Early to Middle Miocene shallow-water corals from La Guajira, Colombia

Abstract

Here we describe and illustrate 31 Miocene corals species from the Siamaná and Jimol Formations that were collected over two expeditions in the Guajira basin, Colombia during 2011 and 2014. Corals include 25 species, derived from 15 different genera and 12 families. Six of them remain with open nomenclature. From the 25 species found in the study area, 88% are extinct and the remaining under endanger status. Most of the species are hermatypic components of the Scleractinian order, with the exception of a member of the Milleporidae family. The corals described are composed of typical taxa from the Oligocene-Miocene transition, during which they were important components in building fringing and patch reefs in the circum-Caribbean/Gulf of Mexico region. The presence of typical Oligocene coral taxa such as Agathiphyllia spp., Antiguastrea sp., and Diploastrea spp. from La Guajira extend the distribution of these genera into the Miocene, adding a more recent geological presence in the Southern Caribbean. Coral assemblages suggest a development in clear, calm and shallow waters, under oligotrophic conditions and only moderate physical disturbance. Our descriptions represent the first effort to characterize the taxonomy of fossilized corals in Colombia.