Albian Caprinid rudists from Texas re-evaluated

Abstract

Of the 33 caprinid rudist taxa reported from Albian strata in North America, only eighteen can be recognized unequivocally because many of the earlier named species were based on incomplete, altered, and poorly described specimens that do not meet rigorous criteria of modern rudist taxonomy. New data on five older taxa, “Caprina” crassifibra Roemer, 1849; “Caprina” guadalupe Roemer, 1849; “Caprina” occidentalis Conrad, 1855; “Caprina” planata Conrad, 1855, and “Icthyosarcolites” anguis Roemer, 1888, show that these species cannot be compared to current rudist taxa nor identified with certainty and therefore they should not be used in biostratigraphic, paleoecologic, or biogeographic studies. Four other taxa are poorly known and should not be used until the types or new material can be studied. Six taxa are considered here to be junior synonyms. New material collected from Upper Albian strata in West Texas, the type area of Conrad's taxa, can be identified as Kimbleia albrittoni Perkins, 1961; Kimbleia capacis Coogan, 1973; Texicaprina vivari Palmer, 1928; and Mexicaprina cornuta Coogan, 1973. The ranges of these four taxa define three zones within Upper Albian carbonates in central and west Texas.