Remarkably preserved annelid worms from the La Meseta Formation (Eocene), Seymour Island, Antarctica |
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Authors: | CARRIE E. SCHWEITZER RODNEY M. FELDMANN SERGIO MARENSSI DAVID A. WAUGH |
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Affiliation: | Department of Geology, Kent State University Stark Campus, 6000 Frank Avenue Northwest, Canton, OH 44720, USA;e-mail; Department of Geology, Kent State University, Kent, OH 44242 USA;e-mail: and; Instituto Antártico Argentino, Cerrito, 1248 Buenos Aires 1010 Argentina;e-mail: |
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Abstract: | Abstract: Worm tubes, which exhibit the replaced tube-lining membrane, have been collected from the lowermost Lower Eocene Acantilados Allomember of the La Meseta Formation, Seymour Island, Antarctica. The discovery represents the oldest examples of preservation of the tube-lining membrane of tube-dwelling Polychaeta in the fossil record. A new genus and species, Caprascolex antarcticus , are described. The specimens are preserved as thin coatings of amorphous iron oxide on the inner surface of the moulds interpreted to be the replaced tube-lining membrane. Examination of the rarely described tube-lining mucosoid membrane in extant polychaetes shows that the fossils are nearly identical in morphology and scale to extant forms. These fossils record in remarkable detail the morphology of the tube-lining membrane, which appears to be composed of growth bands formed as the worm constructed the tube. The tube-lining is believed to have been originally preserved as pyrite, with subsequent oxidation to iron oxide. The tube-lining membrane of worm tubes possibly is known from only one other fossil occurrence. |
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Keywords: | Eocene La Meseta Formation Seymour Island Antarctica Annelida Polychaeta worm |
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