Tafonomia y paleoecologia de Tagelus plebeius Molluska Bivalvia en sedimentos holocenos del río Quequen Grande

GRISELDA GOLFIERI; LAURA FERRERO; MARCELO ZÁRATE

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 1998 vol. 35 p. 255 - 264

0002-7014

resumen The taphonomic history of Tagelus ptlebeias (Lightfoot) at the Holocene estuary of río Quequén Grande, Buenos Aires, Argentina, is analized. The high percentage of vertical articulated individuals with ligament preserved is the result of in sítu preservation. No evidences of abrasion were observed; high fragmentation percentages, both in horizontal articulated fossils and single valves, can be attributed to bioturbation and predation. The inclividuals in living position were preferentially oriented suggesting the occurrence of dominant palaeocu¡rents The size distribution of individuals in living position shows an almost complete absence of small specimens as a result of a higher taphonomic loss b¡'bioturbation sand/or selective predation of small sizes. The high densities of T.plebeius may indicate the superposition of different qenerations or populations and cannot be attributed to mass mortality. The concentrations are interpreted as the result of a gradually changing environment as well as of other biological factors such as predation and bioturbation.