PROTORICHTHOFENIOID BRACHIOPOD FROM URALS 
2a 2b 
5mm 
Fig. 21 Reconstruction of the apical area of Za/vera in median longi- 
tudinal section (1a), between the subparallel ridges, and an apical 
view of the ventral valve at the arrow position (1b). In 2a the section 
cuts one of the subparallel ridges in which the articulatory groove is 
situated (2b). Ventral valve black; dorsal valve stippled. 
(BD9671) (Fig. 10). Also, the species seem to be of comparable 
size and both have similar concentric ornamentation. Dr 
Lazarev has inspected the Tschernyschev specimen and confirms 
the similarity. 
Another similar-looking species was first described by 
Likharev in 1931 as Teguliferina? (Chaoella) caucasica and 
again in 1932 as Keserlingina caucasica. It came from Permian 
rocks in the Caucasus, originally described as P,,, but now 
thought to be of Kazanian, early Upper Permian age. Likharev 
also recorded related specimens from the Sim river in the 
southern Urals. Likharev (1932) gives a measure of 9mm for the 
maximum width, so his specimens are about half the size of the 
new material. Otherwise the illustrations closely resemble the 
Carboniferous specimens and one figure (1932, pl. 2, fig. 9b) 
seems to show similar subparallel marks near the apex. In 
describing caucasica Likharev briefly referred to uralica, but 
other than discussing the apparent small ventral valve at the 
apex he wrote little to differentiate between the two species. 
Thus, somewhat similar specimens to Z. sibaica occurred in 
the Urals at Bashkirian to Moscovian boundary times and again 
in the Permian. Neither Tschernyschev’s JT. uralica nor 
Likharev’s K. caucasica belong in Teguliferina or Keyserlingina, 
the latter belonging with the Lyttonioidea on account of its 
lobate interiors. Teguliferina and Proteguliferina belong in the 
Richthofenioidea and are thus more closely related to the new 
material than is Keyserlingina. For instance, Proteguliferina 
displays a weakly concave dorsal valve within a gently convex 
ventral valve which does not reach the internal margins of the 
spinose ventral valve. Its ventral marginal epithelium may, 
therefore, have been exposed. 
Girty (1908) described two species, Tegulifera armata and T. 
kansasensis, from rocks of late Missourian (mid Kasimovian) 
57 
age, from localities in Illinois and Kansas respectively. These 
species differ in important characters from the new Urals 
specimens described here. The American specimens are less 
deeply conical, less rugose, are radially ornamented, and are 
attached by cementation and external spines, as well as having 
internal ventral spines. These species were placed by Muir-Wood 
& Cooper (1960) into Planispina Stehli, a genus assigned to the 
Teguliferininae. The radial ribbing and possible spinose 
exteriors of two specimens in the Urals collection (Fig. 8) 
resemble P. armata (Girty, 1908, pl. 20, fig. 10). 
Sutherland (1989) reported another species, well preserved as 
silicified specimens, from early Upper Carboniferous 
(Morrowan [= Bashkirian]) rocks in Oklahoma, USA. This 
material as yet remains un-named, but is probably closely related 
to Teguliferina, with somewhat similar dorsal valve interiors and 
similar external rhizoid fixing spines. These Morrowan 
specimens, therefore, appear to be the earliest known true 
teguliferinids, and are the earliest known Richthofenioidea. 
The material from the Urals is of similar age to that described 
by Sutherland (1989) but is very different in character, 
resembling more closely the specimens described by 
Tschernyschev (1902) and Likharev (1931). The brachiopod 
relationship of the new Urals material is no longer in doubt and 
the general form of the shell is highly indicative of a 
richthofenioid relationship. However, other than in the Permian 
genus Collumatus Cooper & Grant, 1969, from Texas, the 
richthofenioids have external spines to aid the fixing of 
specimens to hard substrates, commonly within reef 
environments, while Z. sibaica has no such spines. Apart from 
this difference, the general architecture of the shell fits with that 
of richthofenioids; a conical ventral valve with a dorsal valve 
recessed below its margins, the two valves articulating, not by 
true ventral teeth and dorsal sockets, but by dorsal 
protuberances fitting into ventral cavities. In detail the Urals 
specimens differ from the general richthofenioid pattern: they 
lack external spines, other than perhaps at the earliest stages in 
ontogeny when ventral valves show signs of fine spines for about 
5mm of growth; the body cavity is shallow, with the dorsal valve 
deeply recessed below the ventral margin; the dorsal valve has 
internal structures producing relatively thick shelly ridges, the 
brachial impressions and wide median ridge; the dorsal valve has 
short, geniculated, thin-shelled margins extending a short 
distance up the ventral valve interior; the ventral valve interior 
has a simple posteromedian structure of subparallel plates 
acting as supports for the dorsal valve; the ventral valve cone 
interior has sparcely distributed blunt, well rounded, endospines 
protruding into the space above the dorsal valve exterior; there is 
no indication of any complete protection for the opening to the 
subconical valve margins, as in most true richthofenioids. 
In a biostratigraphical description of regions in Cantabria, 
northern Spain, Sanchez de Posada et al. (1993) listed 
‘Proteguliferina? n. sp. from “Kasimovian’ rocks. Dr C. F. 
Winkler Prins has kindly lent me the two specimens from which 
this reference was made, which he now dates as Moscovian, 
possibly Podolsky age. They do appear to be congeneric with the 
new Urals specimens. Specimens (also seen) determined by 
Figs 17-20 Zalvera sibaica gen. et sp. nov. from late Bashkirian to early Moscovian rocks in the southern Urals, Russia. 17, part and counterpart of 
an incomplete dorsal valve showing probable brachial impressions and the median ridge. The valve margins curve away into the rock in 17a, 
BD9659, x4. 18, scanning electron micrograph showing the finely endospinose surface within the dorsal valve brachial impression, BD9659a, x60. 
19, a rather elongate, deformed and partly exfoliated dorsal valve interior; posterior is to the top, showing the transverse ridge (exfoliated and 
arrowed), interpreted as the dorsal articulation structure, and one brachial ridge, on the right, BD9670, x10. 20, holotype viewed apically and 
‘anteriorly’ (1.5) and obliquely apically (x5) showing the positions of the subparallel ridges ‘posteriorly’. BD9653. 
