Litoceras Hyatt 1884
Genus Litoceras Hyatt, 1884 Type species Nautilus versutus Billings, 1865 (part), from Gargamelle Cove, Pointe Riche Peninsula, western Newfoundland, Canada (lower Table Head Formation, Darriwilian, see Stouge 1984); by original designation. Diagnosis Thickly subdiscoidal to subglobular conchs with...
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Zenodo
2021
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Online Access: | https://dx.doi.org/10.5281/zenodo.5793592 https://zenodo.org/record/5793592 |
Summary: | Genus Litoceras Hyatt, 1884 Type species Nautilus versutus Billings, 1865 (part), from Gargamelle Cove, Pointe Riche Peninsula, western Newfoundland, Canada (lower Table Head Formation, Darriwilian, see Stouge 1984); by original designation. Diagnosis Thickly subdiscoidal to subglobular conchs with rapidly enlarging, depressed whorls; mature body chamber may become evolute; ornamented with growth lines, which slope apicad from the umbilical shoulder to the hyponomic sinus, growth lines may become fasciculate, and costae may develop which are not, however, prominent, and are not ordinarily evident on the internal mold; straight transverse sutures or faint ventral saddles may develop; siphuncle initially ventral, dorsal by the completion of the second volution (adopted from Flower 1968: 44). Remarks The type specimens (originally described as Nautilus versutus , referred to L . whiteavesi Hyatt, 1894 by Hyatt 1894: 475) have been listed as collected from the St. George and/or Table Head Group of western Newfoundland in Ulrich et al. (1942: 78). However, Flower (1979: 223) stated “after extensive collecting of coiled cephalopods, both from the St. George Group and in the Table Head limestone, it is clear that there is no true Litoceras in the St. George Group nor in any known late Canadian faunas. Specimens very close to L . versutum have been obtained in the Table Head limestone, from which I have obtained at least 35 large coiled cephalopods; all but one belong to Litoceras ”. : Published as part of Kröger, Björn & Pohle, Alexander, 2021, Early-Middle Ordovician cephalopods from Ny Friesland, Spitsbergen - a pelagic fauna with Laurentian affinities, pp. 1-102 in European Journal of Taxonomy 783 (1) on pages 66-67, DOI: 10.5852/ejt.2021.783.1601, http://zenodo.org/record/5793422 : {"references": ["Stouge S. S. 1984. Conodonts of the Middle Ordovician Table Head Formation, western Newfoundland. Fossil and Strata 16: 1 - 145.", "Flower R. H. 1968. Part I. The first great expansion of the actinoceroids. Part II. Some additional Whiterock cephalopods. New Mexico Bureau of Mines and Mineral Resources, Memoir 19: 1 - 120.", "Hyatt A. 1894. Phylogeny of an acquired characteristic. Proceedings of the American Philosophical Society 32: 349 - 647. https: // doi. org / 10.5962 / bhl. title. 59826", "Ulrich E. O., Foerste A. F., Miller A. K. & Furnish W. M. 1942. Ozarkian and Canadian cephalopods: Part I: Nautilicones. Geological Society of America Special Papers 37: 1 - 157. https: // doi. org / 10.1130 / SPE 37 - p 1", "Flower R. H. 1979. St. George and Table Head cephalopod zonation in western Newfoundland. Papers of the Geological Survey of Canada 78: 217 - 224. https: // doi. org / 10.4095 / 103891"]} |
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