383 Late Miocene to Pleistocene reef corals in the Gulf of California

A new collection of fossil reef corals from the late Miocene Imperial Formation, the early Pliocene San Marcos Formation, the middle to late Pliocene Carmen Formation, and the Pleistocene, Gulf of California, Mexico, has yielded four new species. Additionally, new occurrences of previously described species are reported. Morphometric analysis failed to distinguish between S. californica Vaughan, 1917, and S. mendenhalli Vaughan, 1917, therefore the former is synonymized with the latter. The fauna occurred either in low-angle ramps or flat-lying terraces of variable extension. Most outcrops were small, and reminiscent of more extensive deposits usually formed in open, exposed, high-energy environments. However, well preserved units deposited in protected embayments are also present. Except at Isla Coronados and La Ventana where multiple coral terraces occur, coral bearing units represent single spatiotemporal growth episodes. The present analysis shows that the reef coral fauna between late Miocene to late Pleistocene in the Gulf of California can be considered depauperate when compared to the Caribbean fauna; nonetheless, it bears many more species than previously thought.

Ramón Andrés López-Pérez

Pages: 78 pp, 21 text-figs, 15 tables, 13 pls., 1 appendix

Issue: BAP 383

Year published: 2012