View - Kowalewski, M. - Virginia Tech

CLOSING REMARKSTHE FOSSIL RECORD OF PREDATION:METHODS, PATTERNS, AND PROCESSESThe papers assembled in this volume showcompellingly the methodological, topical, andconceptual richness of paleontological research onpredation. Such studies span a broad spectrum oforganisms and a wide range of observational scales,from individual interactions to global-scale seculartrends. The fossil record offers us diverse andprovocative evidence of predator-prey interactionsthrough time, ranging from predation traces tofunctional morphology and phylogenetic affinities.In recent years, these diverse data have become abase for posing increasingly sophisticated questionsand for testing increasingly complex hypotheses.As clearly demonstrated in this volume,predation can be defined in a variety of ways. Apredator can be defined very broadly as “anorganism killing another organism for nutritionalpurposes” (Bengtson; see also Labandeira; Lippsand Culver; Brett and Walker), or the definitionmay be restricted behaviorally by excludingorganisms that kill by passive filter-feeding, so thatpredators are only “those organisms that hunt ortrap, subdue, and kill individual animals that havesome capacity for either protection or escape”(Bambach; see also Kowalewski). Predation as aconcept may be restricted to macro-carnivory—with a predator then defined as “a large animal orsometimes a plant consuming part or the whole ofanother animal” (Vermeij)—or can be expandedto include tiny organisms, like foraminiferasubduing and eating larger animals (Lipps andCulver), or even behaviors that involve the killingof plants (e.g., seed predation; Labandeira). Thus,the definition of predation varies significantlyamong researchers. The term predation may alsoinclude related behaviors along a spectrum fromactive predation to scavenging, from lethalpredation to partial (sublethal) predation,parasitism, and amensalism (see Baumiller andGahn; Labandeira; Kowalewski; Vermeij).METHODSThe chapters included in the first part of thevolume review a variety of methods that can beapplied to study the fossil record of predation.Various direct and indirect indicators of predationare available to paleontologists, including tracefossils, coprolites, gut contents, exceptionalpreservational events, taphonomic patterns, andindirect evidence provided by functionalmorphology and phylogenetic affinities(Kowalewski). Because of the highly disparatenature of the data itself, variable research goals,and even personal idiosyncrasies, the methodsused to study ancient predator-prey interactionsare very diverse.Among various lines of evidence, trace fossilsleft by predatory activity offer a particularly richsource of quantifiable data (Kowalewski; see alsoHaynes; Lipps and Culver; Brett and Walker; Walkerand Brett; Baumiller and Gahn; Farlow and Holtz;Bengtson; Dietl and Kelley; Vermeij); and variousanalytical approaches for studying trace fossils canbe fruitful depending on the nature of the materialand the scientific goals of paleontological projects(Kowalewski). Coprolites and stomach contents alsoprovide a wealth of direct data on ancient predatorpreyinteractions and are widely used for studyingthe diet of ancient predators, from marine invertebratesto terrestrial vertebrates (Chin; see also Brettand Walker; Walker and Brett; Labandeira; Farlowand Holtz). In addition to the predation traces studiedby paleontologists, anthropologists have developeda distinct set of qualitative and quantitative methodsfor studying the hunting behavior of hominids, notonly to distinguish between scavenging andpredation, but also to draw the much more subtledistinctions among different butchering behaviors,such as skinning, meat-stripping, or sectioning ofanimal carcasses (Haynes).395