatal fragment is estimable. A calculated value of 54 ten ta t ive ly allies this specimen with Parotosuchus birdi (from the Wupatki Member of the Moenkopi Formation) which derives from a horizon younger than the Knocklofty Format ion. Cyclotosaurs of Norian age likewise exhibit high Q:R ratios (Welles & Cosgriff, 1965) ranging in value from 46 (C. ebrachensis) up to 60 (C. robustus).

The distal ends of both pterygoid rami are incomplete. Both bear traces of sculpturing on their ventral surfaces. The lateral edge of the

palatine ramus is ornamented with small tubercles and faint ridges and is, therefore, sharply set of f from the more medial surface which is smooth and slightly convex. The quadrate ramus carries a series of nested parabolic ridges preceded by a sizeable foramen which pierces its anterolateral edge. A short but deep groove extends postero- laterally from this foramen and presumably facilitates the directional transition of a nerve-vessel bundle from a dorsomedial to a ventrolateral course.

The exoccipital is a complex bone. In ventral view its extent is obscured by squamous overlap of the basal plate of the parasphenopid. Dorsally, its sutures with the pterygoid and parasphenoid may be traced. The condyle faces posteriorly, for the most part, with moderate ventral and medial components. The entire ovoid articular area consists of cancellous bone, indicative of a cartilaginous overlay. A stout flange arises from the dorsal surface of the exoccipital immediately above the condyle. It is broken off at the level where it bifurcates to form the postparietal and tabular processes. The two medial extensions from the postparietal process, the processus lamellosus and the processus basalis, are not evident on this fragment. A ridge of bone extending anteriorly from the parocciptal process forms the medial border of the fenestra ovalis. Bystrov & Efremov (1940) term this bony flange the processus subtympanicus.

Although WSUPCII02 reflects general capitosaurid construction in the configuration and arrangment of its elements, it remains problematical in a number of aspects. First, the Q:R ratio is significantly higher than the range established for Scythian capitosaurs by Welles & Cosgriff (1965). This reflects a long pterygoid body which is atypical for these early forms. Secondly, the lateral edge of the crista muscularis lies well behind the base of the quadrate ramus. Thirdly, the position of the sculptured patch on the quadrate ramus of the pterygoid is unusual. Howie (1970, p. 213, fig. 1) reported a textured area of bone on the anterior surface of the quadrate ramus of P. pronus and suggested that it represents 'a continuation on to the pterygoid of the articular surface of the screw-shaped quadrate condyle ' . In no known capitosaur, however,

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ALCHERINGA TASMANIAN CAPITOSAURID 31

does an extension of the quadrate overlap the ventral surface of the quadrate ramus as would have to be the case in WSUPC1102 if this region is interpreted as such. In addition, a foramen in this area has not been reported previously in capitosaurids. Lastly, the distance between the occipital condyles is quite broad in proportion to the skull length for capitosaurids and more closely resembles the t rematosaurid condition (Romer, 1947). Nevertheless, these anomalous features are of less significance for taxonomic assignment than the capitosaurid features of the fragment such as the strong crista muscularis and the well marked notch on the posterior edge between the exoccipital and the quadrate ramus of the pterygoid. Near coincidence of

the Q:R ratio of the Tasmanian specimen (estimated Q:R value is 54) with that of P. birdi (which possesses a Q:R index of 53) s u p p o r t s a t en t a t ive ass ignment of WSUPC1102 to the genus Parotosuchus.

Lower jaw fragments. Of the posterior lower jaw portions, UTGD95395 (Figs 5, 6A-D) is far more extensive than UTGD95677 and preserves all portions retained on the latter; it suffices, therefore, as the basis for description and discussion. Although some- what crushed and linguolabially compressed, it is complete from a point close to the tip of the retroarticular process to a level just behind the anterior edge of the adductor fossa. Major structures preserved include: the labial wall;

Ang

B

A D e n . i - . . . . : . , :

C

Sa

Fig. 5. Outline of a generalized parotosuchian lower jaw showing the positions of UTGD95384 (includes portions of dentary, angular, postsplenial, prearticular, intercoronoid and coronoid bones) and UTGD95395 (includes portions of dentary, angular, surangular, prearticular and articular bones). UTGD95384 has been illustrated here as a left lower jaw fragment. A, labial view. B, dorsal view. C, lingual view. Individual lower jaw fragments have been proportionately scaled.

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32 J. W. C O S G R I F F A N D S. L. D E F A U W A L C H E R I N G A

A D e n

). ra

B A n ~ lb. ad

). ra

C f. c

p. r~

m . l ib. ad ~fl

D

Sa A n g Pa

p. r~

D e n E F

| 4

A n g

Ang f . m . p

Fig. 6. ?Parotosuchus sp. lower jaw fragments. A, B, C, D, UTGD95395 in labial, dorsal, lingual and ventral views. E, F, UTGD95384 in labial and lingual views. Bar scale equals 1 cm.

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ALCHERINGA TASMANIAN CAPITOSAURID 33

the lingual wall; most of the adductor fossa; the glenoid facet (whose posterior portion is restored with plaster); and the slightly battered retroarticular process. UTGD95677 preserves only the badly damaged glenoid facet and small pieces of the labial and lingual walls adjacent to the facet.

P o r t i o n s of th ree bones, angular , surangular and dentary, comprise the labial wall. The angular-surangular suture curves posteroventrally across the walt to a point below the glenoid facet where it reached the ventral edge. This configuration is in contrast with some previously figured capitosaurid lower jaws. In other described species (Parotosuchus peabodyi Welles & Cosgriff, 1965, fig. 45; P. pronus Howie, 1970, fig. 9B; P. ?megarhinus Chernin, 1974, fig. 3; P. dirus Chernin, 1978, fig. 7) the suture remains on the labial wall back on to the retroarticular process. Coarse sculpture covers the entire angular and the lower part of the surangular. The upper part of the latter, the regions below the adductor fossa and the glenoid facet, are smooth surfaced as is the case in most other temnospondyls. The sculpture on the angular radiates from the ossification centre at the anteroventral corner of the fragment and consists of grooves separated by irregular, wavy ridges. The sculpture on the anterior part of the surangular is of the same type but that on the posterior part, beneath the glenoid facet a n d on the retroarticular process, consists of pits which vary in diameter and depth. One particularly deep, wide and fairly continuous groove begins on the angular near its oss i f ica t ion cen t re and t rends posterodorsally, at a low angle, towards the surangular where it fades out; this appears to be the poorly developed mandibular groove (sulcus mandibularis) of the lateral line system. Faint traces of the oral groove (sulcus oralis) are observed, however, no evidence of the accessory groove (sulcus accessorius) remains. In this, the present specimen contrasts with lower jaws of most other capitosaurids where these grooves are clearly impressed on the bone surface. Another feature to be noted on the surangular is the external n. chorda tympani foramen which lies just below the forward edge of the glenoid facet. The last bone contributing to the labial wall is the dentary. The only part of this bone

retained on the specimen is the thin, wedge- shaped extension (present in almost all temnospondyls) plated on to the surface of the surangular.

Three bones, angular, surangular and prearticular, comprise the lingual wall of UTGD95395. The borders of these are hard to distinguish from the many artificial cracks on the surface but their traces, certain in some places and inferred in others, are indicated on Fig. 5C. The suture separating the angular from the bones above has an undulating but generally posteroventral course terminating at the ventral edge below the level of the glenoid facet. The lingual exposure of the surangular is roughly triangular, lying below the articular facet, above the angular and behind the prearticular. Its suture with the latter is saw- toothed but generally vertical. The internal n. chorda tympani foramen lies near the centre of this suture. The dorsal edge of the prearticular forms the inner border of the adductor fossa. Behind the fossa, the prearticular is produced dorsally as the massive, pyramidal hamate process.

The adductor fossa, still largely infilled with matrix, makes up most of the dorsal aspect of UTGD95395. Its borders are formed by the thin edge of the prearticular lingually, the swollen edge of the surangular labially and the precondylar process of the articular poster ior ly . The swollen edge of the surangular carries a well marked groove down its length which corresponds to the same feature on Rhineceps nyasaensis indentified by Watson (1962, p. 238, fig. 8) as the insertion area for a labial muscle.

The glenoid facet is floored by the articular bone. As usual, it is divided into two moieties by a low, broad swell. The lingual moiety, measured anteroposteriorly, is more than twice the length of the labial moiety. This elongation of the inner half of the glenoid (a l though not necessar i ly to the aforementioned extent) is characteristic of capitosaurs (Watson, 1962; Welles & Cosgriff, 1965).

The retroar t icular process is largely complete although its dorsal and posterior surfaces have suffered some erosional damage. The sharply keeled ventral edge and the dorsal labial edge are intact but perhaps

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34 J .W. COSGRIFF AND S. L. DEFAUW ALCHERINGA

1-2 mm is missing from the dorsal lingual edge and the posterior edge. The adductor fossa onothe dorsal surface which housed the insertion of the m. depressor mandibulae has probably lost its floor to erosion but this is uncertain as matrix still covers the surface, removal of which would damage adjacent areas. The entire process is set very low on the jaw, well below the general level of the articular facet. In this respect, there is concurrence with the lower jaws of such capitosaurids as laarotosuchus sp. (Edinger, 1937, fig. 3), Wetlugasaurus magnus (Watson, 1962, fig. 12; synonymised with Parotosuchus sp. Welles & Cosgriff , 1965, p. 81), Parotosuchus dirus (Chernin, 1978, figs 7A, B and 8B, D) and Parotosuchus megarhinus (Chernin, 1978, fig. 8A, C). A difference from the above mentioned forms (wit.h the exception of P. megarhinus), however, concerns the lower edge of the process which, on the present specimen, is set at a low angle to the lower edge of the jaw in front of it and slopes posterodorsally (a feature also observed in P. megarhinus). In the remaining forms, the lower edge of the process is continuous with the lower edge in front of it. Certain other species of the family show a high set of the retroarticular process so that it is on approximately the same level as the articular facet. These include: Paracyclotosaurus davidi (Watson, 1958, fig. 6); Parotosuchus orenburgensis (Konzhukova, 1965, fig. 4); Parotosuchus peabodyi (Welles & Cosgriff, 1965, fig. 45) and Parotosuchus pronus (Howie, 1970, fig. 9). Watson (1962, p. 251) notes that a fragment from a lower jaw of the type species o f Wetlugasaurus, W. angustifrons, shows a straight lower edge (and, therefore, a low set retroarticular process) and that this character may serve as a distinction between Wetlugasaurus and Parotosuchus. The Wetlugasaurus- Parotosuchus t a x o n o m i c p r o b l e m is considered in the following section.

UTGD95384 (Figs 5, 6E, F), a central section from a right ramus considerably smaller than the ramus represented by UTGD95395, is the only other lower jaw fragment in the present collection which pertains to the Capitosauridae. It is also linguolabially crushed and compressed and is prepared on both lingual and labial surfaces.

Broken tooth bases of the marginal tooth row line the dorsal edge of the labial surface. A large, oval posterior Meckelian foramen occupies most of the lingual surface, indicating that the fragment represents a jaw portion just anterior to the forward edge of the adductor fossa.

Portions of bones preserved on the labial surface include a smooth-surfaced extent of the dentary on the dorsal half and a sculptured extent of the angular on the ventral half. The angular sculpture consists of regular and alternating ridges and grooves which trend anterodorsally.

A large number of surface cracks appears on the lingual surface and these make impossible the certain determination of sutures dividing bones. By reference to this part of the jaw in other capitosaurids, it can be seen that portions of the postsplenial, angular, prearticular, dentary, intercoronoid and coronoid bones are all present. The posterior Meckelian foramen appears to have an intact dorsal margin but the anterior, ventral and posterior margins have all had some bone broken away from them.

All three lower jaw pieces are capitosaurid through combinations of characters rather than distinct derived features. Such characters of the posterior jaw fragment UTGD95395 (following principally the criteria of Watson, 1962, p. 250-254) include: the construction of the glenoid facet with its high precondylar and pos tcondyla r processes, the an te r ior ly extended lingual moiety of the glenoid; the well developed retroarticular process (as compared to rhinesuchids); the massive hamate process; and the character of the sculpture on the labial exposures of the angular and surangular bones. The low set of the retroarticular process allies this fragment with certain species of Parotosuchus. UTGD95677 , as ind ica ted above , is indeterminate by itself but matches corresponding portions of UTGD95395. UTGD95384 is tentatively identified as capitosaurid through the character of sculpture on the angular bone and through the placement, relative size and shape of the posterior Meckelian foramen.

Summary. All fragments here considered are capi tosaur id th rough combina t ions o f

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ALCHERINGA TASMANIAN CAP1TOSAURID 35

features although the posterior palate piece, WSUPCI102, is somewhat equivocal, showing several anomalous features. The fragments from the tabular region (UTGD85745, 85746, 95388 and 95699) and the posterior lower jaw fragments (UTGD95395 and 95677) all carry features i n common with described species of Parotosuchus and, thus, are assigned to this genus with a fair degree of certainty. The remaining fragments, the snout portion (UTGD95750), the palate pieces (UTGD95383 and WSUPC1102) and the central lower jaw piece (UTGD95384), seem definitive on the family level and are tentatively included in the genus Parotosuchus through locality and/or stratigraphic association.

Taxonomic problems The last comprehensive reviews of the Capitosauroidea and Capitosauridae, those of Welles & Cosgriff (1965) and Otschev (1966), are very divergent regarding genera and species considered taxonomically valid and regarding the evolutionary relationships among these as expressed in the provided classifications. Further, they are now of limited usefulness, even as compendia of previously described material~ as many new taxa have been added to both the superfamily and the family in recent years. Chernin & Cosgriff (1975) provided an addendum to these older reviews, listing new genera and. species reported up to that year and included a synopsis of differing views on phyletic relationships. Eschewing any attempt to resolve the complex taxonomic issues, they limited their consideration to a status report. As they noted: ' . . . alterations and additions have greatly added to the knowledge of the morphology, diversity and geographic distribution of the group and have raised numerous and provocative questions regarding its evolutionary radiation. As a result of this expansion, however, capitosauroid taxonomy is currently in a confused and unreconciled state'. A further update on taxonomic contents was given by Carroll &Winer (1977) in their classification of the Amphibia. They list all generally recognized capitosauroid genera and species

(together with geographic and stratigraphic sources) which were reported up to that year.

Since 1977, the following genera and species have been added: Parotosuchus dirus Chernin 1978, from the Early Triassic Cynognathus Zone of South Africa; Benthosphenus lozovskii Shishkin & Lozovskiy 1979, from the Early Triassic of southern Primor'e, U.S.S.R.; Parotosuchus rewanensis Warren 1980, and Parotosuchus gunganj Warren 1980, from the Early Triassic Arcadia Formation of Queensland; Parotosuchus sp. (Warren, 1980) from the Early Triassic Blina Shale of Western Australia; Wetlugasaurus samarensis Sennikov 1981, from the Vetluga Series of European U.S.S.R.; Cyclotosaurus cf. posthumus Fraas 1913, (Ingavat & Janvier, 1981) from the Late Triassic Huai Hin Lat Formation of Thailand; Trematotegmen otschevi Getmanov 1982, from the Early Triassic of Obshchego Syrta, U.S.S.R.; Odenwaldia heidelbergensis Morales & Kamphausen 1984 from the Middle Buntsandstein of Germany; and Stenotosaurus gracilis Kamphausen 1983, from the Lower Rottone, Upper Bunter of southern Germany. A recent alteration is the new combination, Eocyclotosaurus lehmani, proposed by Kamphausen & Morales (1981) for Stenotosaurus lehmani Heyler 1969, from the Early to Middle Triassic Upper Bunter Formation of France.

In addition to the diverse and contrasting taxonomic lists and phylogenies discussed in the literature review by Chernin & Cosgriff (1975), four more interpretations of relationships within the Capitosauroidea have appeared in recent years. Heyler (1976) elaborates on the sharp separation of Steno- .tosaurus from other capitosauroids and continues to segregate this genus in its own family, Stenotosauridae Heyler 1969. He concludes that the families Stenotosauridae and Cyclotosauridae derive from separate sources within the Early Triassic parotosuchians. Shishkin (1980) re-examined and revised the composition of the Capitosauroidea and Trematosauroidea. The families Rhinesuchidae, Uranocentro- dontidae Luzocephalidae fam. nov., Lydekkerinidae, Sclerothoracidae, Capito- sauridae, Stenotosauridae, and Mastodon- sauridae are placed in the former taxon,

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36 J. W. COSGRIFF AND S. L. DEFAUW ALCHERINGA

whereas the families Ben thosuch idae , Heylerosauridae fam. nov. and Tremato- sauridae are included in the latter. Here the form Stenotosaurus lehmani Heyler 1969 is regarded as a separate genus, Heylerosaurus gen. nov. , p laced in its own family Heylerosauridae fam. nov., and interpreted as a descendent of the Benthosuchidae. The type species Stenotosaurus semiclausus (Swinton 1927), however, is grouped together with Cyclotosaurus leptognathus Paton 1974 (in Shishkin's opinion, this form should be placed in the genus Stenotosaurus) , Wellesaurus ( 'Parotosuchus') peabodyi (Welles & Cosgriff 1965), and Eocycloto- saurus woschmidti Ortlam 1970 in the family Stenotosauridae. Cosgriff (1984) synonymized the family Luzocephalidae with the Lydekker- inidae. Kamphausen & Morales (1981), in a cladogram, divide the Capitosauridae into two groups, one containing Wetlugasaurus and Eocyclotosaurus and the other Parotosuchus, Stenotosaurus and Cyclotosaurus. Ingavat & Janvier (1981) summarize their conclusions in a cladogram which is similar, in part, to the previous one in that it clusters Parotosuchus, Stenotosaurus and Cyctotosaurus. However, it departs radically from other phylogenetic and cladistic treatments as it narrows the family Capitosauridae sensu stricto to include only the stenotosaurs and cyclotosaurs plus one parotosuchian, P. nasutus; it excludes from this taxon such species as Wetlugasaurus kzilsajensis, Parotosuchus rewanensis and Parotosuchus helgolandicus. Also, it differs from the cladogram of Kamphausen & Morales in that Eocyclotosaurus is regarded as a synonym of Stenotosaurus.

Thus, resolution of problems leading to a proper classification of the Capitosauroidea and Capitosauridae which reflects actual evolutionary relationships, has made no progress in recent years. Indeed, through the many divergent interpretations, uncertainty has greatly increased. But, on reflection, this has been predictable considering two factors involved in analysis of these groups. First, many species within genera and many genera within families are distinguished from each other by very few significant morphologic differences. And second, the groups have been extensively analysed by investigators scattered over the world, most of whom have lacked

access to major collections housed elsewhere. Regarding the first factor, difficulty in identifying reliable synapomorphic characters, there is strong suggestion that mosaic evolution has pervaded the superfamily and that parallel character changes have occurred frequently. Regarding the second, the groups have attracted much attention as material representing them is very common (for Triassic vertebrates) in continental deposits around the world. Throughout most of the Early Triassic, the groups are nearly world- wide and in the Late Triassic the distribution, if not as extensive, is quite notable. Hence, capitosauroids have been perceived as conta in ing cons ide rab le po ten t ia l for b io s t r a t i g r aph ic purposes and for evolut ionary studies. Neither o f these potentials can be realized, however, until an authoritative and thorough review of the capitosauroid families is accomplished and receives the acceptance of most investigators.

Although such a review is not undertaken in the present paper, the tentative assignment of the new material from the Knocklofty Formation to a particular capitosaurid genus, Parotosuchus, needs justification. For this purpose, only those genera with open otic notches from the 'AI ' horizon are relevant: Kestrosaurus Haughton 1925; Parotosuchus Otschev and Shishkin 1968; and Wetluga- saurus Riabinin 1930. Welles & Cosgriff (1965) recognized the first two of these but sy n o n y m ized Wetlugasaurus with Parotosuchus. It is apparent that the new material does not pertain to Kestrosaurus and, thus, this form can be removed from con- sideration first before focussing on the more complex issue, the Parotosuchus-Wetluga- saurus problem.

Chernin (1978) has redescribed and re- assessed the sole species of Kestrosaitrus, K. dreyeri Haughton 1925, which derives from the Lystrosaurus Zone of South Africa. As she af f i rms , this i s - a very aber ran t capitosaurid and the generic distinction should be maintained. It contrasts with species of Parotosuchus, including the present material, through a combination of character states which includes inter alia: a very narrow snout; short, triangular tabular horns which project at nearly right angles to the midline; and

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ALCHERINGA TASMANIAN CAPITOSAURID 37

proportionately very short parasphenoid- pterygoid sutures on the palate surface.

Wetlugasaurus is a far more extensive genus in terms of included species and geographic distribution. Members of this genus have been r epo r t ed f rom E u r o p e a n U . S . S . R . , Greenland, Madagascar and South Africa. The type species, W. angustifrons Riabinin 1930, occurs in the Vetluga Series of the Soviet Union west of the Urals and its cranium has recently been redescribed by Sennikov (1981). A number of additional species from the Vetluga Series has also been described. Sennikov (1981) provides the most current opinion on the taxonomic status of some of these according to which W. kzilsajensis Otschev 1972 is a distinct species, but W. volgensis Hartmann-Weinberg & Kuzmin 1936, and W. kalajevi Kuzmin 1937, and possibly W. cornutus Efremov 1940, are junior synonyms of W. angustifrons. In that same paper, an additional species, W. samarensis Sennikov 1981, is described. The Greenland species is W. groenlandicus Save- Soderbergh 1935 and the Madagascar species is W. milloti Lehman 1961. W. magnus Watson 1962, from the Cynognathus Zone of South Africa, is the only reported occurence of the genus from a level above the 'AI ' horizon. Watson (1919) originally described the single incomplete cranium of this form as Capitosaur{ts sp., but later (1962) renamed it.

Sennikov (1981) states that Sassenisaurus spitzbergensis is probably a wetlugasaur, being indistinguishable from W. kzilsajensis. This form, placed in the Bukobajidae by Otschev (1966) but regarded as a nomen vanum by Welles & Cosgriff (1965), is known only from a single snout fragment.

To date , the onIy ' A I ' ho r i zon capitosaurids to be placed in Parotosuchus by their initial describers are from Australian region. These include the form described here and those described by Warren (1980), namely P. gunganj and P. rewanensis from the Arcadia Formation of Queensland and P. sp. from the Blina Shale of Western Australia. Warren (1980) suggested that both P. gunganj and P. rewanensis were close to Wetlugasaurus.

Romer (1947), fol lowing principally Riabinin (1930), used as the prime character

to distinguish Wetlugasaurus (i.e. W. angustifrons) f rom Parotosuchus the exclusion of the frontal borne from the medial margin of the orbit through a sutural contact of the prefrontal bone with the postfrontal bone. Subsidiary differences cited by him include the larger, more posterior external naris and the lack of pronounced lateral expansion of the postorbital bone. Regarding the prime character, minor differences in sutural relationships among the bones of the skull roof occur commonly between species of the same genus and between individuals of the same species in labyrinthodonts. Thus, the exclusion of the frontal bone from the orbit is probably of little taxonomic significance. The fact that it is excluded from the orbit on one side of the skull in Parotosuchus wadei (Cosgriff, 1972) but not on the the other makes it a particularly suspect character. The other two characters are quite variable among the species of both Wetlugasaurus and Parotosuchus (see illustrations in Welles & Cosgriff, 1965) and are, thereby, also weightless as generic features.

Watson (1962) expanded the list of supposed differences between the genera by noting characters shared by W. angustifrons and W. magnus but not by P. nasutus, the type species of Parotosuchus. Three of the more important of these, the interorbital breadth (stated to be proportionately less in Wetlugasaurus), the posterior border of the skull roof (implied to be more deeply concave in Wetlugasaurus) and the length of the interpterygoid vacuity (stated to be relatively shorter in Wetlugasaurus) were shown by Welles & Cosgriff (1965, figs 5, 11 and p. 10, 49 and 86 for W. angustifrons only) to fall within the ranges encompassed by the species of Parotosuchus. Two other characters in this list seemed to be validated by the analyses of Welles & Cosgriff (1965, figs 4, 12), namely the height of the occiput (greater in Wetlugasaurus) and the length of the parasphenoid-pterygoid suture (shorter in Wetlugasaurus); in bo th cases W. angustifrons lies outside the range for Parotosuchus species. However , these features are of uncertain value. Regarding the first, most capitosaurid skulls, as found, are dorsoventrally compressed to some degree from their original states; the skull of the type

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38 J .W. COSGRIFF AND S. L. DEFAUW ALCHERINGA

specimen of IV. angustifrons may be a relatively undistorted example. Regarding the second, ils taxonomic usefulness is weakened by the fact that in one parotosuchian species, P. helgolandicus, the relative length of the suture is only a fractional amount greater. Three further distinctions cited by Watson (1962) as qualitative character states seem trivial, perhaps of specific rather than generic significance. They are: the presence in both Wetlugasaurus species of a straight (rather than curved) ventral edge of the lower jaw; the sculptured (rather than smooth) para- sphenoid corpus; and an unsculptured area of the skull roof along the anterior edge of the otic notch.

Otschev (1966), in his review o f cap i tosaur id sys temat ics , l is ted 26 morpho log ic fea tures tha i serve to differentiate the genus Wetlugasaurus from the genus Parotosuchus. Collectively, over half of these were expounded in the aforementioned reviews of Romer (1947) and Watson (1962) as well as Riabinin's (1930) descr ip t ion o f the type species W. angustifrons. Many of the remaining characters are either equivocal (i.e. Otschev admits that primitive parotosuchians such as P. panteleevi cannot be distinguished from wetlugasaurs based on these) or plesiomorphic for the Capitosauridae. Those characters most frequently noted as distinctive by Otschev include: 1. exclusion of the frontal bones from the orbit margins in Wetlugasaurus; 2. a small field of shagreen may be preserved on the parasphenoid corpus in Wetlugasaurus; 3. the tooth row posterior to the anterior palatal vacuity is arched or angled in Wetlugasaurus (straight in Parotosuchus); 4. the processus cultriformis reaches the level of the posterior edge of the choana in parotosuchians whereas in Wetlugasaurus this anterior extension of the parasphenoid is covered by the vomers and therefore does not reach that far forward; 5. a well developed processus basalis of the epipterygoid is lacking in Wetlugasaurus but present in Parotosuchus; and 6. the descending b ranch o f the t abu la r in Wetlugasaurus is somewhat sho r t e r . Characters of the lower jaw noted as distinctive by Otschev (1966, 1969, and 1974) include: 1. the torus arcuatus of the surangular is re la t ively n a r r o w in

Wetlugasaurus whereas this ledge of bone is broader medially in Parotosuchus; 2. the medial branch of the surangular (beneath the jaw articulation) is more weakly developed in Wetlugasaurus than in Parotosuchus. All of these are plesiomorphies shared with either benthosuchids or rhinesuchids or are common to all three families.

Although W. magnus does seem to be a rather primitive capitosaurid on certain of the above characters e.g. the deep occiput and the short parasphenoid-pterygoid suture, these are, at best, plesiomorphic characters for the Capitosauridae. They do not, by themselves, provide evidence for placing this form in the same genus with W. angustifrons. Sennikov (1981) agrees that this form is not a wetlugasaur. Indeed, W. magnus lacks the character state which is generally regarded as central to Wetlugasaurus, namely the exclusion of the frontal bone from the medial orbit margin. Otschev (1966) erected a new genus, Watsonisuchus, for this form but Welles & Cosgriff (1965) maintained it as Parotosuchus sp. The latter designation is recommended here. As expressed below, a lumping rather than a splitting approach to capitosaurid taxonomy is more objective and more practical in the present understanding of the evolution of this group.

Wetlugasaurus groenlandicus is known only from two partial skulls from the Wordy Creek Formation of Greenland; both specimens preserve only the back part of the skull. The prime character state, exclusion of the frontal bone from the medial margin of the orbit, is present but little else of a specifically Wetluga- saurus nature is to be observed. Otschev (1966) includes this form in his classification as HI. groenlandicus and Sennikov (1981) concurs that it is probably a wetlugasaur. Welles & Cosgriff (1965), however, regarded the taxon as a nomen vanum, stating that: ' . . . the material is not adequate for specific or perhaps even generic determination'. On review, the latter course seems too extreme as the general proportions of parts preserved, the relative sizes and shapes of the orbit, otic notch and tabular horn, and the suture pattern strongly suggest a parotosuchian. It should be designated Parotosuchus sp.

The last referred species of the genus, from the Middle Sakamena Group of Madagascar,

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ALCHERINGA TASMANIAN CAPITOSAURID 39

was designated by Lehman (1961) as W. milloti in one place and as W. sp. in another. It encompasses a large hypodigm which includes an extensively preserved skull. This form shares the exclusion of the frontal bone from the medial margin of the orbit with W. angustifrons but, on the other hand, exhibits a number of skull features enumerated by Welles & Cosgriff (1965) which seem to place it outside the bounds of the Capitosauridae. Welles & Cosgriff (1965)concluded: 'There seems less reason to ally this species with the cyclotosaurs (i.e. capitosaurs) than with the rhinesuchids . . .' Sennikov (1981) parallels this doubt, stating that it is probably not a wetlugasaur. The present consideration also leaves the issue unresolved as it does not bear directly on the status of either Wetlugasaurus or Parotosuchus.

With the exclusion of W. magnus, W. groenlandicus and W. milloti, and the designation of the first two of these Parotosuchus sp. and the last as incertae sedis, the remaining conten ts of the genus Wetlugasaurus include W. angustifrons, W. kzilsajensis, and W. samarensis from the European U.S.S.R. It is here proposed that all of these be transferred to Parotosuchus. This reiterates the position of Welles & Cosgriff (1965). The present authors feel that there has been a subjective element in the Wetlugasaurus-Parotosuchus dichotomy, namely that it has been based more on s t r a t i g raphy than on m o r p h o l o g y ; capitosaurids from the 'AI ' horizon have most often been placed in Wetlugasaurus whereas those from the 'A2' horizon, with the exception of W. magnus, have been placed in Parotosuchus.

This taxonomic course does not reflect a belief that Parotosuchus will remain an undivided genus or that it is a taxonomically simple group. Indeed, it has always been a very recondite one to deal with. It is, at first glance, a well-defined group, set off from related forms on reliable characters. On closer inspection, however, it turns out to be an extensive complex which includes a large number of species diagnosed from a suite of varying characters, some of which may be taxonomically significant and some not. We feel that future considerations of the group

will be more objectively based if they embark f rom a ' l u m p e d ' r a the r than ' sp l i t ' arrangement. The number of species involved, the geographic and stratigraphic ranges encompassed by these and the number of morphologic characters with varying states makes the parotosuchians a fossil group with unusual potential for documenting small scale evolution through time and across area. It is a group amenable to phenetic and cladistic analysis. A comprehensive review may retain the single genus, may re-establish the Wetlugasaurus-Parotosuchus split, or may create entirely new divisions.

Acknowledgements We thank Dr M. R. Banks of the Department of Geology, University of Tasmania for the loan of the specimens. Dr A. A. Warren and Dr M. Morales reviewed the manuscript; their comments and suggestions enhanced the quality as well as clarity of this work and their input is greatly appreciated. Mr P. J. English of the Department of Radiation Oncology assisted in the preparation and layout of the photographs, and Ms P. Gavric of the Department of Biological Sciences typed portions of the manuscript. Preliminary research at the University of Tasmania, during 1975, was supported by the Australian Research Grants Committee. Subsequent research, at Wayne State University, was supported by the National Science Foundation (DPP 80-19996 to J.W.C.), National Institute of Health Grant 7051 (to J.W.C. and S.L.D.), and the Thomas C. Rumble University Fellowship (to S.L.D.).

REFERENCES BANKS, M. R., & NAQVl, I. H., 1967. Some formations

close to the Permo-Triassic boundary in Tasmania. Papers and Proceedings o f the Royal Society o f Tasmania 101, 17-30.

BANKS, M. R., COSGRIFF, J. W., & KEMP, N. R., 1978. A Tasmanian Triassic Stream Community. Australian Natural History 19, 150-157.

BROILI, F., & SCHRODER, H. C., 1937. Beobachtungen an Wirbeltieren tier Karrooformation. XXVIL 15bet einen Capitosauriden aus der Cynognathus Zone. Sitzungsberichte der bayerischen Akademie der, Wissenschafien 1937, 9-117 (German).

BROOM, R., 1908. On a new labyrinthodont , Rhinesuchus whaitsi, from the Permian beds of South Africa. Annals o f the South African Museum 4, 373-376.

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40 J . W . C O S G R I F F AND S. L. D E F A U W A L C H E R I N G A

BYSTROV, A. P., & EFREMOV, YU. A., 1940. Benthosuchus sushkini Efr. - - labirintodont iz Eotriasa reki Sharzhengi. [Benthosuchus sushkini - - A Iabyrinthodont from the Eotriassic of Sharzhenga River] Trudy Paleontologicheskogo lnstituta 10(1), 1-152 (Russian).

CAMP, C. L., & BANKS, M. R., 1978. A proterosuchian reptile from the Early Triassic of Tasmania. Alcheringa 2, 143-158.

CARROt L, R. L., & WINER, L., 1977. Appendix to accompany Chapter 13. Patterns of amphibian evolution: an extended example of incompleteness of the fossil record. Classification of amphibians and list of genera and species known as fossils, 1-13. In Patterns of Evolution, A. Hallam, ed., Elsevier, Amsterdam, 405-437.

CHERNIN, S., 1974. Capitosaurid amphibians from the Upper Luangwa Valley, Zambia. Palaeontologia Africana 17, 33-55.

CHERNIN, S., 1978. Three capitosaurs from the Triassic of South Africa: Parotosuchus africanus (Broom, 1909), Kestrosaurus dreyeri Haughton, 1925, and Parotosuchus dirus sp. nov. Palaeontologia Africana 21, 79-100.

CHERNIN, S., & COSGRIFF, J. W., 1975. Further consideration of the capitosaurids from the Upper Luangwa Valley, Zambia. Palaeontologia Africana 18, 143-148.

CHERNIN, S., 8~ CRUICKSHANK, A. R. I., 1978. The myth of the bottom-dwelling capitosaur amphibians. South African Journal of Science 74, 111-112.

COSGRIFF, J. W., 1972. Parotosuchus wadei, a new capitosaurid from New South Wales. Journal of Paleontology 46(4), 545-555.

COSGRIFF, J. W., 1974. Lower Triassic Temnospondyli of Tasmania. Special Papers of the Geological Society of America 149, 134p.

COSGRIFF, J. W. 1984. The temnospondyl labyrinthodonts of the earliest Triassic. Journal o f Vertebrate Paleontology 14(1), 30-46.

COSGRIFF, J. W., 8¢ HAMMER, W. R., 1983. The labyrinthodont amphibians of the earliest Triassic from Antarctica, Tasmania and South Africa. In Antarctic Earth Science, R. L. Oliver, P. R. James and J. B. Jago, eds, Australian Academy of Science, Canberra, 590-592.

DZIEWA, T. J., 1980. Early Triassic osteichthyans from the Knocklofly Formation of Tasmania. Papers and Proceedings o f the Royal Society of Tasmania 114, 145-160.

EDINGER. T., 1937. Capitosaurus -- Gaumen und Unterkiefer aus Sfiddeutschen Haupt- Bundsandstein. Senckenbergiana 19, 181-192 (German).

ErREMOV, Yu. A., 1940. Predvaritel'hoe opisanie novykh form permskoy i triasovoy fauny nazemnykh pozvonochnykh SSSR. [Preliminary description of the new Permian and Triassic Tetrapoda from U.S.S.R.] Trudy Paleontologicheskogo Instituta 10(2), 1-140 (Russian).

FRAAS, E., 1913. Neue Labyrinthodonten aus der Schw/ibischen Trias. Palaeontographica 60, 275-294 (German).

GETMANOV, S. N., 1982. Labirintodont iz nizhnego triasa Obshchego Syrta. [A labyrinthodont from the Lower Triassic of Obshchego Syrta] Paleontologicheskiy Zhurnal 1982(2), 103-108 (Russian).

HARTMANN WEINBERG, A., & KUZMIN, T. M., 1936. Untertriadische Stegocephalen der Oka-Zna Antiklinale. II. Capitosaurus volgensis. Problemy Paleontologii 1, 35-61 (German).

HAUGHTON, S. H., 1925. Investigations on South African Fossil Reptiles and Amphibia (Part 13). Descriptive catalogue of the Amphibia of the Karroo System. Annals o f the South African Museum 22, 227-261.

HEVLER, D., 1969. Un noveau St~gocephale du Trias inf6rieur des Vosges, Stenotosaurus lehmani. Annales de la Pal6ontologie des Vert6br6s 55, 73-85 (French).

HEYLER, D., 1976. Faune du Buntsandstein. VI. Sur Stenotosaurus lehmani, St6gocephale des Vosges, d' aprbs un crane de la collection Grauvogel-Gall. Annales de la Paldontologie des Vertdbrds 62, 127-158 (French).

HowIE, A. A., 1970. A new capitosaurid labyrinthodont from East Africa. Palaeontology •3(2), 210-253.

INGAVAT, R., & JANVIER, P., 1981. Cyclotosaurus cf. posthumus Fraas (Capitosauridae, Stereospondyli) from the Huai Hin Lat Formation (Upper Triassic), Northeastern Thailand, with a note on capitosaurid biogeography. GOobios 14(6), 711-725 (French).

JAEKEL, 0 . , 1922. Neues fiber Hemispondyla. Paldontologische Zeitschrift 5, 1-25 (German).

JAEKEL, 0. • PHILIPPI, E., 1903. Amphibien der Trias. Lethaea geognostica 2(1), 13-14 (German).

KALANDADZE, N. N., et al., 1968. Katalog permiskikh i triassovykh tetrapod SSSR. rCatalogue of Permian and Triassic Tetrapods )f the U.S.S.R.] In Verkhnepaleozoyskie i mez ~zoyskie zemnovoclnye ipresmykayushchiesya SSSR. [Upper Paleozoic and Mesozoic amphibians and reptiles of the U.S.S.R.] Moscow, 72-91 (Russian).

KAMPHAUSEN, D., 1983. Stenotosaurus gracilis, ein neuer Capitosauride (Stegocephalia) aus den Unteren Rottonen Oberfrankens. Neues Jahrbuch fiir Geologie und Paliiontologie, Monatshefte 1983(2), 119-128 (German).

KAMPHAUSEN, D., ~,~ MORAl ES, M., 1981. Eocyclotosaurus lehmani, a new combination for Stenotosaurus lehmani Heyler, 1969 (Amphibia). Neues Jahrbuch fiir Geologie und Palgiontologie, Monatshefte 1981( 11 ), 651-656.

KIPARISOVA, L. D., & Popov, Yu. N., 1956. Raschlenenie nizhnego otdela trisovoy sistemy na yarusy. [Subdivision of the lower series of the Triassic system into stages] Doklady Akademii Nauk SSSR 109(4), 113-116 (Russian).

KIPARISOVA, L. D., & PoPov, Yv. N., 1964. Proekt raschleneniya nizhnego otdela triasa na yarusy. - - Doklady sovetskikh geo!ogov na XXII sessii mezhdunarodnogo geologicheskogo kongresa., Problema 16A. M. [The project of subdivision of the Lower Triassic into stages; International Geological Congress, XXII Session, Reports Soviet Geologists, Problem 16A], 91-99 (Russian).

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A L C H E R I N G A T A S M A N I A N C A P I T O S A U R I D 41

K1TCHING, J. W., 1978. The stratigraphic distribution and occurrence of South African fossil Amphibia in the Beaufort Beds. Palaeontologia Africana 21, 101-112.

KONZHUKOVA, E. D., 1965. Novyy parotozavr iz triasa Priural'ya. [A new Parotosaurus from the Triassic of Cisuralia] Paleontologicheskiy Zhurnal 1965(1), 97-104 (Russian).

KUZMIN, F. M., 1937. Untertriadische Stegocephalen der Oka-Zna Antiklinale. 111. Volgasaurus kalajevi gen. et sp. nov. Problemy Paleontologii 2-3, 621-648 (German).

LEHMAN, J. P., 1961. Les St6gocephales du Trias de Madagascar. Annales de la Paldontologie des VertdbrSs 47, 109-154.

MORALES, M., & KAMPHAUSEN, D., 1984. Odenwaldia heidelbergensis, a new benthosuchid stegoephalian from the Middle Buntsandstein of the Odenwald, Germany. Neues Jahrbuch fiir Geologie und Paliiontologie, Monatshefte 1984(11), 673-683.

ORTLAM, D., 1970. Eocyclotosaurus woschmidti n.g. n.sp. - - ein neuer Capitosauridae aus dem Oberen Bundsandstein des n6rdlichen Schwarzwaldes. Neues Jahrbuch fiir Geologie und Pal6ontologie, Monatshefte 1970(9), 568-580 (German).

OTSCHEV [OCHEV], V. G., 1966. Sistematika ifilogeniya kapitozavroidnykh labirintodontov. [Systematics and phylogeny of capitosaurid labyrinthodonts] Saratov State University Press, Saratov, 184p. (Russian).

OTSCHEV, V. G., 1969. O nekotorykh voprosakh taksonomii i filogenii po povodu raboty S. Vellesa and D. Kosgriffa - - Reviziya labirintodontov sem. Capitosauridae. [On some questions of taxonomy and phylogeny in connection with the work by S. Welles and J. Cosgriff 'A revision of the labyrinthodont family Capitosauridae'] Voprosi geolgii yuzhnogo Urala i Po volzh "ya 5(1 ) [Questions of the geology of the southern Urals and the region along the Volga], 61-79 (Russian).

OTSCHEV, V.G., 1972. Kapitozavroidnye labirintodonty Yugo- Vostoka europeyskoy chasti SSSR. [Capitosaurid labyrinthodonts from the southeastern European part of the U.S.S.R.[ Saratov State University Press, Saratov, 269p. (Russian).

OTSC'HEV, V. G., 1974. K morfologii nizhney chelyusti nekotorikh triasovikh labirintodontov. [Towards a morphology of the lower jaw of some Triassic labyrinthodonts] Voprosi geologff yuzhnogo Urala i Povolzh'ya 9(1) ]Questions of the geology of the southern Urals and the region along the Volga], 73-87 (Russian).

PATON, R.L., 1974. Capitosauroid labyrinthodonts from the Trias of England. Palaeontology 17(2), 253-289.

RIABININ [RYABININ], A. N., 1930. Wetlugasaurus angustifrons nov. gen., nov. sp. iz nizhnego triasa Vetluzhskogo kraya. [A labyrinthodont stegocephalian Wetlugasaurus angustifrons nov. gen., nov. sp. from the Lower Triassic of Vetluga- land in northern Russia] Ezhegodnik Russkogo paleontologicheskogo Obshchestva 8, 49-76 (Russian).

ROMER, A. S., 1947. Review of the Labyrinthodontia. Bulletin o f the Museum o f Comparative Zoology, Harvard 99, 3-352.

ROMER, A. S., 1975. Intercontinental correlations of Triassic Gondwana vertebrate faunas. In Gondwana Geology, papers presented at the Third Gondwana Symposium, 1973. K. S. W. Campbell, ed., Australian National University Press, Canberra, 469-473.

SAVE-SODERBERGH, G., 1935. On the dermal bones of the head in labyrinthodont stegocephalians and primitive Reptilia with special reference to Eotriassic stegocephalians from East Greenland. Meddelelser om GreJnland 98(3), 1-211.

SCHRODER, H. C., 1913. Ein Stegocephalen-Sch~idel von Helgoland. Jahrbuch der preussischen geologischen Landesanstalt und Bergakademie 33(2), 232-264 (German).

SENNIKOV, A. G., 1981. Novyy vetlugazavr iz basseyna reki Samary. [A new wetlugasaur from the Samara River basin] Paleontologicheskiy Zhurna11981(2), 143-148.

SHISHKIN, M. A., 1980. The Luzocephalidae, a new Triassic labyrinthodont family. Paleontological Journal 14(1), 88-101.

SHISHKIN, M. S., & LOZOVSKIV, V. R., 1979. Labirintodont iz triasa Yuzhnogo Primor'ya. [A labyrinthodont from the Triassic of southern Primor'ye] Doklady A k ademii Nauk SSSR 246(1), 201-205 (Russian).

SPATH, L. F. 1935. Additions to the Eo-Triassic invertebrate fauna of East Greenland. Meddelelser om GreJnland 98(2), 1-115.

SWINTON, W. E., 1927. A new species of Capitosaurus from the Trias of the Black Forest. Annals and Magazine o f Natural History 9(20), 178-186.

TOZER, E. T., 1967. A standard for Triassic time. Bulletin o f the Geological Survey o f Canada 156, 1-103.

VAN HOEPEN, E. C. N., 1911. Korte, voorlopige beschrijving van te Senekal gevonden Stegocephalen. Annals o f the Transvaal Museum 3, 102-106 (Afrikaans).

WARREN, A. A., 1980. Parotosuchus from the Early Triassic of Queensland and Western Australia. Alcheringa 4, 25-36.

WATSON, D. M. S., 1919. The structure, evolution and origin of the Amphibia. The 'orders' Rachitomi and S~ereospondyli. Philosophical Transactions o f the Royal Society B209, 1-73.

WATSON, D. M. S., 1958. A new labyrinthodont (Paracyclotosaurus) from the Upper Trias of New South Wales. Bulletin o f the British Museum (Natural History) 3(7), 235-263.

WATSON, D. M. S., 1962. The evolution of the labyrinthodonts. Philosophical Transactions o f the Royal Society 245B, 219-265.

WEt.LES, S. P., & COSGR~FF, J. W., 1965. A revision of the labyrinthodont family Capitosauridae. University o f California Publications in Geological Science 54, 148p.

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