CEE Seminar, Weds 23 May at 5pm: Title: ‘Reconstruction of diet in extinct mammals –Methods, limits, and a case study: the cave bear Ursus spelaeus’

Please note the following GEE/CEE Seminar taking on Weds 23 May at 5pm

Venue:  UCL AV Hill LT.

All are welcome.

Speaker: Stephane Peigne,  Museum National d'Histoire Naturelle, Paris

Web: http://www2.mnhn.fr/hdt203/info/peigne.php

Host: Anjali Goswami

 

Title: ‘Reconstruction of diet in extinct mammals –Methods, limits, and a case study: the cave bear Ursus spelaeus’

Diet is an important trait of the ecology of organisms that is fundamental to study trophic interaction in a food web. In extinct animals also, this is one of the most frequently reconstructed traits. For palaeontologists, reconstructing the diet of an extinct species serves as a basis of discussion or for inferences on, e.g., its trophic relationships, the reasons of its evolutionary success or extinction, etc. However, estimated diet can be biased as a result of sampling or methodologies and this bias obviously is more pronounced for extinct than for extant organisms. As a paleontologist, I frequently investigate dietary preferences of extinct carnivorous mammals, my studied group. As many colleagues, I base my work almost exclusively on data obtained from extant relatives of species or families under study.

After shortly reviewing several methods to reconstruct the diet of extinct mammals, I will present a case study, the diet of the cave bear Ursus spelaeus. The diet of cave bears was greatly debated, although most previous morphological and isotopic studies indicate that cave bear diet was mostly vegetarian. This result is surprising given energetic constraints for an animal that reached the size of the largest extant brown bears. With the great progress of the nutritional ecology in the last decades, ecologists have now a large amount of data on the nutritional ecology of brown bears. Given this knowledge, it is quite difficult, at least for me and some other colleagues, to believe that cave bears may rely mainly on vegetarian matter. For this reason, we then decided to re-investigate the cave bear diet and to test the vegetarian hypothesis by using dental microwear analysis on an archeological, well-dated sample of individuals from several horizons of a Belgian cave. Our results demonstrate that cave bears were not strictly vegetarian, especially before dormancy, but that they had a mixed diet including a large array of food items. This result also indicates that studies only based on multiple approaches (morphology, geochemistry, dental microwear analysis) may provide a rather complete knowledge of the biology of an extinct species.