Silurian and Devoniana molluscan bivalves from Precordillera region, western Argentina

SÁNCHEZ, T.M. ; WAISFELD, B.G.; TORO, B.A.

JOURNAL OF PALEONTOLOGY

PALEONTOLOGICAL SOC INC

Lugar: Lawrence; Año: 1995 vol. 69 p. 869 - 886

0022-3360

Silurian and Devonian bivalves recovered from the Los Espejos (Silurian to Lower Devonian) and Talacasto (Devonian) Formations of the northern Precordillera Mountain belt are described and illustrated. The fauna comprises some new nuculoids Deceptrix (Devonodeceptrix) jachalensis n.subgen and n.sp. Nuculites argentinum n.sp., and Anthracoleda (Pseudoleda) minuta n.subgen and n.sp., as well as the new pteroid Actinopteria modesta n.sp. Additionally, many poorly known South American bivalves are redescribed and figured. Silurian-Devonian pelecypod faunas from some South American localities show differences both in diversity and in faunal composition. Causes for these differences are briefly discussed. Controls other that latitude are suggested in order to explain biogeographical affinities of the studied fauna.