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View - Kowalewski, M. - Virginia Tech

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PALEONTOLOGICAL SOCIETY PAPERS, V. 8, 20021993). The drilling frequencies in some Cretaceoussamples equal or exceed those observed in earlyCenozoic samples from the Gulf Coastal Plains(Kelley and Hanson, 1993, 2001; Kelley et al., 2001;see discussion below). These studies are possiblebecause naticids leave a unique type of countersunkdrillhole in scaphopod, bivalve, gastropod, andconspecific gastropod prey, as well as otherorganisms (Carriker and Yochelson, 1968; Sohl,1969; reviewed by Kabat, 1990; <strong>Kowalewski</strong>, 1993).Muricids (Neogastropoda) also evolved in theLate Cretaceous; predaceous muricids producecharacteristic cylindrical, non-chamfered boreholes(Fig. 8.3). Muricids form an ecletic gustatorygroup, ranging from herbivores to carrion feeders;however, most are shell drillers (Kabat, 1990).Shell drilling is most likely a pleisomorphicbehavioral trait within the Muricidae, although notall muricid genera bore through hard exoskeletons(Vermeij and Carlson, 2000). In contrast to naticidFIGURE 7—Diversification patterns of shell drilling through time: upper figure shows diversity of drillinggastropod clades through the Mesozoic and Cenozoic eras; lower figure shows frequency of drilledprey per million years through the Phanerozoic. Adapted from Sohl (1969) and <strong>Kowalewski</strong> et al. (1998).140

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