INVESTIGADORES
CASADIO Silvio Alberto
congresos y reuniones científicas
Título:
Decapoda (Crustacea : Brachyura) from the Puerto Madryn Formation (late Miocene) of Península Valdés, Argentina
Autor/es:
CASADIO, SILVIO; FELDMANN, RODNEY; PARRAS, ANA; SCHWEITZER, CARRIE
Lugar:
Puerto Madryn
Reunión:
Otro; Reunión Anual de la Asociación Paleontológica Argentina; 2005
Institución organizadora:
CEMPAT-APA
Resumen:
Five previously undescribed decapod taxa have been collected from early late Miocene rocks of the Puerto Madryn Formation, Península Valdés, Chubut Province, Argentina. New species are included in the genera Osachila, Rochinia, Romaleon, Panopeus, and Ocypode. Chaceon peruvianus and Proterocarcinus latus are also reported from the unit, in addition to two indeterminate xanthoid species. The material comes from the lowermost beds of the section exposed at Puerto Pirámide and Punta Pardelas just below high tide level. Sedimentologic and taphonomic evidence suggest that the crab-bearing rocks were deposited in an offshore, low-energy environment, below fair weather wave base, and in an area of relatively low sedimentation rate. Assignment of fossil taxa to genera within the Panopeidae is difficult due to the marked similarity in dorsal carapace characters among several genera. The species of Rochinia is the first record of the genus as a fossil, while the species of Osachila is only the second record of that genus to appear in the fossil record. The species of Ocypode is the oldest known fossil occurrence of the genus. The new species of Romaleon is the first fossil record of the genus on the Atlantic coast.