NUEVOS TRILOBITES DEL OVETIENSE INFERIOR (CÁMBRICO INFERIOR BAJO) DE SIERRA MORENA (ESPAÑA)

Abstract

Trilobites from two lower Ovetian (low lower Cambrian) localities in Sierra Morena (south of Spain) are described. Serrania palaciosi nov. sp. and Serrania? gordaensis nov. sp. come from the western locality (Alconera). New specimens of Serrania verae Liñán Guijarro, 1978 come from the eastern locality (Sierra de Córdoba). The ontogenetic study of S. verae suggests that this species evolved from S. palaciosi. The new material allows us to include the genus Serrania within the new subfamily Serrinae defined herein, belonging to the family Bigotinidae. We include also two more genera with a lateral spine in the glabella, Hupetina and Sdzuyia. According to its stratigraphical position and the associated taxa, we can determinate that S. verae belongs to the Lemdadella linaresae Zone, corresponding to the lower part of the archaeocyatids Zone III. On the basis of stratigraphic and phylogenetic criteria, S. palaciosi nov. sp. and S.? gordaensis nov. sp. from Alconera belong probably to the Zone I of archaeocyathids. Some unclassifiable trilobite fragments have been also found in the Zone I of archaeocyathids at the Ovetian stratotype in Sierra de Córdoba, below the trilobite zone of Bigotina bivallata (which is equivalent to the trilobite Zone 0, or Eofallotaspis Zone, of Morocco). The new species defined herein are, up to now, the oldest trilobites described from Gondwana.