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Remarkably preserved annelid worms from the La Meseta Formation (Eocene), Seymour Island, Antarctica
Author(s) -
SCHWEITZER CARRIE E.,
FELDMANN RODNEY M.,
MARENSSI SERGIO,
WAUGH DAVID A.
Publication year - 2005
Publication title -
palaeontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.69
H-Index - 63
eISSN - 1475-4983
pISSN - 0031-0239
DOI - 10.1111/j.1475-4983.2004.00440.x
Subject(s) - extant taxon , annelid , paleontology , fossil record , geology , tube (container) , pyrite , morphology (biology) , biology , anatomy , geochemistry , materials science , evolutionary biology , composite material
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.