DOLICHURANUS PRIMAEVUS (THERAPSIDA:

ANOMODONTIA) FROM THE MIDDLE TRIASSIC OF

NAMIBIA AND ITS PHYLOGENETIC RELATIONSHIPS

by ROSS DAMIANI* , CECILIO VASCONCELOS� , ALAIN RENAUT� ,

JOHN HANCOX� and ADAM YATES�*Staatliches Museum fur Naturkunde Stuttgart, Rosenstein 1, D-70191 Stuttgart, Germany; e-mail: rossano1973@gmail.com

�Bernard Price Institute for Palaeontological Research, School of Geosciences, University of Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa

Typescript received 31 August 2005; accepted in revised form 13 December 2006

Abstract: Dicynodont therapsids were near-ubiquitous

components of Permo-Triassic terrestrial faunas, but the

morphology of many of the nominal species remains poorly

understood. Here we provide a detailed redescription of the

cranium of the poorly known Dolichuranus primaevus from

the Middle Triassic Omingonde Formation of Namibia,

based on both the holotype and previously undescribed

referred specimens. We identify a number of autapomorphic

characters of D. primaevus and provide a revised taxon diag-

nosis. A phylogenetic analysis of Permian and Triassic

dicynodonts indicates that most Triassic dicynodonts form a

monophyletic clade. Within the Triassic clade Kannemeye-

rioidea, Dolichuranus is the sister taxon of a clade consisting

of the stahleckeriids Stahleckeria and Ischigualastia from the

Middle and Upper Triassic of South America, respectively.

Key words: dicynodonts, Dolichuranus, Namibia, phylog-

eny, Triassic.

Dicynodontia was a large and diverse group of pre-

dominantly herbivorous therapsids that arose in the Mid-

dle Permian (King 1988, 1990). They attained their peak

diversity and a cosmopolitan distribution in the Late

Permian, declined dramatically in the wake of the Permo-

Triassic boundary (PTB) mass extinction event, had a

resurgence in the Middle Triassic, and finally became

extinct in the Late Triassic (King 1988). The dicynodonts

were the major herbivores during the Late Permian and

for much of the Triassic (King 1990). Their success has

been attributed by Watson (1948) and others to their

unique sliding quadrate-articular jaw joint, which allowed

them to shear and ⁄or grind plant material with great effi-

ciency (Crompton and Hotton 1967; King et al. 1989;

Renaut 2000).

The faunal turnover across the PTB has led many

workers to regard dicynodonts as consisting of two

distinct groups: Permian dicynodonts and Triassic

dicynodonts, the latter broadly consisting of the Lystro-

sauridae and the Kannemeyeriiformes (sensu Maisch

2001). This division is reflected in the evolutionary

trends that were noted by Keyser (1974), such as an

increase in the relative length of the snout and second-

ary palate, a reduction in size of the interpterygoid

vacuity combined with its posterior migration out of the

choana, and the loss of the ectopterygoid and the

quadrate foramen. Consequently, separate phylogenies

for Permian and Triassic dicynodonts have been gener-

ated, but the phylogenetic relationships of dicynodonts

remain problematic. Most of the phylogenies utilize

predominantly cranial characters, because, with few

exceptions (e.g. Cruickshank 1967; Cox 1969; King 1981;

Vega-Dias and Schultz 2004; Surkov et al. 2005), the

postcranial material is not well known or has been

largely ignored. More importantly, dicynodont taxonomy

is over-split (e.g. King 1993) owing to a poor under-

standing of intraspecific, ontogenetic (e.g. Renaut 2000),

sexually dimorphic (e.g. Cruickshank 1967) or, in partic-

ular, distortion-related variation (e.g. Renaut 2000; Angi-

elczyk 2001). Indeed, all dicynodont skulls are highly

susceptible to distortion due to their sutural morpho-

logy, which consists predominantly of scarf ⁄ squamous

joints (Renaut 2000). Although this type of suture forms

a strong joint, it does allow different bone elements to

slide across each other, and may result in changes to the

size, shape or arrangement of various cranial elements,

sometimes within the same skull. A number of clado-

grams illustrating the relationships of dicynodonts have

been published (King 1988, 1990; Cox 1998; Surkov

2000; Angielczyk 2001; Maisch 2001, 2002a; Angielczyk

P A L A 7 2 7 B Dispatch: 24.8.07 Journal: PALA CE: Blackwell

Journal Name Manuscript No. Author Received: No. of pages: 17 PE: Raymond

[Palaeontology, 2007, pp. 1–17]

The Palaeontological Association doi: 10.1111/j.1475-4983.2007.00727.x 1

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and Kurkin 2003; Vega-Dias et al. 2004; Surkov et al.

2005), although few of these have incorporated a broad

range of both Permian and Triassic taxa.

Keyser (1973) described two medium to large dicyno-

dont skulls from the Omingonde Formation (Middle

Triassic) at Mount Etjo, Namibia, which he named Doli-

churanus primaevus and Rhopalorhinus etionensis. The

former he identified as a stahleckeriid and the latter as

a shansiodontid. In the same paper, Keyser (1973)

transferred Kannemeyeria latirostris, from the N’tawere

Formation of Zambia (Crozier 1970), to the genus Doli-

churanus. However, we do not consider D. latirostris to

be referable to Dolichuranus, as will be discussed in a

forthcoming publication. In their review of Triassic

dicynodont taxonomy, Keyser and Cruickshank (1979)

considered Rhopalorhinus a junior synonym of Dolichur-

anus, based largely on the discovery of additional mate-

rial at Mount Etjo, which was never formally described.

Keyser and Cruickshank (1979) therefore recognized two

species of Dolichuranus: D. primaevus and D. etionensis.

The latter species was subsequently placed in synonymy

with D. primaevus (Brink and Keyser 1986). The purpose

of this paper is to describe the cranial anatomy of

D. primaevus in detail based largely on the undescribed

specimens mentioned by Keyser and Cruickshank

(1979). Undescribed postcranial material associated with

these specimens is described elsewhere (Govender 2005).

This paper also aims to determine the phylogenetic

position of D. primaevus by incorporating it into a

data matrix of Permian and Triassic dicynodonts syn-

thesized from Angielczyk (2001) and Maisch (2001),

respectively.

Institutional abbreviations. BP, Bernard Price Institute for Palae-

ontological Research, University of the Witwatersrand, Johannes-

burg; CGP, Council for Geoscience, Pretoria; MCZ, Museo

Argentino de Ciencias Naturales, Buenos Aires; NM, National

Museum, Bloemfontein; PVL, Palaeontologia de Vertebrados,

Fundacion Miguel Lillo, San Miguel de Tucuman; RC, Rubidge

Collection, Wellwood, Graaff-Reinet; SAM, Iziko: South African

Museum, Cape Town; UMZC, University Museum of Zoology,

Cambridge.

Anatomical abbreviations. ang, angular; aos, antorbital sulcus;

ar, articular; b, boss; bo, basioccipital; bot, basioccipital tubera;

cd, circular depression; d, dentary; ec, ectopterygoid; eo, exoc-

cipital; ept, epipterygoid; f, frontal; fm, foramen magnum; icf,

internal carotid foramen; ip, interparietal; j, jugal; jf, jugular

foramen; la, lacrimal; laf, lacrimal foramen; lf, labial fossa; lpf,

lateral palatal foramen; mf, mandibular fenestra; mx, maxilla; n,

nasal; nb, nasal boss; op, opisthotic; p, parietal; pa, palatine; pbs,

parabasisphenoid; pdm, processus depressor mandibulae; pf, pre-

frontal; pmx, premaxilla; po, postorbital; ppd, palatal pad; pro,

prootic; prp, preparietal; psq, parietal flange of squamosal; pt,

pterygoid; ptf, post temporal fenestra; ptfr, recess of post tempo-

ral fenestra; q, quadrate; qf, quadrate foramen; qj, quadratojugal;

qsq, quadrate flange of squamosal; rarp, retroarticular process;

smx, septomaxilla; so, supraoccipital; sp., splenial; sq, squamosal;

t, tabular; v, vomer; vii, foramen for palatal branch of facial

nerve VII; vtr, ventral tympanic ridge; zsq, zygomatic flange of

squamosal.

GEOLOGICAL SETTING

The Karoo Supergroup in southern Africa occurs in the

extensive Main Karoo and Kalahari basins, as well as in

a number of subsidiary basins (Johnson et al. 1996).

One such basin is the Waterberg Basin of north-central

Namibia (Johnson et al. 1996; Smith and Swart 2002).

The Waterberg Basin comprises, from oldest to youngest:

the Tevrede, Omingonde and Etjo formations (Johnson

et al. 1996). The Omingonde Formation is a typical

non-marine red-bed sequence that was deposited in a

series of north-east ⁄ south-west-trending transfer grabens

that are associated with the prerifting tectonics of the

South Atlantic (Smith and Swart 2002). The Omingonde

Formation crops out extensively south of the Waterberg

thrust in the Otjiwarongo, Grootfontein and Omaruru

districts of Namibia (Pickford 1995). Three facies have

been identified for the formation, and they show a

sequence of increasing aridity through time (Smith and

Swart 2002). The Omingonde Formation is generally

regarded as being Middle Triassic in age (e.g. Smith and

Swart 2002), and has been correlated with the Cynogna-

thus Assemblage Zone (CAZ) of the Burgersdorp Forma-

tion, Beaufort Group, South Africa (Keyser 1973;

Pickford 1995). Recently, the CAZ was informally subdi-

vided (Hancox et al. 1995) into three subzones that

range in age from late Early Triassic (Upper Olenekian)

to early Middle Triassic (Anisian), so that the exact

subzone(s) with which the Omingonde Formation is

correlated is uncertain.

A rich vertebrate fauna has been described from the

Omingonde Formation outcropping on the slopes of

Mount Etjo in the Otjiwarongo District (Keyser 1973;

Pickford 1995; Smith and Swart 2002). It includes an

undescribed temnospondyl (Keyser 1973), the archo-

sauriform Erythrosuchus (Pickford 1995; Smith and

Swart 2002), the cynodonts Cynognathus, Diademodon

and Trirachodon (Keyser 1973; Smith and Swart 2002),

the therocephalian Herpetogale (Keyser 1973), and the

dicynodonts Dolichuranus (Keyser 1973) and Kannem-

eyeria (Keyser 1973; Smith and Swart 2002; Renaut

et al. 2003). Based on the co-occurrence of Kannemeye-

ria and Erythrosuchus in subzone B of the CAZ, the

Omingonde Formation may be broadly assigned an

Anisian age.

2 PALAEONTOLOGY

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SYSTEMATIC PALAEONTOLOGY

THERAPSIDA Broom, 1905

ANOMODONTIA Owen, 1859

DICYNODONTIA Owen, 1859

DOLICHURANUS Keyser, 1973

1973 Rhopalorhinus Keyser, p. 4, fig. 5.

Type species. Dolichuranus primaevus Keyser, 1973.

Revised diagnosis. Distinguished from all other dic-

ynodonts by the following combination of characters.

Autapomorphic characters: broad, trough-like depression

on tip of snout; ventral margin of vomers almost level

with pterygoids; moderately sized interpterygoid vacuity

positioned posterior to choana and within pterygoid cor-

pus; ventral tympanic ridge well developed into crest;

prominent processus depressor mandibulae on well-

developed ventral tympanic ridge. Apomorphic charac-

ters: alveolar margin straight, resulting in lateral exposure

of anterior parallel ridges of secondary palate; margins of

interpterygoid vacuity extended ventrally to form a high

torus; well-developed caniniform process with shallow

furrow on posteroventral surface; well-developed tusks

directed posteroventrally; paired nasal bosses present;

antorbital sulcus present; frontal extends onto intertem-

poral bar posterior to sunken pineal foramen; narrow

intertemporal bar; dorsal exposure of parietal level with

postorbital along intertemporal bar; short temporal

fenestrae; broad occiput; post-temporal fenestra posi-

tioned high on occiput. Plesiomorphic characters: ectop-

terygoid present; postorbital possesses a well-developed

footplate that contributes to suborbital bar anteriorly;

secondary palate intruded posteriorly by anterior exten-

sions of choana beyond palatal pads; maxilla contacts

choana.

Dolichuranus primaevus Keyser, 1973

Text-figures 1–4

1973 Rhopalorhinus etionensis Keyser, p. 4, fig. 5.

1979 Dolichuranus etionensis Keyser; Keyser and

Cruickshank, p. 96.

Holotype. CGP ⁄ 1 ⁄ 711 (formerly R334), a nearly complete skull

with articulated lower jaws.

Type locality and horizon. From the southern slopes of a hill

north of Mount Etjo, Renosterfontein, Kalkfeld, Otjiwarongo

District, Namibia (Brink and Keyser 1986). Keyser (1973, p. 3)

noted the horizon as ‘below the lowermost arenaceous horizon’

of the Omingonde Formation, Karoo Supergroup, Waterberg

Basin; Middle Triassic, probably Anisian.

Referred material. CGP ⁄ 1 ⁄ 712 (formerly R320), a partial skull,

the holotype of ‘Rhopalorhinus etionensis’ (Keyser 1973), from

the northern slopes of Mount Etjo, Renosterfontein, Kalkfeld,

Otjiwarongo District, Namibia; horizon given as ‘between the

upper and lower arenaceous horizon’ of the Omingonde Forma-

tion by Keyser (1973, p. 4). The following, previously unde-

scribed, specimens are also referable to D. primaevus:

CGP ⁄ 1 ⁄ 713, 714, BP ⁄ 1 ⁄ 4569, 4570, 4573, 4577, 4578. All of

these are fragmentary, partial or complete skulls that were col-

lected from the Omingonde Formation of Mount Etjo by A. W.

Keyser, J. W. Kitching and A. R. I. Cruickshank in 1974.

Diagnosis. As for genus.

Description

The following is a composite description of the cranial anat-

omy of Dolichuranus primaevus based on the holotype and

referred material listed above. The skulls are all presumed to

be adult based on their large size, their well-ossified sutures

and the extensive overlapping of bones. They range from 320

to 490 mm in length, although less complete remains (e.g.

BP ⁄ 1 ⁄ 4577) indicate that the taxon could have attained an

even greater skull size. All the specimens show some degree of

distortion. In dorsal view, the most complete crania

(CGP ⁄ 1 ⁄ 711, 714, BP ⁄ 1 ⁄ 4570, 4573) are elongated and trian-

gular in outline. The occiputs are broad, but their widths are

less than the total skull length, and the preorbital length of the

skull is greater than the postorbital length. The snout morphol-

ogy, including the tusks, is best preserved in BP ⁄ 1 ⁄ 4577 and

CGP ⁄ 1 ⁄ 714. The more horizontal orientation of the snout, in

contrast to the downwardly curved ‘beak’ in Daptocephalus

leoniceps (Ewer 1961; Cluver and Hotton 1981) and Kannem-

eyeria (Renaut 2000), contributes to the appearance of a long

snout. Note that, based on observations by two of us (AR and

JH), we tentatively regard Daptocephalus as a distinct taxon

rather than as a subjective junior synonym of Dicynodon, con-

tra Cluver and Hotton (1981).

Skull roof. The surface of the snout (Text-figs 1A–D, 2A–D, 4A–

D) exhibits a rough, pitted surface texture on the premaxilla, the

maxilla (especially on the ventral and posterior surfaces of

the caniniform processes), the palatal surface of the snout, and

the nasal bosses. This surface texture, which characterizes many

dicynodonts, is thought to represent the extent of horn-covering

in life (Crompton and Hotton 1967; Cluver 1971; King 1981,

1988; Renaut 2000).

The premaxilla is relatively larger than that of Kannemeyeria

(Renaut and Hancox 2001). Brink and Keyser (1986) mentioned

a low, dorsomedian ridge on the premaxilla; however, this fea-

ture represents the natural doming of the premaxilla, the appear-

ance of which is exaggerated by the presence of nasal bosses.

Moreover, any bilateral compression of the skull would further

DAMIANI ET AL . : TRIASS IC ANOMODONT SYNAPSID FROM NAMIBIA 3

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A B

C D

E F

TEXT -F IG . 1 . Dolichuranus primaevus Keyser, 1973, holotype skull CGP ⁄ 1 ⁄ 711. A–B, photograph and interpretive drawing of skull

roof. C–D, photograph and interpretive drawing in left lateral view. E–F, photograph and interpretive drawing of palate. Grey shading

represents matrix; unstippled areas represent plaster or broken bone.

4 PALAEONTOLOGY

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exaggerate the appearance of a dorsomedian ridge on the pre-

maxilla, as in CGP ⁄ 1 ⁄ 711. The nasal bosses are large, elongated

and laterally placed, so that they extensively overhang the lateral

surface of the snout (Text-figs 1B, 2B, 4B). This exaggerates the

depth of the narial recess beneath the bosses.

The alveolar margin, between the caniniform process of the

maxilla and the tip of the snout, is similar to that of Ischigualas-

tia (Cox 1965) in being straight rather than curved, so that the

anterior parallel ridges of the palate are partially exposed in pro-

file (Text-figs 1C–D, 4C–D). At the tip of the snout, the alveolar

margin of the premaxilla is emarginated between the anterior

parallel ridges. Above this emargination, there is a broad trough,

the function of which is uncertain. This feature seems to be

autapomorphic for Dolichuranus primaevus.

Ventrolaterally, the maxilla has a distinct anterior process that

projects into the premaxilla, but is nevertheless excluded from,

or makes only point contact with, the margin of the naris (Text-

figs 1D, 2D, 4D). In contrast, the maxilla forms a significant part

of the narial margin in Kannemeyeria (Renaut 2000). The lateral

surface of the maxilla anterior to the caniniform process is shal-

lowly concave. The maxilla contributes posteriorly to the ante-

rior part of the suborbital bar of the zygomatic arch, and there

is a distinct notch between the zygomatic arch and the canini-

form process. The caniniform process is more laterally developed

than that of Daptocephalus, developing into a distinct buttress.

However, the buttress formed by the caniniform process is less

developed laterally than that of Kannemeyeria. In smaller speci-

mens the nasal bosses are less developed and the caniniform

processes can be partially seen in dorsal view, whereas in larger

specimens the nasal bosses are more strongly developed and the

caniniform processes are obscured. The canines are well devel-

oped and circular in cross-section. However, they do not erupt

anteroventrally in line with the caniniform processes as in Kan-

nemeyeria. Instead, they are directed strongly posteriorly. Most

of the surface features (e.g. wear striations) of the tusks are

obscured by a layer of consolidant. However, there is a pro-

nounced wear facet that occupies the entire posterior surface of

the tusk and is orientated slightly medially. This wear facet may

indicate a posteriorly directed raking action against the substrate

during feeding.

The septomaxilla (Text-figs 1D, 2D, 4D) is located within the

narial recess. It is much larger than that of Kannemeyeria, but

similar in relative size to that of Daptocephalus (Ewer 1961). It

forms the posterior border of the external naris. The anterior

margin of the septomaxilla has three processes: dorsal, middle

and ventral. As in Daptocephalus, the septomaxilla has a complex

series of depressions and ridges, but these are not as well devel-

oped. A foramen along the septomaxilla-maxilla contact has

been observed in a number of Triassic dicyndonts (Cluver 1971;

Renaut and Hancox 2001), but no foramina are visible in Doli-

churanus. There is no contact between the septomaxilla and the

lacrimal, because of a short contact between the nasal and the

maxilla. This contact corresponds to a ridge between the anterior

orbital margin and the posterodorsal margin of the naris.

The lacrimal (Text-figs 1D, 2D) is large and triangular, and

occupies most of the anterior margin of the orbits. The lacrimal

foramen is visible only in BP ⁄ 1 ⁄ 4573 (Text-fig. 2D). An antor-

bital sulcus (Renaut 2000) is formed on the lacrimal by the

overhang of the dorsal orbital ledge, which consists mainly of

the prefrontal. The prefrontal is small, but not as small as in

Kannemeyeria. It is restricted to the anterodorsal margin of the

orbit where it forms a distinct ledge. However, in some speci-

mens (e.g. BP ⁄ 1 ⁄ 4570, CGP ⁄ 1 ⁄ 714) the dorsal skull roof has

been sheared laterally so that the prefrontal on the side opposite

the direction of shear is fairly large and extends medially, i.e. the

prefrontal has an exaggerated dorsal exposure. The ventral rim

of the orbit is formed by the jugal. The jugal has narrow lateral

exposure along the dorsal surface of the suborbital bar, but it

has broad exposure medially and ventrally. The jugal extends

posteriorly along the zygomatic arch and terminates before the

point where the squamosal flares into its zygomatic flange.

The frontal has a relatively broad contribution to the dorsal

margin of the orbit (Text-figs 1B, 2B, 4B), similar to that seen

in Kannemeyeria. Its anterior border with the nasals is more or

less transverse, and it continues along the posterior border of

the prefrontals. Posteriorly, the frontal follows the postorbitals

medially and posteriorly onto the intertemporal bar. It has a

posterior process that projects beyond the posterior margin of

the pineal foramen, but not to the same degree as Kannemeyeria

(Renaut 2000). The frontal does not contact the margin of the

pineal foramen at any point, but is separated from it by the

preparietal anteriorly, and by the parietal posteriorly.

The posterodorsal and posterior margin of the orbit is formed

by the slender postorbital (Text-figs 1D, 2D, 4D). It has a broad

footplate that extends anteriorly along the suborbital bar. Pos-

terodorsal to the orbit, the postorbital extends medially and

forms a pronounced ridge along its anterior margin that paral-

lels the margin of the temporal fenestra. This ridge continues

along the anterior part of the intertemporal bar, terminating just

posterior to the pineal foramen. The postorbital continues poste-

riorly as the dorsolateral wall of the intertemporal bar. The post-

orbital contacts the interparietal and the parietal flange of the

squamosal posterior to the temporal fenestra. The temporal

fenestrae are anteroposteriorly short, like those of Stahleckeria

(Maisch 2001).

The small, elliptical preparietal (Text-figs 1B, 2B, 4B) forms

the anterior and the anterolateral margins of the pineal foramen.

The pineal foramen is situated within a relatively deep depres-

sion below the frontals and the parietals at the base of the inter-

temporal bar. Some specimens (e.g. BP ⁄ 1 ⁄ 4570, CGP ⁄ 1 ⁄ 714)

exhibit a low boss in front of the preparietal on the median

suture between the frontals. The suture pattern on the prepineal

boss is strongly interdigitated.

The parietals (Text-figs 1B, 2B, 4B) form the posterior and

posterolateral margin of the pineal foramen. They rise rapidly

from the pineal foramen posteriorly and continue as the dorsal

surface of the narrow intertemporal bar, level with the post-

orbitals (Text-fig. 2D). This is markedly different from Dapto-

cephalus and Kannemeyeria, where the parietals form the floor

of a groove along the dorsal surface of the intertemporal bar.

Posteriorly the parietals continue to increase in height along

the intertemporal bar until they are just above the postorbitals.

The parietals contact the interparietal at the posterior margin

of the intertemporal bar. The interparietal separates the parie-

tals from the squamosal, except for a point contact postero-

laterally.

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The squamosals have the typical triradiate morphology of all

dicynodonts: a slender zygomatic flange; a parietal flange, which

is well developed laterally; and a quadrate flange, which is well

developed laterally and, in particular, ventrally (Text-figs 1B, D,

2B, D). In overall morphology and degree of lateral flaring, the

squamosals are more similar to those of Daptocephalus than

Kannemeyeria. The zygomatic flange of the squamosal has an

anterior extension onto the suborbital bar that contacts the foot-

plate of the postorbital. It is clasped anteriorly by the split pos-

terior extension of the maxilla onto the suborbital bar. In dorsal

view, the zygomatic arches are relatively straight, although in

specimens where there is anteroposterior compression, the zygo-

matic arches bow laterally.

Palate. The bony secondary palate (Text-figs 1E–F, 2E–F,

4E–F), which is largely formed by the premaxilla, is very long

compared with both Daptocephalus and Kannemeyeria, and it

extends posteriorly to at least level with the anterior margin of

the orbits. Its total length is equal to, or slightly greater than,

that of the pterygoid girder. The alveolar margin of the pre-

maxilla does not form a cup-shaped rim enclosing the second-

ary palate anteriorly. The anterior parallel ridges of the

secondary palate are well developed and project anteriorly

beyond the emarginated alveolar margin. In between the ante-

rior ridges, there are three, well-defined grooves: a median

groove and two lateral grooves. The posterior medial ridge of

the secondary palate is largely composed of the fused vomers,

which are overlapped anteriorly by the premaxillae. Immediately

posterior to the premaxilla-vomer contact, there is a notable

lateral expansion of the vomers. The high posterior medial

ridge becomes rapidly reduced in its ventral development ante-

riorly. Lateral to the posterior medial ridge, there is a shallow,

trough-like depression.

The posteroventral surface of the caniniform process is

marked by a shallow furrow. A medial projection of the maxilla

contacts the anterolateral margin of the choana. It separates the

premaxilla from contacting the palatal pads of the palatine. The

premaxilla itself contacts the anterior margin of the choana.

Posterolateral to the caniniforms, a relatively small labial fossa

(Text-fig. 1D, 1F, 2F, 4D, F) is bounded by the maxilla, the pala-

tine and the jugal. Depending upon distortion, the contribution

of the jugal varies from extensive to a point contact.

The palatoquadrate region is long and moderately wide, but

not as wide as in Kannemeyeria. The choanae are long, narrow

and deep. They are bounded by the anterior rami of the pteryg-

oids, which are ventrally developed beyond the level of the other

palatal elements. The choanae have narrow anterior extensions

that intrude into the posterior margin of the secondary palate.

These extensions project beyond the palatal pads of the palatines

and, thus, are not solely the result of medial development of the

palatal pads into the choanae. BP ⁄ 1 ⁄ 4570, CGP ⁄ 1 ⁄ 711 and

CGP ⁄ 1 ⁄ 714 do not appear to have these anterior extensions of

the choanae probably because they have been obliterated by

anteroposterior compression.

The palatal pads of the palatines (sensu Cox 1998; Text-figs

1F, 2F, 4F) are larger and more strongly developed than those of

Daptocephalus and Kannemeyeria. They have a rugose surface

texture, and also a greater medial expansion anteriorly, giving

them a teardrop shape. The lateral palatal fossa is anteroposteri-

orly elongate. It is located posteriorly and laterally against the

pterygoids at the point where the width of the palatal pads

decreases posteriorly.

On the anterolateral surface of the pterygoid girder, there is a

small, tongue-shaped ectopterygoid (Text-figs 1D, 2F, 4D, F)

that is level with the labial fossa and continues anteriorly onto

the posterior surface of the maxilla. The ectopterygoid is

bounded by the palatine posterodorsally, the pterygoid postero-

ventrally and the maxilla anteriorly. The maxilla does have a

short posterior process anteroventral to the ectopterygoid, but it

does not contact the lateral surface of the pterygoids.

The vomer (Text-figs 1F, 2F, 4F) forms a thin, blade-like plate

anteriorly, the ventral margin of which is almost level with the

pterygoids. Posteriorly it bifurcates to form the anterior and lat-

eral walls of the interpterygoid vacuity. The margins of the vacu-

ity are extended ventrally to form a high torus (Surkov and

Benton 2004) that is inclined medially so as to enclose the vacu-

ity partially. A high torus is also present in a specimen of Rec-

hnisaurus cristarhynchus (Surkov and Benton 2004) but its

morphology is unlike that of Dolichuranus primaevus. The

interpterygoid vacuity of D. primaevus is larger than that of a

similarly sized Kannemeyeria, but comparable in relative size to

that of Daptocephalus. Unusually, the interpterygoid vacuity is

located posterior to the choana within the pterygoid corpus, and

extends into the anterior half of the parabasisphenoid complex.

The cultriform process, which is exposed only in CGP ⁄ 1 ⁄ 713, is

an extemely thin blade of bone, unlike that of Kannemeyeria.

The parabasisphenoid (Text-figs 1F, 2F, 4F) is a broad ele-

ment that is strongly emarginated anteriorly by the interpteryg-

oid vacuity. The foramen for the palatal branch of the facial

nerve is located at the junction between the pterygoid, the

parabasisphenoid and the torus of the interpterygoid vacuity.

Posterior to this foramen is another smaller foramen for the

internal carotid canal. This foramen is immediately posterolat-

eral to the posterior tips of the torus. The parabasisphenoid also

contributes posteriorly to the anterior margins of the basioccipi-

tal tubera, which are relatively short but broad, as in Daptoceph-

alus. The parabasisphenoid is dorsal to the basioccipital. Just

posterior to the suture between the parabasisphenoid and the

basioccipital there is an unusual circular depression, the function

of which remains uncertain; a similar depression is present but

was not described (M. W. Maisch, pers. comm. 2006) in Kit-

chinganomodon crassus (Maisch 2002b). Posterior to this depres-

sion and in between the basioccipital tubera, there is a low

intertuberal ridge.

Most of the basicranial structure is obscured by matrix. How-

ever, the footplate and the lower part of the ascending ramus of

the epipterygoid are exposed laterally (Text-figs 1D, 2D). There

does not appear to be an anterior extension of the epipterygoid

footplate, as in Daptocephalus (Ewer 1961).

The quadrate forms the double condyle typical of dic-

ynodonts (Text-figs 1F, 2F). Both condyles are similar in size.

The quadrate is loosely clasped by the quadratojugal, which

forms a dorsally extended plate over the squamosal anteriorly

and a transverse ledge on the ventral margin of the quadrate

flange of the squamosal posteriorly. Anteriorly, in the quadrate-

quadratojugal suture, there is a well-defined quadrate foramen.

6 PALAEONTOLOGY

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A B

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TEXT -F IG . 2 . Dolichuranus primaevus Keyser, 1973, referred specimen BP ⁄ 1 ⁄ 4573. A–B, photograph and interpretive drawing of

skull roof. C–D, photograph and interpretive drawing in left lateral view. E–F, photograph and interpretive drawing of palate. G–H,

photograph and interpretive drawing of occiput. Grey shading represents matrix; unstippled areas represent plaster or broken bone.

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This foramen is also exposed posteroventrally on the occiput.

The quadrate ramus of the pterygoid contacts both the quad-

rate and the paroccipital process of the opisthotic, as in

Kannemeyeria.

Occiput. The lateral flaring of the quadrate flange of the squa-

mosal beyond the zygomatic arch, as well as the long, deep

parietal flange of the squamosal, results in a broad occiput

(Text-fig. 3). The dorsolateral notch (sensu Angielczyk 2001) is

formed by the dorsal placement of the zygomatic flange of the

squamosal above the rest of the squamosal. The occiput is also

fairly deep owing to the ventral development of the quadrate

flange of the squamosal beyond the basioccipital tubera to the

level of the quadrate. Thus, the suspensorium is tall.

The interparietal has a narrow dorsal exposure on the skull

roof (Text-figs 1B, 2B, 2H, 4B). There is also a short, narrow

anterior process of the interparietal between the parietals on the

intertemporal bar. On the interparietal, a well-developed nuchal

groove descends from a pronounced notch on the posterior

margin of the intertemporal bar. The interparietal is a triangular

element that extends ventrally to emarginate the mid-dorsal

margin of the supraoccipital. The ventral tip of the interparietal

is indented.

The tabulars are present as triangular elements posterior to

the parietal flange of the squamosal, lateral to the interparietal

and dorsal to the supraoccipital. The large supraoccipital is later-

ally extensive and wing-shaped. It forms the dorsal rim of the

post-temporal fenestrae and the foramen magnum, and inter-

poses between the tabulars and the post-temporal fenestrae. The

supraoccipital ridge is thick and well developed. It rises dorsolat-

erally from well-developed atlantal facets of the exoccipital. The

supraoccipital ridge marks the boundary between a shallow dor-

sal recess occupied by the interparietal, the tabulars, and the

supraoccipital, and the deep recess of the post-temporal fenes-

trae ventrally. The recess of the post-temporal fenestra is deeper

than that of Kannemeyeria. The post-temporal fenestrae them-

selves are deeply positioned within the recess at the junction

between the supraoccipital ridge and the ventral tympanic ridge.

Thus, the post-temporal fenestrae are high above the level of the

occipital condyle, about level with the dorsal margin of the fora-

men magnum. This is similar to the condition in Jachaleria

(Vega-Dias and Schultz 2004).

The basioccipital condyle is distinctly trilobate, with the

upper lateral lobes of the exoccipital separated from the lower

median lobe of the basioccipital by a groove (Text-fig. 3). The

lateral lobes of the exoccipital are themselves separated by a

dorsoventral constriction. However, the sutures between the

exoccipitals and the basioccipital are indeterminate. The jugular

foramen is situated lateral and slightly ventral to the occipital

condyle.

The medial tympanic ridge of the opisthotic is rather indis-

tinct compared with that seen in Kannemeyeria and Daptoceph-

alus. It meets the ventral tympanic ridge laterally and the two

ridges form a prominent, well-developed processus depressor

mandibulae (Renaut 2000), also referred to as the tympanic pro-

cess of the opisthotic (Cluver 1971). The ventral tympanic ridge

is well developed into a crest. It forms, together with the supra-

occipital ridge, the deep recess of the post-temporal fenestra.

Mandible. The mandible is best preserved in CGP ⁄ 1 ⁄ 711 (Text-

fig. 1C–F), the complete left ramus being 255 mm in total length

and 84 mm at its deepest point at the posterior end of the sym-

physeal region. As in all other dicynodonts the symphysis, which

is formed by the dentaries and the splenials, is completely

co-ossified. It is proportionally shorter and deeper than the sym-

physeal region of Kannemeyeria simocephalus. The posterior wall

of the symphysis appears to possess a simple, U-shaped vertical

sulcus between the mandibular rami that is not excavated by

any deep pits, unlike the condition in K. simocephalus

(BP ⁄ 1 ⁄ 4524). Ventrally there is a posteriorly extended symphy-

seal shelf. The anteroventral surface of the symphysis is quite

steep compared with K. simocephalus, and curved postero-

ventrally. A low median ridge that fades away ventrally marks

the midline of the anteroventral surface. The paramedian sulci

that are present in K. simocephalus are absent in CGP ⁄ 1 ⁄ 711,

although there is a vague fossa on each side of the median ridge

at its dorsal end. The anteroventral surface is produced dorsally

into a square-ended beak. There is no small median notch on

the beak but it must be noted that the tomial margin of the

beak is neither well preserved nor well prepared.

The anteroventral surface of the mandible is almost perpen-

dicular to the lateral mandibular surface and there is a promi-

nent, rounded, laterally projecting ridge where these two

surfaces meet. The dentary tables lie dorsally, just posterior to

the tomial margin of the beak. Each table is narrow and is

angled strongly dorsolaterally; its lateral and medial margins

border a poorly defined, shallow sulcus, unlike the well-defined

sulcus bordered by prominent ridges in Kannemeyeria simoceph-

alus. It is possible, however, that the ridges were lost during

preparation. The intertabular sulcus, or median dentary sulcus,

is a U-shaped groove, as in K. simocephalus. Although the

A

B

TEXT -F IG . 3 . Dolichuranus primaevus Keyser, 1973, referred

specimen BP ⁄ 1 ⁄ 4573. A–B, photograph and interpretive drawing

of occiput. Grey shading represents matrix; unstippled areas

represent plaster or broken bone.

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occlusal area posterior to the dentary tables is partially

obscured by matrix, it is clear that the dentary was produced

into a single, sharply edged dorsal crest above the external

mandibular fenestra, whereas in K. simocephalus there is a dor-

solateral ridge separated from a taller dorsomedial crest by a

longitudinal sulcus in this region. In any case the dorsal sulcus

would be far less extensive than that of K. simocephalus, if it is

present at all.

Laterally (Text-fig. 1C–D) the dentary presents a markedly

different shape to that of Kannemeyeria simocephalus or Rhachio-

cephalus magnus (Maisch 2003). In those taxa the dentary is dee-

ply bifurcate posteriorly, with the triangular ventral ramus

A

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D

B E

F

TEXT -F IG . 4 . Dolichuranus primaevus Keyser, 1973, referred specimen CGP ⁄ 1 ⁄ 712 (holotype of ‘Rhopalorhinus etionensis’). A–B,

photograph and interpretive drawing of skull roof. C–D, photograph and interpretive drawing in left lateral view. E–F, photograph

and interpretive drawing of palate. Grey shading represents matrix; and unstippled areas represent plaster or broken bone.

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deeply incised into the angular. In contrast, the ventral ramus of

CGP ⁄ 1 ⁄ 711 forms only a short projection from the base of the

emargination between the dorsal and ventral rami, so that the

posterior margin of the dentary in lateral view is not so much

bifurcate as stepped. A further difference from K. simocephalus is

the absence of an elongate tubercle that projects laterally from

the ventral margin of the dentary at the base of the ventral

ramus. A broad, shallow emargination separates the short ventral

ramus from the large dorsal ramus. The dorsal ramus forms the

dorsal margin of the slot-shaped external mandibular fenestra.

The fenestra curves dorsally at its posterior end where the dorsal

posterior ramus of the dentary shallows and the angular deep-

ens. The posterior tip of the dorsal posterior ramus meets the

postlaminar process of the angular, thus excluding the surangu-

lar from the margin of the external mandibular fenestra.

The angular has gently concave ventral and dorsal margins,

resulting in dorsoventrally expanded anterior and posterior ends.

The anterior expansion is not as deep as that of the posterior end.

It is divided into two anterior rami: the dorsal ramus is short and

triangular, and curves dorsally partially to fill the emargination

between the two posterior rami of the dentary; the long, shallow,

ventral ramus continues underneath the dentary, forming the ven-

tral margin of the mandible, almost to the level of the symphysis.

The large reflected lamina forms the majority of the depth of the

angular posterior to the external mandibular fenestra. It is

expanded ventrally so that it projects below the ventral margin of

the prearticular, but it does not curve medially to wrap partially

the ventral margin of the mandible as it does in Rhachiocephalus

magnus (Maisch 2003). The postlaminar region of the angular is

reduced compared with R. magnus and Kannemeyeria simocepha-

lus. It forms a narrow posterodorsally curved spur that articulates

with the dentary and the surangular dorsally.

Because the surangular is incomplete, it is not possible to

determine whether it was fused to the articular as in most dic-

ynodonts (Maisch 2003). As in Kannemeyeria simocephalus

(BP ⁄ 1 ⁄ 4524) it did not form a projecting shelf over its contact

with the angular, unlike the condition in Rhachiocephalus mag-

nus (Maisch 2003). The surangular forms a posterolaterally ori-

entated oblique suture with the dorsal posterior ramus of the

dentary so that its medial exposure is greater than its lateral

exposure. In medial view, the surangular forms a rounded bar

that overhangs the narrow adductor fossa.

As in all dicynodonts, the articular has an anteroposteriorly

convex articular surface that is divided by a trochlea into medial

and lateral condyles. The intercondylar trochlea, which forms a

tall ridge with a triangular cross-section, is particularly well

developed. The dorsoventrally flattened condyles are supported

below by a buttress that is formed from either the articular or a

fused composite of the articular and the surangular. The lateral

condyle is the longer of the two and forms a semicircle in ven-

tral view, whereas the medial condyle ends abruptly at its ante-

rior end giving it a hatchet-like shape.

The co-ossified splenials occupy the ventral two-thirds of the

posterior symphyseal surface. Each side of the splenial has two

posterior rami that extend along the medial surface of each

mandible. The ventral posterior ramus is the narrower and more

elongate of the two, inserting between the anterior ventral ramus

of the angular and the ventral margin of the prearticular poster-

ior to the posterior symphyseal wall. The dorsal ramus is

rounded in shape and broadly overlaps the anterior end of the

prearticular. As preserved, the prearticular is a simple, flattened,

strap-like bone on the medial surface that becomes deeper ante-

riorly. Its dorsal margin forms the medioventral margin of the

adductor fossa, whereas its ventral margin is extensively exposed

along the ventral margin of the mandible, except at the anterior

end where the splenial and the anterior ventral ramus of the

angular project ventral to it.

PHYLOGENETIC POSITION OFDOLICHURANUS

Methods

The phylogenetic relationships of Dolichuranus primaevus

among Triassic dicynodonts has been much debated. It

has variously been considered a shansiodontid (Cooper

1980; Lucas 1993), a stahleckeriid (Keyser 1973; Cox and

Li 1983; Surkov 2000), a kannemeyeriid (King 1988) or a

dinodontosaurid (Keyser and Cruickshank 1979), while

Maisch (2001) considered it incertae sedis within the

Dicynodontia. However, D. primaevus has never been

included in a formal phylogenetic analysis. The redes-

cription presented above provides the impetus for an

assessment of its phylogenetic position. Our analysis com-

plements those of previous analyses (Angielczyk 2001;

Maisch 2001, 2002a; Vega-Dias et al. 2004) but includes a

broader range of Permian and Triassic dicynodonts.

The phylogenetic analysis was based on a data matrix

consisting of 24 anomodont taxa and 56 morphological

characters. The basal anomodont Patranomodon was the

outgroup. The character list (see Appendix) was synthe-

sized largely from the work of Angielczyk (2001) for

Permian taxa and Maisch (2001) for Triassic taxa, in

some cases with modification. Additional characters are

from our unpublished work. The data matrix and sources

of information for character codings are given in the

Appendix. All of the characters in the analysis are cranial,

because the postcranium remains either poorly known or

undescribed for most of the taxa, including Dolichuranus.

The data matrix was analysed using the heuristic search

algorithm of PAUP 3.1 (Swofford 1993), with the follow-

ing settings in effect: the tree-bisection-reconnection

branch swapping algorithm was used and trees obtained

by the simple-stepwise-addition sequence, zero-length

branches were collapsed to yield polytomies, and all the

shortest trees were kept. Characters were optimized using

the delayed transformation algorithm (DELTRAN), multi-

state characters were treated as unordered, and all charac-

ters were equally weighted.

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Results

The analysis yielded 92 most parsimonious trees (MPTs),

each with a length of 238 steps, a consistency index of

0Æ42 and a retention index of 0Æ56. The fully resolved

cladogram in Text-figure 5A is our preferred phylogenetic

hypothesis, chosen from among the 92 MPTs based on a

posteriori assessment of character distribution (Carpenter

1988; Smith 1994). A 50 per cent majority rule tree is also

provided (Text-fig. 5B). A strict consensus of all MPTs

shows almost no internal resolution and is therefore not

considered further.

The topology of relationships among the Permian taxa

indicate support for some of the groupings found by pre-

vious analyses. In particular, our analysis supports a sis-

ter-group relationship between Diictodon and Robertia (¼

Robertiidae of King 1988; Angielczyk 2001; Angielczyk

and Kurkin 2003; Modesto et al. 2003), the relatively

basal position of Endothiodon (Angielczyk 2001; Angi-

elczyk and Kurkin 2003), and a sister-group relationship

A

B

TEXT -F IG . 5 . Cladograms illustrating hypotheses of relationships among a selection of well-known Permian and Triassic dicynodont

taxa, from a data matrix synthesized from Angielczyk (2001) and Maisch (2001). A, one of the 92 MPTs chosen as our preferred

phylogenetic hypothesis. B, 50 per cent majority-rule tree. Bold branches indicate exclusively Triassic taxa; Lystrosaurus occurs in both

the Permian and the Triassic and is indicated by a dashed line. Dolichuranus is the sister taxon of Stahleckeriidae. See text and

Appendix for details of analysis. Abbreviations: Kann, Kannemeyerioidea; Kannem, Kannemeyeriiformes; Shans, Shansiodontidae;

Stahl, Stahleckeriidae.

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between Myosaurus and Cistecephalus (Angielczyk 2001).

However, in our analysis, Dicynodon is nested within a

clade of Permian dicynodonts which includes Daptocepha-

lus, Aulacephalodon, Oudenodon and Pelanomodon. This

contrasts with previous analyses (Angielczyk 2001; Maisch

2002a; Angielczyk and Kurkin 2003; Surkov et al. 2005)

that suggest Dicynodon may be more closely related to

Triassic dicynodonts. The position of Lystrosaurus basal

to Dinanomodon and more derived Triassic dicynodonts

(Kannemeyeriiformes; see below) is consistent with previ-

ous analyses (Maisch 2002a; Surkov and Benton 2004;

Surkov et al. 2005).

Most of the Triassic dicynodonts in our analysis form a

clade, the Kannemeyeriiformes (Maisch 2001). In our pre-

ferred phylogenetic hypothesis (Text-fig. 5A), the Kanne-

meyeriiformes consists of two subclades: one has the

topology (Vinceria (‘Shansiodon’, Tetragonias)), and corre-

sponds to the Shansiodontidae of Cox (1965); the second

has the topology (Kannemeyeria (Dolichuranus (Ischigu-

alastia, Stahleckeria))), corresponding to the Kannemeye-

rioidea of Surkov (2000). The Permo-Triassic Lystrosaurus

and the Permian Dinanomodon are successive outgroups

to the Kannemeyeriiformes. In the 50 per cent majority

rule tree (Text-fig. 5B), the taxa Tetragonias, Vinceria and

‘Shansiodon’ instead form successively more derived taxa

relative to the Kannemeyerioidea.

In all MPTs, Dolichuranus is the sister taxon to the

stahleckeriids Stahleckeria and Ischigualastia from the

Ladinian and Carnian of South America, respectively.

The clade (Dolichuranus (Stahleckeria, Ischigualastia)) is

supported by the following synapomorphies, only the

first of which represents an ambiguous character state

change: presence of a nasal ⁄ lacrimal contact (character 5,

state 1); length of the internasal suture less than half the

length of the nasal (character 6, state 1); dorsal exposure

of parietals narrow and crested (character 16, state 2);

mid-ventral plate of vomers with expanded area posterior

to the junction with the premaxilla (character 39, state 0,

apomorphic reversal); and pterygoid process of the max-

illa absent on the lateral surface of the pterygoid girder

(character 47, state 0, apomorphic reversal). This result

supports Keyser’s (1973) initial assessment of the rela-

tionships of the species, as well as Surkov’s (2000) evolu-

tionary-systematic concept of Dolichuranus as an ancestor

of (i.e. sister taxon to) the Stahleckeriidae. Maisch (2001)

did not assign Dolichuranus to a clade of Triassic dic-

ynodonts largely because of the then inadequate state of

knowledge of that taxon. However, Maisch (2001,

p. 140) stated that ‘the ancestors of the stahleckeriids

went through an evolutionary stage similar to Kannem-

eyeria, with a narrow intertemporal skull roof and the

postorbitals tightly appressed to the parietals laterally …’.

Our phylogenetic results are in accordance with Maisch

(2001) in that the ‘ancestral’ stahleckeriid (Dolichuranus

in our analysis) shows strong phenetic similarity to

Kannemeyeria, as noted in the preceding description.

Acknowledgements. We are indebted to the curators at the fol-

lowing institutions for access to comparative material: BP, CGP,

MCZ, NM, PVL, RC, SAM and UMZC. We are also grateful to

J. Neveling (CGP) for specimen loans, J. L. Vasconcelos for

assistance in data capturing, and O. van Staaten for technical

assistance. We thank the reviewers, M. W. Maisch and J. Botha,

and the editor, S. P. Modesto, for critical comments on our

manuscript. Support for this project was provided by the Pala-

eoanthropology Scientific Trust, the National Research Founda-

tion of South Africa, and the University Research Council of the

University of the Witwatersrand. RD is supported by an Alexan-

der von Humboldt Research Fellowship.

REFERENCES

ANGIELCZYK, K. D. 2001. Preliminary phylogenetic analysis

and stratigraphic congruence of the dicynodont anomodonts

(Synapsida: Therapsida). Palaeontologia Africana, 37, 53–79.

—— and KURKIN, A. A. 2003. Phylogenetic analysis of

Russian Permian dicynodonts (Therapsida: Anomodontia):

implications for Permian biostratigraphy and Pangaean bioge-

ography. Zoological Journal of the Linnean Society, 139, 157–212.

BRINK, A. S. and KEYSER, A. W. 1986. Dolichuranus primae-

vus Keyser, 1973. In BRINK, A. S. (ed.). Illustrated biblio-

graphical catalogue of the Synapsida. Handbook of the

Geological Survey of South Africa 10-1, unpaginated.

BROOM, R. 1905. On the use of the term Anomodontia.

Records of the Albany Museum, 1, 266–269.

CARPENTER, J. M. 1988. Choosing among multiple equally

parsimonious cladograms. Cladistics, 4, 291–296.

CLUVER, M. A. 1971. The cranial morphology of the dicyno-

dont genus Lystrosaurus. Annals of the South African Museum,

56, 155–274.

—— and HOTTON, N. 1981. The genera Dicynodon and Diic-

todon and their bearing on the classification of the Dicyn-

odontia (Reptilia, Therapsida). Annals of the South African

Museum, 83, 99–273.

—— and KING, G. M. 1983. A reassessment of the relation-

ships of the Permian Dicynodontia (Reptilia, Therapsida) and

a new classification of the dicynodonts. Annals of the South

African Museum, 91, 195–273.

COOPER, M. R. 1980. ‘The origins and classification of Trias-

sic dicynodonts’ by A. W. Keyser and A. R. I. Cruickshank,

Discussion. Transactions of the Geological Society of South

Africa, 83, 107–111.

COX, C. B. 1965. New Triassic dicynodonts from South Amer-

ica, their origins and relationships. Philosophical Transactions

of the Royal Society of London, Series B, 248, 457–516.

—— 1969. Two new dicynodonts from the Triassic N’tawere

Formation, Zambia. Bulletin of the British Museum (Natural

History), Geology, 17, 255–294.

——1998. The jaw function and adaptive radiation of the dicyn-

odont mammal-like reptiles of the Karoo Basin of South

Africa. Zoological Journal of the Linnean Society, 122, 349–384.

12 PALAEONTOLOGY

1

2

3

4

5

6

7

8

9

10

11

12

13

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32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

—— and LI , J.-L. 1983. A new dicynodont from East Africa

and its classification. Palaeontology, 26, 389–406.

CROMPTON, A. W. and HOTTON, N. 1967. Functional

morphology of the masticatory apparatus of two dicynodonts

(Reptilia, Therapsida). Postilla, 109, 1–51.

CROZIER, E. A. 1970. Preliminary report on two Triassic dic-

ynodonts from Zambia. Palaeontologia Africana, 13, 39–45.

CRUICKSHANK, A. R. I. 1967. A new dicynodont genus

from the Manda Formation of Tanzania (Tanganyika). Journal

of Zoology, London, 153, 163–208.

EWER, R. F. 1961. The anatomy of Daptocephalus leoniceps

(Owen). Proceedings of the Zoological Society of London, 136,

375–402.

GOVENDER, R. 2005. Morphological and functional analysis

of the postcranial anatomy of two dicynodont morphotypes

from the Cynognathus Assemblage Zone of South Africa and

their taxonomic implications. Unpublished PhD Thesis, Uni-

versity of the Witwatersrand, Johannesburg, 190 pp.

HANCOX, P. J., SHISHKIN, M. A., RUBIDGE, B. S. and

KITCHING, J. W. 1995. A threefold subdivision of the

Cynognathus Assemblage Zone (Beaufort Group, South Africa)

and its palaeogeographical implications. South African Journal

of Science, 91, 143–144.

JOHNSON, M. R., VAN VUUREN, C. J., HEGENBER-

GER, W. F., KEY , R. and SHOKO, U. 1996. Stratigraphy of

the Karoo Supergroup in southern Africa: an overview. Journal

of African Earth Sciences, 23, 3–15.

KEYSER, A. W. 1973. A new Triassic vertebrate fauna from

South West Africa. Palaeontologia Africana, 16, 1–15.

——1974. Evolutionary trends in Triassic dicynodonts. Palaeont-

ologia Africana, 17, 57–68.

—— and CRUICKSHANK, A. R. I. 1979. The origins and

classification of Triassic dicynodonts. Transactions of the Geo-

logical Society of South Africa, 82, 81–108.

KING, G. M. 1981. The functional anatomy of a Permian

dicynodont. Philosophical Transactions of the Royal Society of

London, Series B, 291, 243–322.

——1988. Anomodontia. In WELLNHOFER, P. (ed.). Hand-

buch der Palaoherpetologie, Teil 17C. Gustav Fischer Verlag,

Stuttgart, 174 pp.

—— 1990. The Dicynodonts: a study in palaeobiology. Chapman

& Hall, New York, NY, 223 pp.

——1993. How many species of Diictodon were there? Annals of

the South African Museum, 102, 303–325.

—— OELOFSEN, B. W. and RUBIDGE, B. S. 1989. The

evolution of the dicynodont feeding system. Zoological Journal

of the Linnaean Society, 96, 185–211.

LUCAS , S. G. 1993. The Shansiodon biochron, Middle Triassic

of Pangea. Albertiana, 11, 40–42.

MAISCH, M. W. 2001. Observations on Karoo and Gondwana ver-

tebrates. Part 2: a new skull-reconstruction of Stahleckeria potens

von Huene, 1935 (Dicynodontia, Middle Triassic) and a recon-

sideration of kannemeyeriiform phylogeny. Neues Jahrbuch fur

Geologie und Palaontologie, Abhandlungen, 220, 127–152.

——2002a. A new basal lystrosaurid dicynodont from the Upper

Permian of South Africa. Palaeontology, 45, 343–359.

—— 2002b. Observations on Karoo and Gondwana vertebrates.

Part 4: The taxonomic status of the Late Permian rhachio-

cephalid Platycyclops crassus Broom, 1948 (Therapsida: Dicyn-

odontia) from the South African Karoo. Neues Jahrbuch fur

Geologie und Palaontologie, Monatshefte, 2002, 362–372.

—— 2003. Lower jaw morphology and jaw adductor muscula-

ture of the giant Permian dicynodont Rhachiocephalus Seeley,

1898 (Therapsida) from the Late Permian of Tanzania. Geolog-

ica et Palaeontologica, 37, 89–106.

MODESTO, S., RUBIDGE, B., VISSER, I. and WEL-

MAN, J. 2003. A new basal dicynodont from the Upper

Permian of South Africa. Palaeontology, 46, 211–223.

OWEN, R. 1859. On the orders of fossil and recent Reptilia

and their distribution in time. Report of the British Associa-

tion for the Advancement of Science, 153–166.

P ICKFORD, M. 1995. Karoo Supergroup palaeontology of

Namibia and brief description of a thecodont from Oming-

onde. Palaeontologia Africana, 32, 51–66.

RENAUT, A. J. 2000. A re-evaluation of the cranial morphol-

ogy and taxonomy of the Triassic dicynodont genus

Kannemeyeria. Unpublished PhD Thesis, University of the

Witwatersrand, Johannesburg, 247 pp.

——DAMIANI , R. J., YATES , A. M. and HANCOX, P. J.

2003. A taxonomic note concerning a dicynodont (Synapsida,

Anomodontia) from the Middle Triassic of East Africa. Pala-

eontologia Africana, 39, 93–94.

—— and HANCOX, P. J. 2001. Cranial description and taxo-

nomic re-evaluation of Kannemeyeria argentinensis (Theraps-

ida: Dicynodontia). Palaeontologia Africana, 37, 81–91.

RUBIDGE, B. S. 1990. Redescription of the cranial morphol-

ogy of Eodicynodon oosthuizeni (Therapsida, Dicynodontia).

Navorsinge van die Nasionale Museum. Bloemfontein, 7, 1–25.

—— and HOPSON, J. A. 1990. A new anomodont therapsid

from South Africa and its bearing on the ancestry of Dicyn-

odontia. South African Journal of Science, 86, 43–45.

————1996. A primitive anomodont therapsid from the base

of the Beaufort Group (Upper Permian) of South Africa. Zoo-

logical Journal of the Linnean Society, 117, 115–139.

SMITH, A. B. 1994. Systematics and the fossil record. Blackwell

Scientific Publications, Oxford, 000 pp.1

SMITH, R. and SWART, R. 2002. Changing fluvial environ-

ments and verterbrate taphonomy in response to climatic dry-

ing in a mid-Triassic rift valley fill: the Omingonde Formation

(Karoo Supergroup) of central Namibia. Palaios, 17, 249–267.

SULLIVAN, C. and REISZ, R. R. 2005. Cranial anatomy and

taxonomy of the Late Permian dicynodont Diictodon. Annals

of Carnegie Museum, 74, 45–75.

SURKOV, M. V. 2000. On the historical biogeography of Mid-

dle Triassic anomodonts. Paleontological Journal, 34, 84–88.

—— and BENTON, M. J. 2004. The basicranium of

dicynodonts (Synapsida) and its use in phylogenetic analysis.

Palaeontology, 47, 619–638.

—— KALANDADZE, N. N. and BENTON, M. J. 2005.

Lystrosaurus georgi, a dicynodont from the Lower Triassic of

Russia. Journal of Vertebrate Paleontology, 25, 402–413.

SWOFFORD, D. L. 1993. PAUP: Phylogenetic Analysis Using

Parsimony, Version 3.1. Illinois Natural History Survey,

Champaign, IL.

TOERIEN, M. J. 1955. Important new Anomodontia. Pala-

eontologia Africana, 3, 62–72.

DAMIANI ET AL . : TRIASSIC ANOMODONT SYNAPSID FROM NAMIBIA 13

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VEGA-DIAS , C., MAISCH, M. W. and SCHULTZ, C. L.

2004. A new phylogenetic analysis of Triassic dicynodonts

(Therapsida) and the systematic position of Jachaleria can-

delariensis from the Upper Triassic of Brazil. Neues Jahrbuch

fur Geologie und Palaontologie, Abhandlungen, 231, 145–166.

—— —— 2004. Postcranial material of Jachaleria candelariensis

Araujo and Gonzaga 1980 (Therapsida, Dicynodontia), Upper

Triassic of Rio Grande do Sul, Brazil. Paleobios, 24, 7–31.

WATSON, D. M. S. 1948. Dicynodon and its allies. Proceedings

of the Zoological Society of London, 188, 823–877.

APPENDIX

Description of characters used in the phylogenetic analysis

1. Snout open to back of skull (0); partly closed-off from rest of

skull owing to posteromedial extension of anterior margin of

orbit (1). After Angielczyk (2001).

2. Dorsomedian ridge of the snout absent (0); present and

restricted to premaxilla (1); present on premaxilla and nasals

(2); present on premaxilla, nasals and frontals (3). A dorso-

median ridge on the snout is defined as a distinctive medial

crest that is orientated anteroposteriorly. We do not consider

anteroposterior doming of the snout to be a dorsomedian

ridge. The presence of well-developed, lateral nasal bosses

may result in the appearance of a dorsomedian ridge. How-

ever, this is an artefact caused by the natural convexity of the

snout and the depressions medial to the paired nasal bosses.

Modified from Maisch (2001).

3. Nasal bosses absent (0); present as single median swelling (1);

present as paired bosses near dorsal ⁄ posterodorsal margin of

external nares (2). Modified from Angielczyk (2001). We do

not consider Pristerodon to possess a median swelling on the

nasals, contra Angielczyk (2001). However, the presence of a

median swelling on the nasals may be related to size, because,

with the exception of Kingoria, all other taxa that appear to

possess this feature are fairly small.

4. Nasal contacts maxilla precluding septomaxilla-lacrimal con-

tact (0); lacrimal contacts septomaxilla, separating nasal from

maxilla (1). Modified from Maisch (2001).

5. Nasal-lacrimal contact absent (0); present (1).

6. Length of internasal suture equal to or greater than half the

length of the nasal (0); less than half the length of the nasal

(1). After Vega-Dias et al. (2004).

7. Transverse ridge across snout at level of prefrontals absent

(0); present (1). After Angielczyk (2001).

8. Antorbital sulcus absent (0); present (1). This refers to a

depression at the anterior margin of the orbit, formed by

ridges occurring on the prefrontal above and the lacrimal

and ⁄ or the jugal below the depression. However, both ridges

do not necessarily have to occur to form the sulcus. Modified

from Maisch (2001).

9. Interorbital width at its narrowest point less than anteropos-

terior diameter of orbit (0); equal to or greater than antero-

posterior diameter of orbit (1). This character is related to

the extent of exposure of the orbits in dorsal view: taxa with

broadly exposed orbits possess narrow interorbital regions,

and vice versa. With few exceptions, the interorbital width at

its narrowest point usually occurs where the postorbitals con-

tribute to the dorsal rim of the orbit. The anteroposterior

diameter of the orbit was chosen as a reference point because

it is usually subject to little distortion.

10. Postfrontal present (0); absent (1). After Maisch (2001).

11. Posterior projections of frontals terminate before or level

with anterior margin of pineal foramen (0); lateral to the

pineal foramen (1); posterior to pineal foramen (2).

Although state 1 in our analysis could be subdivided into

two states, we treat it as a single state because the presence

of a preparietal will preclude contact between the frontals

and the anterior margin of the pineal foramen.

12. Preparietal present (0); absent (1). After Maisch (2001).

13. Prepineal boss absent (0); present (1). This character refers

to whether or not a boss (either low or distinctive) is pres-

ent anterior to the pineal foramen. The position of this boss

may be on the preparietal or the frontals.

14. Pineal foramen flush (or nearly so) with dorsal surface of

skull (0); sunken below dorsal surface of skull (1); sur-

rounded by a boss (2). Modified from Angielczyk (2001).

15. Intertemporal bar in same plane as dorsal skull roof (0); at

angle to dorsal skull roof (1). In some taxa, there is a

depression between the dorsal skull roof and the inter-

temporal bar. We do not consider this to represent an angu-

lation of the intertemporal bar because it remains in the

same plane as the doral skull roof. In Kannemeyeria and

Ischigualastia the angulation between the frontal plate and

the intertemporal bar is very pronounced. However, we do

not distinguish between different degrees of angulation of

the intertemporal bar. Modified from Maisch (2001).

16. Dorsal exposure of parietals broad and low (0); narrow and

low (1); narrow and crested (2); broad and crested (3). This

character refers to the dorsal exposure of the parietals on

the intertemporal bar. The term ‘low’ refers to the exposure

of the parietals within a central groove or depression caused

by overlap of the postorbitals. The condition where there is

no dorsal exposure of the parietals owing to complete over-

lap by the postorbitals is coded as character state 1. The

term ‘crested’ refers to dorsal exposure of the parietals

above, or at the same level as, the postorbitals. Modified

from Angielczyk (2001).

17. Postorbital contacts squamosal posteriorly (0); postorbital

separated from squamosal by lateral exposure of parietals

(1). After Maisch (2001).

18. Postorbital with distinct anterior contribution to suborbital

bar present (0); absent (1). This character refers to the pres-

ence of an anteriorly directed ‘footplate’ of the postorbital

that contributes to the suborbital bar.

19. Contact between squamosal and postorbital in suborbital

bar (0); squamosal separated from postorbital by jugal (1).

20. Zygomatic process of squamosal does not contact maxilla

(0); contacts maxilla (1). After Angielczyk (2001).

21. Squamosal without lateral recess (0); with lateral recess (1).

The lateral recess on the squamosal is the origin of the lat-

eral branch of the adductor mandibulae externus. After

Angielczyk (2001).

14 PALAEONTOLOGY

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22. Interparietal excluded from skull roof (0); restricted to pos-

terior skull margin only (1); forms a significant part of the

intertemporal bar (2). Modified from Maisch (2001).

23. Tusks absent (0); present (1). Modified from Maisch (2001).

The polarity of this character is reversed from Maisch

(2001) because tusks are absent in all basal anomodonts.

24. Caniniform process absent (0); present (1); present with a

notch anterior to it (2). After Angielczyk (2001).

25. Distinct lateral caniniform buttress absent (0); present (1);

present with posteroventral furrow (2). This character refers

to lateral expansion of the caniniform process into a distinct

ridge that may or may not be seen in dorsal view. We con-

sider the degree of lateral exposure in dorsal view to be sub-

ject to distortion. Modified from Maisch (2001).

26. Keel-like extension of palatal rim posterior to caniniform

process absent (0); present (1). After Angielczyk (2001).

27. Postcaniniform crest absent (0); present (1). In Kannemeye-

ria and Dolichuranus, a distinct furrow is present on the

posteroventral surface of the caniniform process, which

appears to be the result of the extreme lateral development

of the caniniform buttress. Consequently, a ridge is present

along the medial margin of the furrow, but this is not a

postcaniniform crest. After Angielczyk (2001).

28. Premaxillary teeth present and located laterally (0); present

but located medially (1); absent (2). After Angielczyk

(2001).

29. Upper postcanine teeth located near lateral margins of max-

illa (0); located medially but with posterior teeth approach-

ing lateral margins of maxilla (1); located medially and a

consistent distance away from lateral margins of maxilla (2);

absent (3). After Angielczyk (2001).

30. Shelf-like area lateral to upper postcanine teeth absent (0);

present (1). After Angielczyk (2001).

31. Premaxillae unfused (0); fused (1). After Angielczyk (2001).

32. Paired anterior palatal ridges of premaxilla absent (0); pres-

ent but converge posteriorly (1); present but do not con-

verge (2). After Angielczyk (2001).

33. Posterior median palatal ridge of premaxilla absent (0);

present but with flattened and expanded anterior area (1);

present without flattened and expanded anterior area (2).

After Angielczyk (2001).

34. Palatal surface of premaxilla lateral to median palatal ridge

with well-defined depressions with curved sides (0); with

groove-like depressions that have straight sides and rounded

anterior ends (1); relatively flat with poorly defined or no

depressions present (2). After Angielczyk (2001)

35. Premaxilla contacts anterior margin of choana: present (0);

absent (1).

36. Palatine separated from premaxilla by maxilla (0); contact

between premaxilla and palatines (1). Modified from Angi-

elczyk (2001).

37. Secondary palate absent (0); present with choana extending

anteriorly into secondary palate (1); present but without

choana extending anteriorly into secondary palate (2). Char-

acter state 1 refers to deep grooves that are extensions of the

choana anteriorly. These extensions run between the vomers

and the palatine pads, but they are only coded as present if

they extend beyond the palatine pads and into the secondary

palate. This is because a similar condition is created by the

medial expansion of the palatine pads into the choana.

38. Vomers unfused (0); fused (1). After Angielczyk (2001).

39. Mid-ventral plate of vomers with expanded area posterior to

junction with premaxilla (0); without expanded area poster-

ior to junction with premaxilla (1). After Angielczyk (2001).

40. Mid-ventral plate of vomers in palatal view wide (0); narrow

and blade-like (1). After Angielczyk (2001).

41. Interpterygoid vacuity, comprising pterygoids anteriorly,

small and positioned posteriorly within choana (0); large,

comprising vomers anteriorly and contacts palatine pads (1);

large, but with no contact with palatine pads (2); small and

positioned posteriorly within choana (3); small and posi-

tioned within the pterygoid corpus (4). The morphology of

the interpterygoid vacuity in basal anomodonts differs from

that in dicynodonts. In the former, the interpterygoid vacu-

ity is completely enclosed by the pterygoids, whereas in the

latter, the interpterygoid vacuity is bounded anteriorly by

the vomers. A further state has been added in which the in-

terpterygoid vacuity is situated posterior to the choana and

within the pterygoid corpus. Modified from Angielczyk

(2001).

42. Palatal exposure of palatines without evidence of keratinized

covering (0); with fine pitting or rounded bulbous surface

texture that may have had keratinized covering (1); with dis-

tinct pitting and rugose surface texture suggestive of kerati-

nized covering (2). Modified from Angielczyk (2001).

43. Foramen on palatal exposure of palatines absent (0); present

(1). After Angielczyk (2001).

44. Lateral palatal foramen absent (0); present at level of ante-

rior expanded palatal exposure of palatines (1); present pos-

terior and dorsal to level of anterior expanded palatal

exposure of palatines (2). After Angielczyk (2001).

45. Labial fossa absent (0); present (1). After Angielczyk (2001).

46. Ectopterygoid present (0); absent (1). An ectopterygoid is

present in Permian but not Triassic dicynodonts (Keyser

and Cruickshank 1979; Maisch 2001). After Maisch (2002a).

47. On lateral surface of pterygoid girder, pterygoid process of

maxilla absent (0); present (1). This character refers to a

process of the maxilla that extends posteriorly onto the lat-

eral surface of the pterygoid girder, often occupying the

position of the absent ectopterygoid.

48. Transverse flange of anterior pterygoid process well devel-

oped (0); reduced (1). After Angielczyk (2001).

49. Quadrate flange of squamosal in posterior view with rela-

tively straight contour and no dorsolateral notch (0); flared

laterally, but not beyond zygomatic arch, forming a shallow

dorsolateral notch (1); flared laterally beyond zygomatic

arch, forming a deep dorsolateral notch (2); flared laterally

but without forming dorsolateral notch (3). Modified from

Angielczyk (2001) and Maisch (2001).

50. Occipital width less than maximum skull length (0); equal to

or greater than maximum skull length (1). After Maisch

(2001).

51. Teeth present on dorsal surface of dentaries (0); present on

medial shelf (1); absent (2). After Angielczyk (2001).

52. Posterior dentary sulcus absent (0); present (1). After Angi-

elczyk (2001).

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53. Lateral dentary shelf absent (0); present but small (1); pres-

ent as boss-like swelling located near ventral margin of jaw

ramus (2); present and well developed (3). After Angielczyk

(2001).

54. Dentary table absent (0); present as small rounded expan-

sion of dorsal surface of dentary located near symphysis (1);

present as elongate grooved surface on dorsal surface of den-

tary bounded laterally by low ridge and medially by tall,

thin, dorsally convex blade (2); bounded by low ridges (3).

After Angielczyk (2001).

55. Symphyseal region of lower jaw smoothly rounded and bear-

ing teeth (0); with upturned margin that is raised above

dorsal surface of jaw rami and has scooped-out depression

on its posterior surface (1); drawn into sharp, spiked beak

(2); shovel-shaped with rounded ⁄ squared-off edge and weak

depression on its posterior surface (3); with wedge-shaped

margin that does not extend much above dorsal surface of

jaw rami and groove-like depression on its posterior surface

(4). After Angielczyk (2001).

56. Coronoid eminence on lower jaw present (0); absent (1).

The coronoid bone is lost in all anomodonts (King 1988); it

is replaced by a dorsal swelling of the lower jaw that has

been termed the coronoid eminence (Cox 1998).

Character-taxon matrix

Character states are denoted by the following symbols: 0, primitive; 1–4, derived; ?, state unknown because of inadequate preservation;

N, character inapplicable; P, polymorphic (character 3: states 0 and 2 in Lystrosaurus; character 13: states 0 and 1 in Aulacephalodon,

Dicynodon and Oudenodon; character 23: states 0 and 1 in Diictodon).

1

1234567890

1111111112

1234567890

2222222223

1234567890

3333333334

1234567890

4444444445

1234567890

555555

123456

Aulacephalodon 0121101111 10P2000111 111110023N 1222011110 2201100110 211310

Cistecephalus 1010100011 0100000101 110101023N 1021012111 2111000101 213030

Daptocephalus 000010011? 0000010101 101110023N 1222011111 3201100110 211310

Dicynodon 0020100010 10P0010101 101110023N 1222011111 3201100110 211310

Diictodon 0010000000 0000010101 10P200023N 1110001111 2101000110 201210

Dinanomodon 020000001? 1001110001 101110023N 1222001111 2101101120 ??????

Dolichuranus 0020110111 2001020001 111120023N 1222001101 4201100120 200311

Endothiodon 0220000010 00020301?0 1?00000121 1022101100 31020?0120 112020

Eodicynodon 0000000000 000000?100 1011000200 0010001000 2101000010 003130

Ischigualastia 0100110011 2011121101 120100023N 122201210? 3201110130 211341

Kannemeyeria 0300000011 2001110001 111120023N 1222012111 3201111120 200341

Kingoria 0011100001 0010020100 101101023N 102?001110 2001000120 20?03?

Lystrosaurus 00P1001110 0000000001 101110023N 1222001111 3201111121 211341

Myosaurus 100??00001 0000000000 100101023N 1021012111 2011000100 203030

Oudenodon 0121100000 10P0010111 110110123N 1222011110 1201000110 211310

Pelanomodon 0021111001 1000000111 110100123N 1222012111 1201100110 ??????

Pristerodon 000??00000 00000?00?1 1111000210 1112011100 2102000110 113110

Rhachiocephalus 0020000011 1002120111 100100123N 122201?111 2201000110 211310

Robertia 001?100000 ?0000001?1 1112000210 1110001100 2101000110 101210

‘Shansiodon’ 0001100111 0001021001 111100023N 1222002110 3202111120 200210

Stahleckeria 0120110011 1101100101 120100023N 12220121?0 420?11?121 211341

Tetragonias 0220000111 0000111001 101100023N 1222002100 320?111121 211210

Vinceria 0201100111 0001110001 111110023N 1222002111 3201111120 201210

Patranomodon 0000000000 0000000000 0000000000 0000000000 0000000000 000000

List of comparative material

The character-taxon matrix was coded based on our examina-

tion of the specimens listed below, and (to a lesser extent) on

the literature. Additional information was obtained from Cluver

and Hotton (1981), Cluver and King (1983), and King (1988).

Aulacephalodon sp. BP ⁄ 1 ⁄ 766, 806.

Aulacephalodon baini: BP ⁄ 1 ⁄ 634 (holotype of A. ‘vanderhorsti’).

Cistecephalus microrhinus: BP ⁄ 1 ⁄ 580.

Dicynodon daptocephaloides: BP ⁄ 1 ⁄ 555 (holotype); Toerien

(1955).

Dicynodon leontocephalus: BP ⁄ 1 ⁄ 2880, 4026.

Daptocephalus leoniceps: BP ⁄ 1 ⁄ 2188, 5287; Ewer (1961).

Diictodon feliceps: BP ⁄ 1 ⁄ 316, 2112; Sullivan and Reisz (2005).

Dinanomodon rubidgei: RC 9 (holotype).

Endothiodon uniseries: BP ⁄ 1 ⁄ 1659.

Eodicynodon oosthuizeni: NM QR2902, 2904–2906, 2909, 2911,

2912, 2978, 2990, 2991, 2996, 3001, 3002, SAM-PK-11879; Ru-

bidge (1990).

Ischigualastia jenseni: MCZ 18Æ055 (holotype), MCZ 3118–3120;

Cox (1965).

Kannemeyeria simocephalus: BP ⁄ 1 ⁄ 1127, 1168, 4523; Renaut

(2000).

16 PALAEONTOLOGY

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Lystrosaurus murrayi: BP ⁄ 1 ⁄ , 1754, 4798; Cluver (1971).

Kingoria sp. BP ⁄ 1 ⁄ 1562, 3858.

Myosaurus gracilis: BP ⁄ 1 ⁄ 2690, 2701b.

Oudenodon baini: BP ⁄ 1 ⁄ 230, 730, 786.

Patranomodon nyaphulii: NM QR3000 (holotype); Rubidge and

Hopson (1990, 1996).

Pelanomodon halli: BP ⁄ 1 ⁄ 792 (holotype).

Pristerodon sp. BP ⁄ 1 ⁄ 2642.

Rhachiocephalus sp. BP ⁄ 1 ⁄ 1512.

Robertia broomiana: SAM-PK-11761 (holotype).

‘Shansiodon’ sp. BP ⁄ 1 ⁄ 5532.

Stahleckeria potens: Cruickshank (1967); Maisch (2001).

Tetragonias njalilus: UMZC R2840d; Cruickshank (1967).

Vinceria andina: PVL 3831 (holotype); Renaut and Hancox

(2001).

DAMIANI ET AL . : TRIASSIC ANOMODONT SYNAPSID FROM NAMIBIA 17

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