Early Triassic gastropods from the Sinbad member of the Moenkopi Formation, San Rafael Swell, Utah. American Museum novitates ; no. 2864

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New York, N.Y. : American Museum of Natural History
"The Sinbad gastropod fauna is important because it is the most diverse early Triassic fauna known, with 16 genera and 26 species, 22 of which are new. It is not a typical offshore marine fauna like those found in the post-Scythian. It consists of enormous numbers of embryonic shells and small-size species in coquinal limestones. Pelecypods are equally abundant but are poorly preserved and show even less diversity. Ammonoids, important as index fossils, are present but rare. Sponges, echinoderms, algae, and conodonts are also represented by scattered individuals. All other rocks of Scythian age have yielded just a few species representing conservative, long ranging genera such as Worthenia, Coelostylina, Naticopsis, or Omphaloptychia also found in the Sinbad. In addition, the Sinbad fauna contains the trochids Boutillieria, Natiria, and Chartronella; the neritids Vernelia and Neritaria; the loxonematids Zygopleura, Kittliconcha, and Anoptychia; the cerithid Promathilda; the subulitid Strobeus, and the opisthobranch Cylindrobullina. Sedimentary evidence suggests that the Sinbad fauna was distributed in a subtidal lagoonal environment in an arid climate"--P. [1].
33 p. : ill., map ; 26 cm.
Includes bibliographical references (p. 32-33).