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Cyclostremiscus sp. |
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Scanning electron micrographs (SEM) of Fossil specimens |
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| Lower Pinecrest beds, Upper Tamiami Formation, Sarasota County, Florida. SEMs produced in collaboration with Dr. Ann Heatherington, Dept. Geological Sciences, University of Florida, Gainesville, FL. | |
This taxon differs from Cyclostremiscus jeannae Pilsbry and McGinty, 1946 Jeanne’s Vitrinella by having a more depressed profile and a wider, more perspective umbilicus. Unlike C. jeannae, the peripheral cord becomes obsolete in more mature shells. This apparently un-named taxon is probably ancestral to Cyclostremiscus vanbruggeni De Jong and Coomans, 1988, from which it differs most conspicuously by its larger umbilicus. |
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| Cyclostremiscus bartschi (Mansfield, 1930) |
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1.33 mm. |
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1.20 mm. |
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1.33 mm. |
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1.00 mm. |
| Cochran Pit, Caloosahatchee Formation, LaBelle, Hendry County, Florida. SEMs produced in collaboration with Dr. Ann Heatherington, Dept. Geological Sciences, University of Florida, Gainesville, FL. | |
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| Caloosahatchee Formation, St. Petersburg, Pinellas County, Florida (1.60 mm.). SEM produced in collaboration with Dr. Ann Heatherington, Dept. Geological Sciences, University of Florida, Gainesville, FL. | |
Cyclostrema bartschi was described from the "Upper Miocene of Harvey's Creek, Leon Co., Florida," which is now known to be the Late Pliocene Jackson Bluff Formation (3.6 to 2.6 MYA) and contemporaneous with the Pinecrest beds. Olsson and Harbison (1953: 425-426; pl. 54: figs. 2, 2a, 2b, 3, 3a, 4, 4a) recognized this species as in the Caloosahatchee Formation of St. Petersburg, FL (1.8 to 2.6 MYA). Records of this Plio-Pleistocene species in the Recent fauna cited by Rubio et al. (2011: 95-96: Treece, 1980 and Rios, 2008) were unsubstantiated, have not been confirmed, and are likely based on misidentifications. De Jong, K. M. and H. E. Coomans, 1988. Marine gastropods from Curaçao, Aruba and Bonaire. E. J. Brill, Leiden, v + pp 1-261 incl. 47 pls. Mansfield, W.C., 1930. Miocene gastropods and scaphopods of the Choctawhatchee Formation of Florida. Florida Geological Survey Bulletin 3: 189 pp. Olsson, A.A. and A. Harbison, 1953. Pliocene Mollusca of southern Florida. Monograph No. 8 Academy of Natural Sciences of Philadelphia. v + pp. 1-457 + 65 pls. Rubio, F., R. Fernández-Garcés, and E. Rolán, 2011. The family Tornidae (Gastropoda: Rissooidea) in the Caribbean and neighboring areas. Iberus 29(2): vii + 1-230. December. |
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