Earlier (late Pliocene) first appearance of the Caribbean reef-building coral Acropora palmata: Stratigraphic and evolutionary implications
Abstract
An integrated stratigraphic study of reefal deposits on the Caribbean side of the Isthmus of Panama (Limon, Costa Rica) has discovered a significantly earlier first appearance of the major reef-building coral Acropora palmata</em>. A. palmata</em> is here reported from the early late Pliocene, constrained in age to within the Gauss chron (ca. 3.6 2.6 Ma). This coral was previously thought to have originated in the earliest Pleistocene and has subsequently been used as a Quaternary marker throughout the Caribbean and the Bahamas. An earlier appearance in the southern Caribbean implies a diachronous first appearance datum relative to the northern Caribbean. This older age also places A. palmata</em> well within the transition phase of a Pliocene (4 1 Ma) faunal turnover that was marked by widespread extinction and origination of Caribbean coral species. An early late Pliocene origination is coincident with formation of the Isthmus, climate reorganization, and frequent sea-level changes associated with onset of Northern Hemisphere glaciations. The rapid growth and accumulation rates that characterize A. palmata</em> may therefore be adaptive to these fluctuating environmental conditions, enabling its success during the subsequent Pleistocene glacial cycles.
- Publication:
-
Geology
- Pub Date:
- October 1997
- DOI:
- 10.1130/0091-7613(1997)025<0891:ELPFAO>2.3.CO;2
- Bibcode:
- 1997Geo....25..891M