Fish-otoliths from the early Miocene of the Castillo Formation, Venezuela: a view into the proto-Caribbean teleostean assemblages

Abstract

We describe the otolith assemblage from the early Miocene (Burdigalian) exposures of the Castillo Formation at the Cerro La Cruz locality (Falcón Basin, Lara State, northwestern Venezuela). The samples were obtained through surface and bulk sampling at distinct stratigraphic levels of the study area. The otolith assemblage from Cerro La Cruz includes 14 families, 25 genera and 30 taxa, of which 20 are reported for first time from the Castillo Formation. These include two new sciaenid taxa, Ctenosciaena angusticaudata nov. sp. and Pareques laraensis nov. sp. The Castillo Formation otolith assemblage represent fishes typical of shallow and near-shore and coral reef associated environments as characterized primarily by a high taxonomic diversity and abundance of Sciaenidae, and the lack of mesopelagic families (Myctophidae). The faunal composition of Cerro La Cruz is similar to other chronological equivalent sedimentary units along the proto-Caribbean area (Pirabas and Cantaure formations; Brazil and Venezuela respectively), though the Castillo Formation fish fauna shows lower taxonomic diversity, suggesting some heterogeneity of the coastal and near shore marine environments along the southern portion of the proto-Caribbean.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:B79F51B8-BC35-4119-8957-84544286868D

Keywords:

• Otoliths
• early Miocene
• Castillo Formation
• Venezuela
• Sciaenidae

Acknowledgements

We wish to thank to Instituto del Patrimonio Cultural (IPC), Venezuela, for permission for this project. We thank to Sr. P. Gómez†, Ing. M.E. Mendoza, Lic. M. López and Dr. F. Urbani with their help and camaraderie during the field trips. We also want to recognize the support given by Myloa Morgado-Vargas in the SEM Lab of Chemical Center at IVIC. We are grateful for the helpful comments and suggestions by Dr. Werner Schwarzhans, one anonymous reviewer, and the editors that helped with improving the clarity of the manuscript. Thanks to H.G. McDonald for correcting the English and suggestions to the final manuscript.