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Abstract The rosetted trace fossil Dactyloidites ottoi ( Geinitz, 1849 ) is reported and described for the first time from late Pleistocene (MIS 5e) carbonates of the Bahama Archipelago in shallowing-upward, shelly calcarenites from Great Inagua and Great and Little Exuma islands. The distinctive, fan-shaped D. ottoi specimens from the Bahamas, while not preserved in fine detail and not revealing a shaft, compare favourably in shape and size with specimens from other localities around the world, including the oldest well-documented specimens from the Jurassic of Argentina. D. ottoi is interpreted as a fodinichnion formed by the activity of a deposit-feeding worm, probably a polychaete, consuming marine-plant remains within host sediment. The late Pleistocene palaeodepositional environment of these carbonate sediments is interpreted as within the lower foreshore–upper shoreface zone in full marine, tropical waters. This discovery of D. ottoi marks an addition to the Bahamian shallow-marine ichnocoenose within the Skolithos ichnofacies.

Abstract Conch Bar Cave, Middle Caicos, comprises a series of large phreatic chambers open to the surface along the southern margin of an eolianite ridge. From these, phreatic passages run towards and terminate abruptly in the interior of the ridge, continuing in most cases only as centimeter-sized tubes. The simplest passages are elliptical tubes with relatively horizontal floors and ceilings punctuated by domes. Most passage sections are more complex, with remnants of former roof and floor levels. Some of these are bedding-concordant and lithologically controlled. But overall, there are strong modes present in the passage ceiling-elevation data, which suggest that the ceilings indicate past positions of the formative mixing zone or water table. The highest level present in the cave is more than 17 m above present sea level, and suggests either that there has been uplift of the platform or that past sea levels have been above this elevation. The eastern parts of the cave show submergence, while the western parts are dry. This suggests that there may have been tilting of the platform to the east toward the direction of the open-platform margin. Despite the size (>3 km surveyed passages) and antiquity of the cave (U-series age >195 ka obtained for a speleothem at sea level), its preservation potential in the geological record is low. The cave has been intercepted by surface lowering and back-wasting of the ridge, and the low mechanical strength of poorly cemented carbonates limits roof stability. Such caves may therefore be only rarely preserved as paleokarst cavities, more commonly being represented by residual cliffed embayments and breccia bodies, if at all. Under ice house conditions with frequent sea level changes, it is unlikely that any clear association between past sea-level still-stands and cave or enhanced porosity zones could be established from the rock record.