Article: Basal Turonian Ammonites from west Texas
A rich ammonite fauna is described from the basal Turonian Pseudaspidoceras flexuosum Zone of west Texas. Taxa present include typically Boreal, Tethyan, and US Western Interior species and widely occurring forms of the bivalve Mytiloides. This co-occurrence of key species from different faunal realms and provinces provides a basis for correlation of the base of the Turonian stage. Species present are the ammonites Quitmaniceras reaseri Powell, 1963, Kamerunoceras calvertense Powell, 1963, Pseudaspidoceras flexuosum Powell, 1963, Mammitespowelli sp. nov., Vascocerasproprium Reyment, 1954, Fagesia catinus (Mantell, 1822), Neoptychites sp., Wrightoceras munieri (Pervinquiere, 1907), Thomasites adkinsi (Kummel and Decker, 1954), Allocrioceras dentonense Moreman, 1942, A. larvatum (Conrad, 1855), Sciponoceras sp., and Worthoceras cf. vermiculus (Shumard, 1860). The Mytiloides present is referred to M. columbianus (Heinz, 1935), the M. opalensis of authors (non Bose, 1923).