Description
Changes of the cranio-dental morphology of spotted hyaena (Crocuta crocuta, Erxleben 1777) in Britain from the early Middle Pleistocene to Marine Oxygen Isotope Stage 3Jones, A., Schreve, D. and Carbone, C.
Currently restricted to sub-Saharan Africa, spotted hyaenas (Crocuta crocuta) had a widespread distribution in Eurasia during the Pleistocene. Within Britain, their remains have been found in deposits attributed to the early Middle Pleistocene, and Marine Oxygen Isotope stages (MIS) 9, 7, 5e, 5c and 3, after which point C. crocuta became locally extinct. During this period, they experienced diverse environmental pressures, including changes in climate, vegetation, competition, and prey species. One way in which mammals frequently respond to environmental fluctuation is through changes in body size and shape. This study focuses on cranio-dental morphological changes of British fossil C. crocuta, using linear measurements to establish the degree of ecophenotypic change present and the possible drivers behind this. Recent body mass data of C. crocuta across Africa were drawn from the literature. Corresponding present-day environmental data were also sourced from the literature and the influences of these variables upon modern body mass were assessed. These results aided interpretation of the fossil data. It is hypothesised that C. crocuta body size increases with cooler conditions. The largest Pleistocene specimens are therefore predicted to be from MIS 3.
The Pleistocene results indicate that (i) teeth from MIS 9 are smallest, those from MIS 7 are often the largest, and the early Middle Pleistocene teeth plot within the range of the Late Pleistocene samples, (ii) C. crocuta from MIS 3 are more clearly distinguished from those of MIS 5e and 5c age in the size of the lower than the upper dentition, (iii) where distinctions are made, teeth from MIS 3 are often significantly larger than those from MIS 5e and 5c, except for the lower 2nd premolar, where the relationship is reversed, (iv) where available, the mandibular measurements generally do not show clear differentiation in size between different periods in the Pleistocene.
Although sample sizes were small, the results of the modern study suggest that temperature, distance from the equator and precipitation are the variables that are most strongly correlated with C. crocuta body mass. Contrary to the hypothesis, the results suggest that body size increases with warmer temperatures. Therefore, where the fossil cranio-dental measurements reflect overall body size, they were potentially influenced by a combination of temperature and precipitation changes through the Pleistocene.
Poster presentation
| Period | 23 Aug 2017 → 26 Aug 2017 |
|---|---|
| Event type | Conference |
| Location | Calgary, CanadaShow on map |