CICTERRA   20351
CENTRO DE INVESTIGACIONES EN CIENCIAS DE LA TIERRA
Unidad Ejecutora - UE
artículos
Título:
A new genus and species of Heroini (Perciformes: Cichlidae) from the early Eocene of southern South America
Autor/es:
ALANO PEREZ, P; MALABARBA, C; DEL PAPA C
Revista:
NEOTROPICAL ICHTHYOLOGY
Editorial:
SOC BRASILEIRA ICTIOLOGIA
Referencias:
Año: 2010 vol. 8 p. 631 - 642
ISSN:
1679-6225
Resumen:
The Lumbrera Formation is the uppermost unit of the Salta Group, which crops out in northwestern Argentina. The
paleoenvironment of the Lumbrera Formation is interpreted as a perennial lake deposited under temperate climatic conditions
during the early to middle Eocene. Its fossil content is made up of palynomorphs, insects, crocodiles, turtles, lizards, and
mammals, besides an ichthyofauna formed by cichlids, poeciliids and dipnoans. Plesioheros chauliodus is described based
on a single individual from this formation, which was fossilized as a lateral view impression (missing anal and caudal fins). It
can be distinguished from other cichlids by a moderately deep body, enlarged anterior dentary teeth bearing subapical cusp,
a low abdominal vertebral count (10), five canal openings in the dentary, and XI + 12 dorsal-fin rays. A phylogenetic analysis,
using the matrix by Kullander (1998), recovered Plesioheros within Heroini. This species was recovered most closely related
to Australoheros and to the deep-bodied South American heroins. The occurrence of an Eocene Heroini, as well as of other
cichlid lineages in the same stratigraphical level, is evidence of an ancient diversification in this family. This ancient age
supports the hypothesis that the Cichlidae originated on Gondwana.