Recent warnings concerning paleobiological inferences based upon gastr
opod shell morphology (Houbrick 1991) merit serious consideration, alt
hough the dangers have been overstated, Ratchet sculpture, an asymmetr
ical sculpture that assists marine invertebrates in burrowing, is not
qualitatively different from sculptures that apparently do not aid in
burrowing. Therefore, the interpretation of such sculpture might be pr
oblematical. Nevertheless, the large body of empirical evidence demons
trating the function of ratchet sculpture in burrowing by bivalves, ga
stropods, carpoid echinoderms, brachiopods, and arthropods and the lac
k of evidence supporting alternative functions in the Gastropoda warra
nt the continued, although cautious, association of ratchet sculpture
with burrowing in marine gastropods.