The fossils from Sawmill Sink open up unparalleled opportunities for doing much more sophisticated work than ever before in reconstructing the ancient plant and animal communities of the Bahamas, Steadman said. It helps us to understand not only how individual species evolve on islands, but how these communities changed with the arrival of people because we know that changes in the ecosystem are much more dramatic on islands than they are on continents.
There are many blue holes on Abaco and other Bahamian islands, but this is the first to be the site of a sophisticated fossil excavation, Steadman said. Although the Bahamian government has gone to great lengths to protect its coastline, blue holes with their submerged cave passages have received little attention as a marine resource, he said.
The fossil site is especially valuable because of the presence of fossilized plants -- leaves, twigs, flowers, fruits and seeds -- pollen and spores, and vertebrates, giving evidence of both the islands flora and fauna, Steadman said.
In a typical vertebrate fossil site, you identify the species of vertebrates -- reptiles, birds or mammals -- and based on that identification you speculate what the habitat might have been, he said. For the first time here in the West Indies, we have here on Abaco plant fossils right in with the vertebrates, so we can reconstruct the habitats in a much more sophisticated way.
For instance, because bracken ferns are one of the first plants to recolonize after a fire, the presence of their spores would indicate regular burning in prehistoric times and indicate that an area was grassland. Evidence for this also comes from the numerous fossils of burrowing owls or meadow larks, which prefer open habitats, he said.
Among the excavations findings are that the land-roaming Cuban crocodile lived in the Bahamas until humans arrived, S
|Contact: David Steadman|
University of Florida