CONTRASTING PATTERNS OF PRESERVATION IN A JAMAICAN CAVE

The Red Hills Road Cave (or fissure), parish of St Andrew, near Kingston, Jamaica, is an insignificant remnant of a karstic feature that was quarried away during road building before the mid-1980s. Nevertheless, it is the most important site for Late Pleistocene terrestrial palaeontology on the island. The site is about 30,000 years old (oxygen isotope stage 3), but may span at least 15,000 years. Many taxa were probably washed in during hurricanes and tropical storms, either as dead skeletons or live organisms that drowned as the cave filled with water.

The invertebrate fauna includes both land snails and arthropods, largely or entirely derived from the surrounding area; none are obligate cave dwellers. The 62 species of land snails are the most diverse of any Jamaican cave; about half the snails in the cave live in the local area today. The arthropods include the only fossil millipedes, isopods and insects (fly puparia, beetle elytra) in the Jamaican fossil record, in addition to a land crab. Millipedes and isopods are well preserved because of a diagenetically early coating of calcite cement. The exoskeletons of these groups contain a small, but significant, calcite component not found in insects, spiders and scorpions.

The vertebrate fauna remains remain understudied, but include a rodent, three species of bat and possibly a marsupial; a flightless ibis, the Jamaican tody and various other birds; and reptile and amphibian remains. In contrast to the arthropods, the vertebrates are invariably disarticulated, apart from rare crania, jawbones retaining teeth and bones that are fused in life. A dead millipede could be coated in calcite when floating in the cave; a dead vertebrate carcass would have to rot to expose its bones, likely after the cave dried out.