Oryx gazella (Linnaeus, 1758)

Brophy, Juliet K., de Ruiter, Darryl J., Fortelius, Mikael, Bamford, Marion & Berger, Lee R., 2016, Pleistocene Bovidae (Mammalia) from Malapa, Gauteng Province, South Africa, Palaeontologia Electronica 35 (8), pp. 1-22 : 3-4

Oryx gazella

Neotragini Raphicerus campestris

Oreotragus oreotragus

Pelea capreolus

Ourebia ourebi

Antilopini Antidorcas marsupialis bovid teeth. The program quantifies the occlusal surface of the tooth and allows it to be compared with the reference database. While the tooth might represent an extinct species, similarities exist in teeth that are in the same tribe; therefore, EFFA can be used to help identify a tooth at the tribe and genus/species level.

Analyses of the phytoliths were performed on a sample of bovid teeth in order to determine if phytoliths could be recovered and used to aid in identifications and to obtain information on their feeding ecology. Plants produce silica bodies, or phytoliths, that maintain morphology specific to taxa. With good preservation, these biogenic silica bodies can be recovered from the dental calculus of bovid teeth and used to assess diet (see Piperno, 2006; Henry et al., 2012). In the palynology laboratory at the University of Witwatersrand, phytoliths were extracted from the calculus using the following method: a 10% solution of sodium hexameta- phosphate (Calgon) was added to each sample to deflocculate the calculus and assist diffusion. After 24 hours, the sample was sonicated for 5 minutes, centrifuged at 2000 rpm for 2 minutes, and the supernatant removed. Next, the sample was rinsed twice with distilled water. To dissolve the calculus, a 10% solution of hydrochloric acid was added and left for approximately 12 hours, and then rinsed twice in distilled water (see Henry et al., 2012). The remaining sample was mounted on a microscope slide in a 1:4 glycerine/ water solution and examined under a light microscope at 400 x magnification. Identified phytoliths are described using the terms recognized by the International code for phytolith nomenclature by using their geometric shapes and, when possible, texture/ornamentation and anatomical origin (see Madella et al., 2005 for full list).

While proper analysis of the mesowear is excluded by the small sample size, qualitative analyses of palaeodiet based on the mesowear approach were performed on the bovid teeth. These analyses rely on occlusal relief and cusp shape as reflections of the amount of attrition and abrasion that occurred on the occlusal surfaces of the tooth due to diet. Mesowear was recorded by examining the buccal (maxillary) and lingual (mandibular) apices of molar tooth cusps and scoring them as being sharp, rounded, or blunt depending on the degree of facet development. Sharp cusps usually indicate browsers, rounded cusps suggest mixed feeders, and blunt cusps tend to represent grazers. The space between the cusps is recorded as being either high or low and indicates a browser or grazer, respectively (Fortelius and Solunias, 2000).

Postcranium

The age, side, body size class (BSC), and degree of completeness were documented for each bovid element. The body mass of a BSC I bovid is <23 kg., BSC II 23-84 kg., BSC III 84-296 kg., and BSC IV> 296 kg ( Brain, 1981). The skeletal part representation was determined by analyzing the number of identified specimens (NISP) for each element, the minimum number of elements (MNE) those specimens comprise, and the comprehensive minimum number of individuals (cMNI) they encompass while considering factors such as age, side, size, and sex, a method outlined by Bunn (1982). The postcranial elements were compared with bovid long bone data presented in Scott (1985) and Swanepoel and Steyn (2011).

The limb bones were examined systematically for the identification of any pre, peri, or postmortem taphonomic processes. Specifically, the surface modification and fracture pattern were documented for each bone. The surface modification options outlined by Behrensmeyer (1978) and White (1992) include: cut marks, hammerstone percussion, cortical peeling, pathology, punctuate depressions, root etching, scooping or hollowing, gastric etching, tooth notches, tooth pitting, tooth scoring, carnivore damage, cracks, trowel damage, sedimentary abrasion, and evidence of being scooped/ hollowed, eroded, chewed, crushed, flattened, rotted, burnt, or gnawed by rodents or porcupines. This analysis aids in identifying what, if any, biotic or abiotic agents played a role in the accumulation of the assemblage.

Finally, the breakage patterns of the bones as defined by Villa and Mahieu (1991) were recorded for each specimen. These patterns include the fracture angle, fracture outline, shaft circumference, and degree of shaft fragment completeness. Villa and Mahieu (1991) describe the fracture angle as the angle exhibited by the fracture surface and the bone cortical surface. These breakages fall into one of three descriptive categories: oblique, right, and intermediate. Oblique fracture angles, defined as obtuse or acute, are indicative of green, perimortem fractures while right angled fractures suggest dry, post depositional breakages. The fracture outline involves the shape of the broken bone edge and also includes three separate categories: transverse, curved, and intermediate. Transverse breakages are perpendicular to the shaft of the bone and associated with post depositional processes. Curved breakages refer to spiral or partially spiral fractures, represent “complex, multidimensional morphologies,” and usually associated with perimortem fractures with some exceptions ( Villa and Mahieu, 1991). Specifically, several analysts highlight how postmortem spiral fractures can result from weathering, carnivore damage, and hominin percussion ( Haynes, 1983; Villa and Mahieu, 1991; White, 1992). The shaft circumference involves diagnosing how complete the bone circumference is (¼, ½, ¾, or 1) at any point along that bone fragment. Complete circumferences suggest in situ, postmortem breakages while less complete shaft circumferences tend to signify perimortem fractures. These fractures help identify whether carnivores manipulated the assemblage by attacking limb bone epiphyses and by leaving behind the diaphyses with complete circumferences. Less complete shaft circumferences can be indicative of fractures at the time of death, hominin manipulation, and/or abiotic processes such as sediment compaction. The degree of shaft completeness refers to what percentage of the entire bone remains. Complete or mostly complete bones suggest that little to no modification affected the bone prior to deposition. This research expands on Val et al. (2015), which included a taphonomic analysis of the entire vertebrate assemblage of Malapa. This paper provides complimentary taphonomic analyses that focus solely on specimens in the

Family Bovidae . The specific results provided in this paper provide a more in depth analysis of the bovids, which are comparable with the more general results of the entire assemblage from Val et al. (2015).