PERSONAL DE APOYO
REGUERO Marcelo Alfredo
artículos
Título:
Fossilized spermatozoa preserved in a 50-Myr-old annelid cocoon from Antarctica
Autor/es:
BOMFLEUR, BENJAMIN; MÖRS, T.; FERRAGUTI, MARCOS; REGUERO, M.A.; MCLOUGHLIN, STEPHEN
Revista:
BIOLOGY LETTERS
Editorial:
ROYAL SOC
Referencias:
Lugar: Londres; Año: 2015 vol. 11 p. 1 - 5
ISSN:
1744-9561
Resumen:
The origin and evolution of clitellate annelids?earthworms, leeches andtheir relatives?is poorly understood, partly because body fossils of thesedelicate organisms are exceedingly rare. The distinctive egg cases (cocoons)of Clitellata, however, are relatively common in the fossil record, althoughtheir potential for phylogenetic studies has remained largely unexplored.Here, we report the remarkable discovery of fossilized spermatozoa preservedwithin the secreted wall layers of a 50-Myr-old clitellate cocoon fromAntarctica, representing the oldest fossil animal sperm yet known. Spermcharacters are highly informative for the classification of extant Annelida.The Antarctic fossil spermatozoa have several features that point to affinitieswith the peculiar, leech-like ?crayfish worms? (Branchiobdellida). Weanticipate that systematic surveys of cocoon fossils coupled with advances innon-destructive analytical methods may open a new window into the evolutionof minute, soft-bodied life forms that are otherwise only rarelyobserved in the fossil record.
