FIRST REPORT OF EUTHYNEURA (HETEROBRANCHIA: GASTROPODA) IN THE EARLY JURASSIC OF SOUTHERN PATAGONIA, ARGENTINA

FERRARI MARIEL

ANDEAN GEOLOGY

SERVICIO NACIONAL GEOLOGIA MINERVA

Lugar: Santiago de Chile; Año: 2023 p. 291 - 301

0718-7092

The present paper aims at the description of twonew species of Euthyneura (Heterobranchia: Gastropoda) in the Early Jurassic (earlyPliensbachian) marine deposits of the Chubut Basin at southern Patagonia,Argentina. The new species Cossmanninaaustralis nov. sp. and Cylindrobullinacaquelensis nov. sp. were found at the Cerro Caquel locality located in thewestern slope of Sierra de Tecka and Río Tecka valley. The new locality yieldedthe ammonite Eoamaltheus sp. (E. meridianus Hillebrandt Zone, upper part of Ibex Zone to Davoei Zone)which allowed to assign an early Pliensbachian age for the marine deposits at the studied area,providing also new evidence of the oldest record within the Early Jurassic inthe Sierra de Tecka region. The new report of Euthyneura in the Chubut Basinextends the palaeobiogeographical distribution of this clade into the southern hemisphereduring the earliest Pliensbachian.