• Source: Aspidoceras
  • Aspidoceras is an extinct ammonoid cephalopod genus belonging to the family Aspidoceratidae.


    Taxonomy


    Aspidoceras, named by Zittel, 1868, is the type genus for the persphictacian family Aspidoceratidae and subfamily Aspidoceratinae in which it is included. It is considered related to genera like Chinamecaceras, Cubaspidoceras, Euaspidoceras, Extranodites, Intranodites, Neaspidoceras, Oligopsychopsis, Orthaspidoceras, Schaireria and Simaspidoceras.


    Selected species


    Aspidoceras argobbae Dacque 1905
    Aspidoceras catalaunicum Loriol 1872
    Aspidoceras somalicum Dacque 1905
    Aspidoceras supraspinosum Dacque 1905


    Fossil record


    Aspidoceras mainly lived during the Late Jurassic (Oxfordian) until Cretaceous (Berriasian), with a fairly broad distribution. Fossils have been found in Italy, Chile, Spain, Algeria, Antarctica, Argentina, Ethiopia, France, Germany, Hungary, India, Iran, Madagascar, Portugal, Romania, Russia, Somalia, Switzerland, the United Kingdom, United States and Canada.


    Description


    Aspidoceras has an evolute shell with quadrate-rounded or depressed whorls that have two rows of tubercles, the outer near the middle of the whorl sides. The outer row soon fades in many species. Some species are also ribbed. The venter, or outer rim, is generally wide and broadly arched. Aspidoceras was predated by Euaspidoceras, possibly its ancestor.


    See also


    List of ammonite genera


    References




    Further reading


    Arkell, et al.,1957. Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology, Part L (Ammonoidea). Geol Soc of America and Univ Kansas Press. p. L338-339.

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