Description of well-preserved, but fragmentary, millipedes from the Red Hills Road Cave, Jamaica (Late Pleistocene)

摘要

The Red Hills Road Cave (RHRC) of Jamaica contains many millipede fossils: Chondrotropis sp., Rhinocricus spp., Caraibodesmus verrucosus (Pocock), and Haplocyclodesmus sp. cf. H. porcellanus (Pocock) have been identified hitherto. The RHRC is about 40,000 to 25,000 years old, and is filled with unlithified sediment composed of a mixture of terra rossa and limestone clasts, making it an excellent environment for carbonate mineralization of calcitic fossils. Since the initial publication 25 years ago, little has been added to our knowledge of the mode of preservation of the millipedes. In the present study, nine specimens have been observed by revisiting scanning electron microscopy. Observed structures include segmentation, legs, mouth parts, antennae and anal plates. Smaller external structures, such as ozopores and spiracles, have been lost under calcitic deposits. Whilst in the RHRC these millipedes were presumably exposed to unstable levels of overburden whilst covered by sediment, but this has not caused a noticeable deterioration of specimens. The quality of the preserved specimens is generally good, albeit fragmentary.