View - Kowalewski, M. - Virginia Tech

PALEONTOLOGICAL SOCIETY PAPERS, V. 8, 2002we can suggest some approaches that might provefruitful. One matter worth exploring is the incidenceof bite marks in dinosaur bones, or teeth embeddedin bone. Such fossils have already been noted forthe Late Cretaceous of western North America(Jacobsen, 1997, 1998, 2001), but older formationscould also be surveyed. Similarly, paleontologistsshould keep their eyes open for potential theropodcoprolites. With sufficiently large sample sizes oftooth-marked bone and coprolites, it might bepossible to determine which species of herbivorousdinosaurs, and which size classes within thosespecies, were preferentially eaten by which predatorspecies. If we were really lucky, we might even find,say, a bite mark unambiguously made by aTyrannosaurus that had healed, which wouldestablish beyond doubt that these predatorydinosaurs at least sometimes attacked live prey.Unfortunately, distinguishing successful predationevents from scavenging on the basis of toothmarkedbones is probably impossible, because thevictim cannot recover from either.Structural analysis (including computermodeling) of a variety of theropod skulls inparticular faunas (cf. Henderson, 2000; Rayfieldet al., 2001) could be used to test whetherreconstructions of different biting and/or feedingstyles in sympatric theropod species aremechanically feasible, and thus ways in whichcoexisting species could have subdivided theresource base. Such approaches could be combinedwith analyses of tooth shape, tooth cutting edges,and wear and breakage patterns, in both in situ andshed theropod teeth (Farlow et al., 1991; Farlow andBrinkman, 1994; Abler, 1997). The degree of sizeand shape overlap of the skulls and teeth of differentspecies of potentially sympatric theropods couldbe compared with that in modern communities ofpredatory lizards (e.g., the varanids of Australia)and crocodylians.With a better understanding of the systematiccomposition of dinosaur faunas, we could see howthe different composition of the prey base insauropod-dominated and ornithischian-dominatedFIGURE 4—Right lateral view of the pelvis of a moa (Canterbury Museum Av 8317, Emeus crassus)showing an elliptical gouge (arrow) dug by the hind toe talon of Harpagornis, a huge, extinct eagle. Thepaper label is 102 mm long. Photograph courtesy of Richard Holdaway.260