Small shelly fossils from the basal Emigrant Formation (Cambrian, uppermost Dyeran Stage) of Split Mountain, Nevada

A latest Early Cambrian fauna of helcionelloid molluscs and small shelly fossils from the basal Emigrant Formation of Nevada is described. The fauna is the first of its kind to be described from trilobite-bearing strata in the Great Basin and is well preserved, but of limited diversity. At the specific level the assemblage is largely endemic, but it contains several genera with global distribution in the Lower and Middle Cambrian. Costipelagiella nevadense n.sp. in the fauna is the oldest representative of the widespread, but little known genus Costipelagiella Horný, 1964. Two additional new taxa are described: Anabarella chelata n.sp. and Parkula esmeraldina n.sp.

[1]  J. A.,et al.  INARTICULATE BRACHIOPODS OF THE LOWER AND MIDDLE CAMBRIAN PIOCHE SHALE OF THE PIOCHE DISTRICT , NEVADA ' , 2008 .

[2]  G. Freeman,et al.  Origin of planktotrophy—evidence from early molluscs: a response to Nützel et al. (2006) , 2007, Evolution & development.

[3]  L. Holmer,et al.  The Lower Cambrian brachiopod Kyrshabaktella and associated shelly fossils from the Harkless Formation, southern Nevada , 2006 .

[4]  C. Skovsted.  SMALL SHELLY FAUNA FROM THE UPPER LOWER CAMBRIAN BASTION AND ELLA ISLAND FORMATIONS, NORTH-EAST GREENLAND , 2006, Journal of Paleontology.

[5]  J. Bergström,et al.  THE MORPHOLOGY OF HYOLITHIDS AND ITS FUNCTIONAL IMPLICATIONS , 2005 .

[6]  J. Shergold,et al.  Changing perspectives on Cambrian chronostratigraphy and progress toward subdivision of the Cambrian system , 2005 .

[7]  G. Geyer.  The base of a revised Middle Cambrian: are suitable concepts for a series boundary in reach? , 2005 .

[8]  J. S. Peel,et al.  The problematic fossil Triplicatella from the Early Cambrian of Greenland, Canada, and Siberia. , 2004 .

[9]  J. S. Peel,et al.  Anabarella australis (Mollusca, Helcionelloida) from the Lower Cambrian of Greenland , 2004 .

[10]  Maoyan Zhu,et al.  Lower Cambrian Small Shelly Fossils of northern Sichuan and southern Shaanxi (China), and their biostratigraphic importance , 2004 .

[11]  C. Skovsted,et al.  Hyoliths and small shelly fossils from the Lower Cambrian of North-East Greenland , 2004 .

[12]  F. Sundberg,et al.  Early and Mid Cambrian trilobites from the outer‐shelf deposits of Nevada and California, USA , 2003 .

[13]  B. Waggoner.  NON-TRILOBITE ARTHROPODS FROM THE SILVER PEAK RANGE, NEVADA , 2003, Journal of Paleontology.

[14]  C. Skovsted.  The mollusc fauna of the Early Cambrian Bastion Formation of North-East Greenland , 2003 .

[15]  Instytut Paleobiologii.  Early Cambrian molluscs from glacial erratics of King George Island, West Antarctica , 2003 .

[16]  A. Gubanov.  Early Cambrian palaeogeography and the probable Iberia–Siberia connection , 2002 .

[17]  G. Geyer,et al.  LATEST EARLY CAMBRIAN SMALL SHELLY FOSSILS, TRILOBITES, AND HATCH HILL DYSAEROBIC INTERVAL ON THE QUÉBEC CONTINENTAL SLOPE , 2002, Journal of Paleontology.

[18]  G. Geyer,et al.  The quest for internationally recognized divisions of Cambrian time , 2000 .

[19]  F. Sundberg,et al.  PTYCHOPARIID TRILOBITES OF THE LOWER-MIDDLE CAMBRIAN BOUNDARY INTERVAL, PIOCHE SHALE, SOUTHEASTERN NEVADA , 2000 .

[20]  G. Shi,et al.  Palaeobiogeographic affinities of Australian Cambrian faunas , 2000 .

[21]  G. Brock.  Middle Cambrian molluscs from the southern New England fold belt, New South Wales, Australia , 1998 .

[22]  K. B. Ketner.  The nature and timing of tectonism in the western facies terrane of Nevada and California; an outline of evidence and interpretations derived from geologic maps of key areas , 1998 .

[23]  E. Landing,et al.  Oldest shelly fossils from the Taconic Allochthon and late Early Cambrian sea-levels in eastern Laurentia , 1996, Journal of Paleontology.

[24]  Js. Peel.  The classes Tergomya and Helcionelloida, and early molluscan evolution , 1991 .

[25]  G. Narbonne,et al.  The Placentian Series: appearance of the oldest skeletalized faunas in southeastern Newfoundland , 1989, Journal of Paleontology.

[26]  S. Bengtson,et al.  Palaeontology and biostratigraphy of the Early Cambrian Meishucunian Stage in Yunnan Province, South China , 1989 .

[27]  R. Robison,et al.  Taxonomy and paleobiology of some Middle Cambrian Scenella (Cnidaria) and Hyolithids (Mollusca) from western North America , 1988 .

[28]  J. S. Peel.  Molluscs of the Holm Dal Formation (late Middle Cambrian), central North Greenland , 1988 .

[29]  W. H. Fritz,et al.  Small shelly fossils and trace fossils near the Precambrian-Cambrian boundary in the Yukon Territory, Canada , 1985 .

[30]  D. Mackinnon.  New Zealand late Middle Cambrian molluscs and the origin of Rostroconchia and Bivalvia , 1985 .

[31]  H. Danielli.  The fossil alga Girvanella Nicholson & Etheridge , 1981 .

[32]  A. J. Rowell.  Early Cambrian brachiopods from the southwestern Great Basin of California and Nevada , 1977 .

[33]  B. Runnegar,et al.  Australian middle cambrian molluscs and their bearing on early molluscan evolution , 1976 .

[34]  W. Wenz.  Allgemeiner Teil und Prosobranchia , 1961 .

[35]  G. Matthew.  THE PROTOLENUS FAUNA. , 1894, Science.

[36]  H. A. Nicholson,et al.  A monograph of the Silurian fossils of the Girvan district in Ayrshire : with special reference to those contained in the "Gray collection" , 1878 .

[37]  H. Hicks.  On some Undescribed Fossils from the Menevian Group , 1872, Quarterly Journal of the Geological Society of London.