SCLEROBIONTS ON PATAGONIAN OYSTERS FROM THE PUERTO MADRYN FORMATION (EARLY-LATE MIOCENE, ARGENTINA)

Authors

  • María Virginia Romero Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, Consejo Nacional de Investigaciones Científicas y Técnicas, Avenida Roca 1242, R8332FDL, General Roca, Argentina
  • Soledad Silvana Brezina Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, Consejo Nacional de Investigaciones Científicas y Técnicas, Avenida Roca 1242, R8332FDL, General Roca, Argentina
  • Claudia Silvia Bremec Estación Costera Juan José Nágera, Instituto de Investigaciones Marinas y Costeras Consejo Nacional de Investigaciones Científicas y Técnicas / Universidad Nacional de Mar del Plata, Rodríguez Peña 4046, 7600, Mar del Plata, Argentina
  • Silvio Casadío Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, Consejo Nacional de Investigaciones Científicas y Técnicas, Avenida Roca 1242, R8332FDL, General Roca, Argentina

Keywords:

SW Atlantic Ocean, Tortonian, Patagonia, Boring and encrusting organisms, Oyster beds.

Abstract

This work describes the composition and distribution of sclerobionts on the Miocene Patagonian oyster Ostrea alvarezii d’Orbigny and provides information about its paleoenvironment. The structure of sclerobiont assemblages and their preferential distribution on left/right valves (n=340) as well as their external/internal surfaces and areas was evaluated by means of multivariate analyses (nMDS, SIMPER), non-parametric tests for producing mean comparisons, and goodness of fit tests using coverage and abundance data. Sixteen ichnotaxa were recorded. Bivalves, polychaetes and bryozoans were the most representative encrusters. External surfaces, left valves and sediment-free areas were the most colonized. O. alvarezii beds are interpreted as within-habitat time-averaged assemblages. Oysters appear to have lived in small subtidal channels in a low energy tidal flat and closely related to the sediment-water interface, with the right valve resting on the substrate. Sclerobionts showed diverse behaviors, trophic levels and tiering. This suggests that sclerobiont assemblages on O. alvarezii had a complex structure with subdivision of resources, including a vertical colonization of valves by tracemakers at different levels of depth.

Published

2018-05-18

How to Cite

Romero, M. V., Brezina, S. S., Bremec, C. S., & Casadío, S. (2018). SCLEROBIONTS ON PATAGONIAN OYSTERS FROM THE PUERTO MADRYN FORMATION (EARLY-LATE MIOCENE, ARGENTINA). Ameghiniana, 55(2), 179–196. Retrieved from https://ameghiniana.org.ar/index.php/ameghiniana/article/view/3081

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