FISH ASSEMBLAGE FROM THE LATE PENNSYLVANIAN OF THE ROBLEDO MOUNTAINS, NEW MEXICO

A very diverse and rich assemblage of fossil fishes has been found in the Upper Pennsylvanian (Missourian) interval of the Horquilla Formation in the Robledo Mountains of southern New Mexico, USA. The chondrichthyan remains are represented by isolated teeth of the symmoriiform Denaea cf. D. williamsi Ginter and Hansen, and Stethacanthus sp., buccopharyngeal denticles of symmoriiforms; teeth of the xenacanthimorpha Bransonella nebraskensis Johnson, jalodontid Adamantina foliacea Ivanov, and ctenacanthiforms Glikmanius cf. G. occidentalis (Leidy) and Heslerodus sp.; euselachian teeth of Protacrodus sp. and Sphenacanthus sp.; teeth of the anachronistid neoselachian Cooleyella amazonensis Duffin, Richter and Neis, and C. cf. C. fordi (Duffin & Ward); eugeneodontiform teeth resembling Agassizodus and Campodus; fragments of orodontiform, helodontiform and petalodontiform teeth; and scales of various types such as ctenacanthid, orodontid and euselachian. Rare acanthodian scales of Acanthodes sp., different actinopterygian teeth and elonichthyid scales occur also in this assemblage. Most of these chondrichthyan taxa are widely distributed in the Carboniferous and Permian. Cooleyella fordi was recorded in the Visean-Gzhelian interval, the first appearance of C. amazonensis was reported from the Bashkirian and this species also occurs in the Middle Permian. But, Denaea williamsi is known from the Visean to Moscovian. Thus, the comparison of ranges for some taxa shows the possible age of this assemblage as Bashkirian-Moscovian.