Capaldo and Blumenschine 1994A quantitative diagnosis of notches made by hammerstone percussion and carnivore gnawing on bovid long bonesWe start with the premise that for archaeologists, and especially the researchers focused on taphonomy and archaeozoology, it is important to distinguish between marks left by hominid actors and carnivore gnawings. The authors say that some of the methods developed for this task, like skeletal part profiles, carnivore to ungulate ratios, fragmentation indexes and fracture features are more ambiguous, so they rely on surface-modification studies that measure the presence or absence, frequency, morphology, and anatomical location of marks on bone surface. In this article, to establish the difference between percussion notches produced by hammerstone-anvil and tooth notches produced by carnivore gnawing, they decide to conduct an actualistic study, to reproduce both kinds of effects, and then compare them in frequency and structural characteristics.So, they start with a discussion of why it is important to conduct this kind of studies. Three factors have made difficult to distinguish between percussion and tooth notches. One is the failure to distinguish between percussion notches produced during bone-tool manufacture and those produced during marrow extraction. A second one is that most studies have characterizes notch shape qualitatively. And the third one is the failure to produce controlled experimental and other actualistic samples based on direct observation and controlling all the variables like bone size, skeletal element, and setting. As a result, they design this study to address all of these questions and control all these variables. The main research question is if dynamic loading produced normal notch morphologies and frequencies that are distinguishable from those produce by static loading.Then, they talk about the sample, which was formed by 50 normal carnivore tooth notches on 48 bovid long bone specimens and 103 normal hammerstone percussion notches on 90 specimens. They included only the six marrow-bearing bovid long bones. The samples were generated or collected in the Serengeti National Park and Ngorongoro Conservation Area of Tanzania. All bones were acquired fresh and broken on the day of acquisition or within two weeks of that, but it didn't matter because even when they were not fresh, the carnivores consumed them anyway. / Then they described the process of long bone processing, removing skin, flesh, fat and tendon, then disarticulating the bones, and placing them on the anvil. After the samples were collected, the specimens and the notches were analyzed, identifying bovid, size , taxon, skeletal element and form of the notch. They used two sets of measures to distinguish assemblages notched by carnivores or hammerstones. The first is the incidence of notched specimens in the assemblage, which is the proportion of the total number of specimens that bear at least one normal notch. And the second is notch morphology, defined by two shape measures that are based on ratios of three linear notch dimensions and platform angle. As we can see in page 733, these are:- Inflection points- Maximum notch breadth- Maximum notch depth- Maximum flake scar breadthand - Flake-scar lengthIn some cases they needed latex molds to get these measurements. Annnd... ok, the results. 1. First of all, there is a difference in number. On bovid size 1 and 2, there is a larger number of notched specimens in the percussion assemblages than in the carnivore assemblages. 2. There is also a difference in the degree of completeness. There are more complete notches in the carnivore sample than in the percussion sample.3. And there is a difference in morphology. On bovid size 1 and 2, the notches caused by hammering were broader and shallower, and the carnivorous gnawings had a semicircular plan form. The flakes removed from percussion notches were significantly thinner than those removed from carnivore notches, and the release angles for these flakes from percussion notches are more obtuse than the carnivore ones, which are closer to perpendicular.Then. they discuss the processes of static and dynamic loading, the types of force applied by the effectors (hammers and teeth) to produce the notches. The impact of hammerstone-on-anvil produce dynamic loading, and gnawing produce static loading (make gesture and explain: the effect of hitting on a surface, a sudden force applied to the object, against the effect of holding the object and apply force on it from these two points).p. 739. Of course this is affected by the size and thickness of the bone. Finally, they point out the advantages of this kind of studies. First, They can be used to infer autorship of the samples. Also, these are traces produced during the consumption of nutrients in the bone an are not produced in other stages. And they propose to conduct more of these actualistic studies to control for other variables like roof fall, and subaerial and diagenetic processes in general.