C.H.C. BRUNTON 
Fig. 25 Zalvera sp. from early Upper Moscovian rocks north of Bran- 
cosera, Palencia, Spain. 25a,b, apical and iateral views of the speci- 
men (<1) showing an ‘umbonal’ region (arrowed). 25e, an 
enlargement (<3) of 25b showing pseudopunctate shell (arrowed) 
and the layered nature of the valve, each with thin sediment between. 
National Museum of Natural History, Leiden, WAG 77. 
Winkler Prins (personal communication, September 1993) as 
Proteguliferina sp. from Austria are not Za/vera, but are more 
like an early form of the Permian teguliferinid Acritosia. 
The two Moscovian specimens from northern Spain resemble 
Z. sibaica closely, but appear to differ in having well flattened 
apices, suggesting closer attachment to the substrate than seen in 
the specimens from the Urals. Both specimens show signs of the 
subparallel internal ridges, the apical internal 
microtuberculation and both have comparable external irregular 
rugae. These similarities between the Spanish and Russian 
specimens reinforce the concept of widespread marine faunas in 
Eurasia during Upper Carboniferous times. 
Present evidence, therefore, indicates two almost 
contemporaneous stocks in the early to mid Upper 
Carboniferous, one in North America which evolved into the 
Richthofeniidae, the other in Russia which, although considered _ 
as belonging in the Richthofenioidea, was an _ early 
‘experimental’ stock which lost its spines early in ontogeny and 
lived on relatively soft substrates, unlike the American forms : 
Figs 22-24 Zalvera sibaica gen. et sp. nov. from late Bashkirian to 
early Moscovian rocks in the southern Urals, Russia. 22, a cut and 
lightly etched section through a ventral valve just distal to the inter- 
nal thickening against which the dorsal valve rested. Apex to the top 
right, exterior to the left. Irregularities in the laminae are oblique sec- 
tions through pseudopunctae, apparently with taleolae (arrows), 
BD9669a, 160. 23, same section, closer to the apex, x1200. 24, a 
fracture flake of shell from a thickened area of a dorsal valve. Signs 
of original laths can be seen centrally, BD9670, x5000. 
