Rousseauspira: new gastropod operculum from the Ordovician of Alaska and California

Abstract

Rousseauspira teicherti, a new genus and species of an unusual, untwisted, horn-shaped gastropod operculum from shallow-subtidal limestones of the Upper Ordovician of Alaska and the Middle Ordovician of California, is described and compared to two other Ordovician opercula,CeratopeaUlrich, 1911, andTeiichispiraYochelson and Jones, 1968. The shell to which the operculum belonged is not yet known.

Bedrock geologic map of the Seward Peninsula, Alaska, and accompanying conodont data

“…fossil report, 1974;Till and Dumoulin, 1994). DSl has also yielded corals thought to be of probable Middle or Late Devonian age (Oliver and others, 1975); the age of this collection was later revised to late Silurian (late Ludlow)-early Late Devonian (Frasnian), probably late Silurian to Early Devonian, by A. Pedder (Dumoulin and Harris, 1994;Till and Dumoulin, 1994 Harris, 1994), corals (Oliver and others, 1975; R.J. Elias in Blodgett and others, 2002, p. 283), trilobites (Ormiston, 1978;Ormiston and Ross, 1979), and brachiopods, cephalopods, gastropods, ostracodes, pelecypods, and stromatoporoids (Sainsbury, 1969a;Sainsbury and others, 1971;Rohr, 1979Rohr, , 1988Potter, 1984;Rohr and Potter, 1987;Rohr and others, 2003). Rugose corals (Bighornia) indicate a possibly Richmondian age (Dumoulin and Harris, 1994).…”

New Discovery of Oligocene Gastropod Opercula from the Yehucheng Formation in Northwestern China

“…Gastropod opercula have a worldwide distribution and have been found in, for example, Europe, America, Africa, and Asia since the Paleozoic. The earliest opercula fossils were recovered from the late Early Ordovician as well as the middle and late Ordovician (Yochelson and Barnett, 1972;Yochelson, 1975Yochelson, , 1986Potter, 1987, Rohr andYochelson, 1999). In China, gastropod opercula fossils are abundant in Mesozoic and Cenozoic continental strata, and their ages mainly range from the Jurassic to the Quaternary.…”