CALL FOR PROPOSALS:

ORGANIZERS

  • Harvey Thorleifson, Chair
    Minnesota Geological Survey
  • Carrie Jennings, Vice Chair
    Minnesota Geological Survey
  • David Bush, Technical Program Chair
    University of West Georgia
  • Jim Miller, Field Trip Chair
    University of Minnesota Duluth
  • Curtis M. Hudak, Sponsorship Chair
    Foth Infrastructure & Environment, LLC

 

Paper No. 20
Presentation Time: 9:00 AM-6:00 PM

FOUR NEW CRINOIDS FROM THE LOWER DEVONIAN OF BOLIVIA


THOMPSON, Jeffrey R., Department of Earth Sciences, The University of Southern California, Columbus, OH 43235 and AUSICH, William I., School of Earth Sciences, Ohio State University, 155 S Oval Mall, Columbus, OH 43210-1398, thompson.1983@buckeyemail.osu.edu

Little is known of crinoid faunas from the Lower Devonian of South America; therefore, the four new Lower Devonian crinoids reported here from Bolivia are important discoveries. Two new taxa are reposted from the Icla Formation at Cerro Kochis in the Cochabamba Department. One of these new taxa has been identified as a new genus of Rhodocrinitid, the other has been identified as a new species of Griphocrinus. Two additional camerates are reported from the Belèn Formation of the Altiplano region in the La Paz Department. One of which is a new species of Ctenocrinus and the other is a Rhotocrinitid. In addition, a poorly preserved blastoid was recovered from the Altiplano region. These crinoids are described using systematic taxonomy. These taxa were previously unknown from South America. The specimens from the Cochabamba Department are from below the Francovichia zone and preserved in a micrite matrix. The specimens from the Altiplano are from silty mudstones. The specimens give us new insight into the Lower Devonian of Bolivia, a relatively new frontier in Crinoid research. The presence and diversity of the specimens indicate that there are likely more extensive crinoid faunas in Bolivia than previously expected, and that the Emsian period of Bolivia may be important in the expansion of known Crinoid taxa.
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