FACULTY OF SCIENCES Palaeontology Department Biology Department Academic year 2009-2010 The fossil cave hyena of Goyet, Walsin and Hastière (Belgium): osteometry and taphonomy Debora Beke Thesis submitted to obtain the degree of Master in Biology Supervisor: Prof. Dr. J. Verniers Supervisor and tutor: Dr. M. Germonpré (RBINS) © May 2010 Faculty of Sciences – Biology Department All rights reserved. No part of the publication may be reproduced in any form by print, photo print, microfilm, electronic or any other means without written permission from the publisher. Table of contents 1. INTRODUCTION 1 1.1. General introduction 1 1.2. The spotted hyena - Crocuta crocuta 1 1.2.1. Recent spotted hyena 1 1.2.2. Fossil spotted hyena or cave hyena 2 2. AIMS 2 3. MATERIAL AND METHODS 3 3.1 Description of the sites 3 3.2 Description and organisation of the material 6 3.3 Methods and measurements 6 3.3.1 Cranial measurements 6 3.3.2 Postcranial measurements 8 3.3.3 Age determination 8 3.3.4 Weathering and gnawing traces 9 3.3.5 Database 9 3.3.6 Comparing fossil and recent spotted hyena 10 4. RESULTS 11 4.1. Inventory of the fossil material 11 4.2. Description of the fossil material 27 4.2.1. Cranial 27 4.2.2. Postcranial 38 4.3. Age determination 43 4.4. Trace fossils 45 4.4.1. Coprolites 45 4.4.2. Other traces 45 4.5. Weathering 47 4.6. Inventory of the recent material 48 4.7. Description of the recent material 50 4.7.1. Cranial 50 4.8. The fossil and recent spotted hyena 61 5. DISCUSSION 66 5.1. Taphonomy 66 5.2. Age determination – Use as communal dens? 68 5.3. Gnawing traces and cannibalism 70 5.4. Fossil and recent spotted hyena 71 6. CONCLUSIONS 72 7. DUTCH SUMMARY 73 8. THANKS 75 9. REFERENCES 76 ANNEXES 79 Alphabetical List of abbreviations 79 Statistical tests CD-Rom Primary data CD-Rom 1. INTRODUCTION 1.1 General introduction In Belgium many local deposits of Late Pleistocene fossil mammals are found in the Flemish Valley: a complex of valleys eroded and refilled by the activity of rivers estuaries and eolian action (GERMONPRÉ, 1995 and 1996). In the Ardennes, fossil mammals are very well represented in caves along the Meuse River (GERMONPRÉ, 1995, 1996). In this research we present the osteometric and taphonomic characteristics of bone assemblages from the fossil spotted hyena found in three caves: the Goyet cave, ‘Trou de l’hyène’ (Walsin) and the Hastière cave. These three caves situated in Namur province, were excavated by Dupont between 1860 and 1872. Dr. Germonpré, associated with the Palaeontology department of the Royal Belgian Institute for Natural Sciences (RBINS), has already done research on the Goyet cave. Studying hyena taphonomy can be of great importance for paleontological research as hyenas produce large osseous assemblages (POKINES & PETERHANS, 2007). 1.2 The spotted hyena – Crocuta crocuta 1.2.1 The recent spotted hyena Recent spotted hyenas are found in the sub-Saharan region of Africa and are distinguished by their exceptionally enlarged premolars, robust skulls and teeth (BINDER & VALKENBURGH, 2000). They live in social groups (clans) of 5-90 members that recognize each other by sight, scent and vocalisation. Adult females, cubs and immigrant adult males live together (KRUUK, 1972; HOLEKAMP & SMALE, 1998). Adult females bear litters of one or two cubs, born in isolated natal dens with fully opened eyes and fully erupted canine and incisor teeth. After three to four weeks the cubs are brought to a communal den where all cubs live together until they are eight to nine months old. After this period, they leave the communal den and start to explore the world outside; sometime later weaning starts. Eventually they will reach adult and reproductive maturity (at 24 months for males, at 36 months for females) (KRUUK, 1972; HOLEKAMP & SMALE, 1998). Holekamp and Smale (1998) described this hyena life through five developmental stages; each starting and ending at a specific age and characterized by important moments in life. Cannibalism among spotted hyenas is a controversial issue. According to Kurtén (1968) spotted hyenas are not intentional cannibals as eyewitnesses state that hyenas do not eat other hyenas. Kruuk (1972) on the contrary states that protection against other hyenas is a necessary behaviour pattern and that hyenas kill and eat almost everything, including members of its own clan. He proposes that this is one of the reasons why females are bigger than males: to keep the latter away from the cubs. Also the ability of the cubs to creep out of reach of the adults may be a protection against cannibalism, as well as the fact that females always keep their litters in close proximity to each other so that cubs are protected when some mothers are away. 1 1.2.2 The fossil spotted hyena or cave hyena During the Pleistocene, the cave hyena was widespread in Eurasia and is therefore represented in many European bone caves. These caves were often used as dens (KURTÉN, 1986; KLEIN & SCOTT, 1989). Cave hyenas are distinguished from the now living African spotted hyenas mainly by size and limb proportions. They were carnivores with powerful bone cracking teeth with carnassials forming an effective shearing device; the canines were relatively feeble (KURTÉN, 1965, 1986). The cave hyena is described by many authors as a subspecies of the spotted hyena (Crocuta crocuta spelea). Rohland et al. (2005) did a DNA-analysis on Pleistocene and recent spotted hyenas and came to the conclusion that the sequences of both clades are intermixed, which suggest that both clades are not monophyletic. Furthermore, there were at least three migrations of African spotted hyenas to Europe and Asia around 3, 1 and 0 MYA. These last two migration events gave rise to the European populations (ROHLAND et al., 2005). At the end of the Ice Age, the cave hyena became extinct in Eurasia. As the cave hyena and recent spotted hyena are closely related, we can use our knowledge of the recent spotted hyenas to make interpretations about the way of life of cave hyenas. In general, we presume that their life was characterized by similar life strategies, that is, cubs are also raised in communal dens. 2. AIMS The fossil hyena material from the three different Belgian sites will be studied and measured in order to answer some questions. What kind of skeletal elements are found and which ones are lacking? Are there any marks present on the bones, like gnawing traces that could point to cannibalism? Do we find significant differences between the caves in the foregoing respects and why do we find differences? The main question is whether the hyenas used the caves as communal dens or whether they used them just as safe places to shelter. Do we find, besides adult bones, juvenile remains that can indicate the use of a cave as communal den? We also compare the fossil material of Crocuta crocuta with some recent material. This comparison may reveal significant differences between both groups. 2 3. MATERIAL AND METHODS 3.1 Description of the sites Goyet, Walsin and Hastière are situated in the Namur province in Belgium (fig. 3.1). Fig. 3.1: Location of Goyet, Walsin and Hastière. (2010 Google – Data 2010 Tele Atlas Europe Technologies, PPWK) GOYET Goyet is situated at the confluence of the rivers Samson and Strud. On the right bank of the Samson lies a limestone cliff which harbours a series of caves. Those caves were excavated by E. Dupont between 1868 and 1869. Dupont numbered the different caves, five in total. The hyena material from Goyet analysed in this study was found in the third cave. The location of this third cave is situated 15 m above the Samson, with its entrance to the southwest. The cave is very long and connected with the other caves trough a series of galleries (GERMONPRÉ, 1996, 2001). Dupont divided the cave in three parts: Chamber A, B and C (fig 3.1). Chamber A is about 25m deep and 5m wide; chamber B is connected with A through a small gallery and is about 10m in depth. Chamber C lies the furthest from the entrance (110-120 m) (GERMONPRÉ, 1996, 2001, 2004). 3 Dupont described five successive bone horizons in this third cave, each horizon separated by sterile ‘alluvial’ sediments. As mentioned in the introduction, Dr. Germonpré (1996, 2001, 2004) has already started to study the Pleistocene assemblages: Bones from horizon 1 were mostly found in chamber A. This horizon yielded remains from herbivores and carnivores, but also a few human bones (Germonpré, 1997). In this horizon 1261 identified bones and 700 unidentified remains were counted (Germonpré, 2001). On several bones from this horizon AMS dating was done; the uncalibrated ages are listed in table 5.1. The bones from the muskox and the horse were modified by prehistoric man (Germonpré, 1996, 1997, 2001). Species Calibrated Age (yr BP) muskox 12 620 +/- 90 horse 12 770 +/- 90 27 230 +/- 260 cave hyena 35 000 +/- 400 cave bear 38 770+1180-1030 Table 3.1: Uncalibrated ages from muskox, horse, cave hyena and cave bear; Goyet- horizon 1 (Germonpré, 1996, 2001). The cave bear and cave hyena bones were located deeper in the chamber and have another origin than the human modified bones of the muskox and the horse that were found at the entrance of the chamber. The different dates of the hyena bones point to the mixed nature of the horizon (Germonpré, 1996, 2001, 2004). Horizon 2 of Goyet is also found in chamber A; a total of 1706 identified bones and several hundred unnumbered remains were collected.