SEARCH

SEARCH BY CITATION

Keywords:

  • cave bear;
  • cranium;
  • Pleistocene;
  • Poland

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusions
  8. Acknowledgements
  9. References

A cranium of a young female cave bear (Ursus spelaeus R.) was found in the Upper Pleistocene sediments of Bear Cave in Kletno, SW Poland. A detailed analysis of the cranium, including radiology, CT and histological methods, revealed numerous pathological changes caused both by diseases and by injuries inflicted by another predator. It is likely that during its lifespan, the young female was exposed to several attacks (bites on the head) from adult bears. The injuries varied in extent and caused bone infection and inflammation. The nature of most of them suggests that they were not fatal but could have had a significant effect on the overall fitness of the animal. In contrast, the lesions on the frontal bone and in the anterior part of the parietal bone may have been the cause of the individual's death. Additionally, the cranium was found to have cut marks, sharp-edged longitudinal scars that indicate the use of a sharp-edged tool, and are usually interpreted as effects of skinning. The finding is suggested to be indirect evidence of the existence of people in southern Poland during the Pleistocene. Copyright © 2012 John Wiley & Sons, Ltd.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusions
  8. Acknowledgements
  9. References

The cave bear (Ursus spelaeus Rosenmüller and Heinroth, 1778) was one of the most characteristic large carnivores of the Upper Pleistocene. In Europe, it co-occurred with other animals and with the ancestors of contemporary humans (Kurtén, 1995; Münzel et al., 2001; Münzel, 2002; Münzel & Conard, 2004; Wojtal, 2007). As with modern bears, Pleistocene animals hibernated, and the natural deaths that sometimes occurred during this season behaviour have resulted in numerous accumulations of bones within caves. This large body of skeletal remains facilitates palaeopathological studies (Capasso, 1998). It is known that the animals suffered from many diseases, and their traces can be analysed on the basis of their bones. The pathologies included injuries (Pales, 1930; Abel & Kyrle, 1931; Ehrenberg, 1931; Wiszniowska, 1976), inflammatory changes (Cadeo, 1955; Wiszniowska, 1976; Wiszniowska et al., 1998; Lasota-Moskalewska, 2008), tumours (Esper, 1774; Pales, 1958; Nowakowski, 2008) and developmental anomalies (Stiner, 1998). All such pathological changes are known in the present day as well in the fossil record, but their exact interpretation is still difficult and debatable.

Palaeontological literature includes descriptions of pathological cases of cave bear skulls (Esper, 1774; Capasso, 1998). Kurtén (1995) thought that the lesions are usually of traumatic origin and may be associated with head injuries as a result of contact with the low and sharp ceiling of the caves which the bear inhabited periodically. According to another hypothesis, the skull lesions might be the effect of attack of another predator or perhaps a human hunter (Kubacska, 1930). Irrespective of the origin of the injuries, they leave traces on the bones, often in the form of spreading inflammatory process or healing scars. Ascertaining of the causes of such lesions is very difficult and requires the use of an array of diagnostic methods and differentiation.

The case of the skull of U. spelaeus from Poland, described later, documents all the aforementioned causes of lesions. It is also unique in that it appears to exhibit cut marks, perhaps from injuries inflicted by humans.

Materials and methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusions
  8. Acknowledgements
  9. References

The specimen, found in the deposits of Cave Bear in Kletno, SW Poland, is archived in the collection of the Palaeozoology Department, Wrocław University. It consists of an incomplete calotte, with partly preserved and post mortem damaged frontal, parietal and occipital bones (Figure 1). The preserved fragment has the maximum length of 29 cm and a width at postorbital process of 12 cm. On the basis of the analysis of size and the angle of inclination of the frontal bone, the skull belonged to a young female cave bear (Koby, 1953; Kurtén, 1955; Wiszniowska, 1976). The bone remains from Bear Cave were originally dated as 20 000 to 13 000 years bp (Wiszniowska et al., 1998), but recent results indicate an older age: radiocarbon dating of cave bear remains from different profiles from Bear Cave have given ages from 32 100 ± 1300 to >49 000 years bp (Bieroński et al., 2009). All the dates correspond to the period MIS 3, from the Grudziądz Interstadial to the main stadial of the Vistula glaciation (LGM).

image

Figure 1. Skull of Ursus spelaeus R. from Kletno, Poland, right parietal–frontal view. This figure is available in colour online at wileyonlinelibrary.com/journal/oa.

Download figure to PowerPoint

The lesions that were visible on the skull were subject to analysis with many mutually supplementing methods. The lesions on the external surface of the bone and the bone structures visible inside the skull were subject to macroscopic analysis. X-ray photos were taken with digital technique (focus-object distance 1 m) in norma verticalis, norma lateralis and norma frontalis. CT analysis was performed in frontal plane, scanning the object every 0.5 cm.

A fragment of bone tissues from the inflammatorily changed right parietal bone on the side of lamina interna was histologically examined as a bone section in light microscope [embedded in Epon Sigma-Aldrich Chemie GmbH and stained with haematoxylin and (Aqua-Med ZPAM-Kolasa, Poland eosin)].

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusions
  8. Acknowledgements
  9. References

The preserved fragment of the skull shows an array of lesions. The anterior part of the right parietal bone bears an extensive concave area with gentle edges and diameter of about 3.5 cm. The character of the lesion indicates injury and bone tissue reconstruction. Numerous bone fistulae are visible within the area [Figure 2(A)]. A changed surface of the external lamella that is slightly concave can be seen in the posterior part of the bone, in the region of lambdoid suture. Unfortunately, the adjacent fragment has been mechanically broken off.The posterior part of the left parietal, on the lateral edge of sagittal crest, bears two oval concavities (diameter ~1 and 0.5 cm) with gentle edges reaching ~1 cm deep. The bone tissue in the area is porous [Figure 2(B)].

image

Figure 2. Details of the skull lesions: (A) lesions on the right parietal bone; (B) lesions on the left parietal bone, on sagittal crest; (C) hole in the frontal bone; (D) longitudinal scars of the frontal bone. This figure is available in colour online at wileyonlinelibrary.com/journal/oa.

Download figure to PowerPoint

A hole of ~1 cm diameter is situated in the middle part of the external lamella of the frontal bone, on its right side in the sagittal axis [Figure 2(C)]. The hole is oval, and its edges gently descend towards the centre, with a visible layer of callus. The location of the edge of the hole is ~2 mm lower than that of the internal lamella.

Five longitudinal scars on the bone tissue are visible in the middle part of the frontal bone [Figure 2(D)]. They are 1.5 to 4.2 cm long, up to 1 mm wide and a few millimetres deep. Their edges are blunt but well visible. They are located at various angles but mostly at an angle of up to 40° to the sagittal suture.

The X-ray image shows an array of changes in the structure of bone tissue [Figure 3(A, B)]. The analysis of the image is rendered difficult by the extensive post mortem damages to the skull and the superimposed shadows of the sinuses, which are well developed in U. spelaeus (Koby, 1949). The image of the extensive pathology on the right parietal bone is characterised by chaotic changes in the saturation of X-ray shadow without visible borders [Figure 3(A, B arrow a)]. Similar changes, but with a distinct border in the form of increased saturation of X-ray shadow, are visible also in the posterior part of this bone [Figure 3(A and B, arrow b)]. The two areas of damage of bone tissue visible below the sagittal crest show distinct borders, but there is no visible increase in density of the bone tissue on their borders [Figure 3(A, arrows c)]. The oval hole in the bone tissue of the frontale is surrounded by an area (~2 mm) of increased density [Figure 3(B, arrow d)]. The long axis of the hole is at an angle of ~8° to the skull axis. The delicate changes of the bone tissue, which are visible in X-ray in Figure 3(B, arrow e), have the form of longitudinal areas, ~1 mm wide, of tissue with decreased bone density and visible calluses on the sides.

image

Figure 3. Skull X-ray and CT images: (A) X-ray in lateral view; (B) X-ray in antero-posterior view; (C, D) CT in frontal plane.

Download figure to PowerPoint

The analysis of computer tomography image in frontal plane reveals a rounded area of pathologically changed bone tissue of irregular structure at the level of the centre of bone lesion on the right parietal bone [Figure 3(C)]. A thin sclerotic line delimits the lesion on the side of internal lamella of the bone, whereas near the cerebral part there is no distinct boundary and the changed tissue infiltrates the cerebral region [Figure 3(C, arrow)]. Consecutive CT layers show that the axis of the concavity and the accompanying change in the structure of bone tissue are perpendicular to the parietal bone lamella. CT scans [Figure 3(D)] corresponding to the longitudinal scars of the frontal bone tissue [Figure 2(D)] show cracks, the lack of continuity of the tissue, running obliquely between the external and internal lamellae of the frontal bone. The bone shadow on the boundaries of these cracks is more saturated [Figure 3(D, arrow)].

The histological image of the pathologically changed region shows a changed structure of bone tissue in the form of irregularly arranged osteons of varied diameter [Figure 4(A)]. Bone mineralisation is well visible in polarised light; the laminae are chaotically arranged and intertwined [Figure 4(B)]. Areas of aggregated osteocyte lacunae and chaotically arranged bone lamellae on the periphery are visible, with areas of bone tissue resorption [Figure 4(C, arrows)].

image

Figure 4. Histological section in transmitted light: (A) irregularly arranged osteons of varied diameter, aggregates of osteons (osteocyte lacunae); (B) same section in transmitted polarised light; (C) bone tissue resorption (arrows). This figure is available in colour online at wileyonlinelibrary.com/journal/oa.

Download figure to PowerPoint

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusions
  8. Acknowledgements
  9. References

The described skull fragment from Bear Cave is another example of pathological changes of skulls of U. spelaeus. Like those described by Capasso (1998), the case shows a great number of lesions, and their etiological interpretation is uncertain. However, here, the lesions involve most of all the region of the right parietal bone and the frontal bone, and are of more varied character.

The character of lesions on the parietal bones, visible through morphological, radiological and histological analyses, resembles the effect of an expanding abscess. The characters of these lesions indicate that the injuries occurred in various periods of the individual's life and with varied intensity. The scar on the posterior edge of the crest seems to be the least significant of the described lesions [Figure 2(B)], as its extent is rather small. The absence of bone remodelling around the holes [Figure 3(A, arrow c)] suggests that the pathological process was short-lasting and occurred at the end of the bear's life. A much more extensive inflammation is visible on the posterior part of the right parietal bone [Figure 2(A)], but its character can only be analysed precisely through the X-ray images [Figure 3(B, arrow b)]. On such images, the radially spreading bone tissue shadow is visible, and the sharp border indicates that the inflammatory process has ended. The lesions on the posterior part of the right parietal bone are very difficult to analyse, as the region shows extensive mechanical damage. However, the radiological image [Figure 3(A, B, arrow b)] suggests an extensive inflammatory process caused by an abscess that had healed before the animal died. No doubt, the greatest post-inflammatory lesion is the one found on the right parietal bone. The bone shows an extensive area of bone tissue reconstruction. Both the X-ray image [Figure 3(A, B)] and CT [Figure 3(C)] as well as histological analysis [Figure 4(A–C)] show a great disturbance in the organisation of the bone tissue. The irregular arrangement of the lamellae and the osteocyte aggregates testify to a lasting inflammatory process. The process was of long duration as indicated by the sclerotic lines visible on the CT. The presence of highly mineralised bone tissue [Figure 4(B)] shows that the repair process has started.

Osteitis, periostitis and osteomyelitis are caused by microorganism invasion and development in the bone. These three terms indicate the extent of infection, from a limited subperiosteal reaction to the one including the whole bone. The bacteria spread as a result of direct injury to the bone, infection of the neighbouring tissues or through blood circulation. The infection can be very limited or it may spread to the entire skeleton (Brothwell, 2008).

The CT analysis of the described lesion shows that the inflammatory process spread toward the brain [Figure 3(C, arrow)]. This probably caused a subarachnoid infection and was the direct cause of death.

Although osteological evidence of infection (usually as a result of injury) is not uncommon (Rothschild & Martin, 1993), the infection-causing microorganisms cannot be specified precisely. The possibility that the changes are a result of ostitis should also be considered: Koby (1953) described a cave bear skull with osteolytic changes, which were interpreted as resulting from infection caused by sinuses parasites. Additionally, the extent of changes and their intensity do not allow for unambiguous identification of the injury cause. A bite inflicted by another predator is possible, but the position of the scar axis would seem to exclude this. Probably the vector of the object that inflicted the injury was perpendicular to the bone surface, and the object was a stone dropping from the roof of the cave. It is debatable if the low roof the caves that were temporarily inhabited by the bears could be the reason for skull injuries. Some authors suggest that such injuries were associated with the fact that the animals lived in caves and moved in chambers with rough walls and low ceilings (Kurtén, 1995). The view, first presented by Pales (1958) and considered also by Capasso (1998), should be verified. Rock fragments falling from the ceiling seem to be much more likely causes of injuries. The bears, being animals that periodically stayed close to cave entrances, where still some daylight is available, stayed in places where the geological conditions, for example, changes in the rock tension, were associated with, for example, the temperature changes on the turn of seasons. In such conditions, falling rocks could cause injuries to bears in their lairs. Such injuries were more likely in the case of adult animals, as young bears would be protected by their mother's body while in the cave.

The hole in the frontal bone originated when the animal was alive, and initial stages of healing are visible. This is indicated by the callus around the hole [Figure 2(C)] and the sclerotic area around the scar, which is visible on the X-ray image [Figure 3(A, arrow d)]. On the basis of the analysis of the shape of the scar and the angle of its axis, it can be supposed that it is the remains of a very strong bite from the canine of another carnivore. Similar skull injuries, which are described in the palaeontological literature (Moodie, 1923; Miller, 1980), are most likely caused by the fighting behaviour observed in modern bears (Erdbrink, 1953). Attacks by adult males, which kill juveniles by biting their skulls, are especially frequent (Matheson, 1942; Vaisfeld & Chestin, 1994). Aggressive interactions between cave bear and cave lion are also possible. Remains of these Pleistocene species have been found in European caves (Guerin & Patou-Mathis, 1996). The skull is unique in the sense that it is the only one among the several dozen cave bear skulls found in Bear Cave that appears to demonstrate cut marks. Their size, arrangement and depth visible on the CT suggest that they result from several blows with a sharp-edged object. In criminological literature, such injuries are described as results of purposeful blows with an axe, spade or another sharp-edged tool applied at different angles (Kimmerle & Baraybar, 2008; Pickering & Bachman, 2009). In archaeology, such scars are interpreted as effects of the use of a blade during skinning (Lasota-Moskalewska, 2008). The blurred edges of the external lamellae and sclerotic lines, which are visible on the X-ray [Figure 3(B, arrow e)] and CT images [Figure 3(D, arrow)], prove that the animal has survived the blows.

Despite the suggestions that the Palaeolithic humans and cave bear used different ecological niches and the chances of their encounter were limited (Koby, 1954), a meeting of the two species was possible (Stiner, 1998). The coexistence of Palaeolithic humans and the cave bear in Central Europe is supported by a substantial body of evidence; some of it directly indicates hunting of bear by humans (Münzel et al., 2001; Münzel, 2002; Münzel & Conard, 2004; Wojtal, 2007). Possibilities of human–bear encounters were also discussed by Abel & Kyrle (1931) for Mixnitz Cave where six out of the thousands of examined injured skulls came from that cave. Wankel (1892), in his description of a skull from Sloup Cave (Moravia), suggested that the flint tools found nearby support the possibility that the skull scars may be a result of human activities. It is thus possible that the cut marks on the described skull are remains of an encounter with a human who attacked but failed to kill the bear.

No direct evidence of occupancy by primitive humans has been found in the Polish part of the Sudetes, but such humans could temporarily stay in the region, having come from across the southern part of the Sudetic Massif (Wiszniowska, 1976). A human–bear encounter on the northern part of the Sudetes is thus not excluded.

Conclusions

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusions
  8. Acknowledgements
  9. References

The described skull shows very varied and extensive pathological changes. The lesions originate from various periods of the animal's life. Some of them were of no great significance, but most undoubtedly affected the bear's condition in a negative way and could be the reason for its death. The analysis suggests that the young female bear, in her short life, had many unfortunate accidents, which could increase the probability of further injuries. The bear, weakened by numerous inflamed injuries that occurred in the cave, could have met people whose attack she survived. The bear also survived an attack from another carnivore, perhaps an adult bear. Having only the skull fragment at our disposal, we could not analyse the possible lesions of other parts of the skeleton. It is also difficult to specify the cause of death, but it seems likely that the abscess in the region of the right parietal bone and the inflammation extending to the brain were the reasons. It is noteworthy that the described case may be an indirect evidence for the presence of man in southern Poland in the Upper Pleistocene.

Acknowledgements

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusions
  8. Acknowledgements
  9. References

We appreciate the constructive comments and critical evaluation of I. Hershkovitz, Department of Anatomy and Anthropology Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel, and as well as the linguistic assistance of B. M. Pokryszko, Museum of Natural History, Wrocław University, Poland.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Results
  6. Discussion
  7. Conclusions
  8. Acknowledgements
  9. References
  • Abel O, Kyrle G. 1931. Die Drachenhöhle bei Mixnitz. Spelaeological Monographs Volumes 78,: Vienna.
  • Bieroński J, Stefaniak K, Hercman H, Socha P, Nadachowski A. 2009. Palaeogeographic and palaeoecological analysis of sediments of the Niedźwiedzia Cave in Kletno. Karst of the Częstochowa Upland and of the Eastern Sudetes: Palaeoenvironments and Protection Studies of the Faculty of Earth Sciences, K Stefaniak, P Socha (eds.). University of Silesia: Sosnowiec–Wrocław; 401422.
  • Brothwell DR. 2008. Paleoradiology in the service of zoopaleopathology. Paleoradiology—Imaging Mummies and Fossils, RK Chhem, DR Brothwell (eds.). Springer: Berlin, Heidelberg, New York; 119145.
  • Cadeo GC. 1955. L' Ursus spelaeus Rosenmüller & Heinroth del Buco del Piombo sopra Erba (Prealpi Comasche). Atti della Societa Italiana di Scienze Naturali presso il Museo Civico di Storia Naturale di Milano 94: 5556.
  • Capasso L. 1998. Cranial Pathology of Ursus spelaeus Rosenmüller & Heinroth from Chateau Pignon, Basque Territories (Spain). International Journal of Osteoarchaeology 8: 107115.
  • Ehrenberg K. 1931. Der Höhlenbär. Aus der Heimat 44: 6580.
  • Erdbrink DP. 1953. Review of Fossil and Recent Bears of the Old World, with remarks on their phylogeny, Volume 2. Deventer.
  • Esper JF. 1774. Aus führliche Nachricht von Neventdeckten Zoolithen Unbekannter Vierfüssinger Thiere. Nürnberg.
  • Guerin C, Patou-Mathis M. 1996. Les Grands Mammiferes Plio–Pleistocenes d'Europe. Masson: Paris; 205208.
  • Kimmerle EH, Baraybar JP. 2008. Skeletal Trauma. CRC Press Taylor and Frances Group: Boca Raton, Florida.
  • Koby FE. 1949. Le dimorphisme sexuel des canines d'Ursus arctos et d'Ursus spelaeus. Revue Suisse de Zoologie 56: 675687.
  • Koby FE. 1953. Lesions pathologique aux sinus frontaux d'un ours des cavernes. Eclogae Geologicae Helvetiae 46: 295297.
  • Koby FE. 1954. Les paleolithiques ont-ils chasse l'orsus des carvernes? Actes de la Societe Jurassienne d'Emulations: 148.
  • Kubacska A. 1930. Pathologische untersuchungen an ungarlandischen Versteinerungen. Palaeobiologica 3: 365370.
  • Kurtén B. 1955. Sex dimorphism and size trend in the cave bear, Ursus spelaeus Rosenmüller & Heinroth. Acta Zoologica Fennica 90: 148.
  • Kurtén B. 1995. The Cave Bear Story: Life and Death of a Vanished Animal. Columbia University Press: New York.
  • Lasota-Moskalewska A. 2008. Archeozoologia–Ssaki. Wydawnictwa Uniwersytetu Warszawskiego: Warszawa.
  • Matheson C. 1942. Man and bear in Europe. Antiquity 142: 151159.
  • Miller GJ. 1980. Some new evidence in support of the stabbing hypothesis for Smilodon californicus Bovard. Carnivore 3(2): 826.
  • Moodie RL. 1923. Paleopathology—An Introduction to the Study of Ancient Evidences of Disease. University of Illinois Press: Urbana.
  • Münzel SC. 2002. Cave bear hunting on the Swabian Alb (Germany), 30.000 years ago. In Cave–Bear–Researches, Höhlen–Bären–Forschungen, Rosendahl W, Morgan M, López M, Correa M (ed.). Abhandlungen zur Karst und Höhlenkunde 34: 36–39.
  • Münzel SC, Conard NJ. 2004. Change and continuity in subsistence during the Middle and Upper Palaeolithic in the Ach Valley of Swabia (South-west Germany). International Journal of Osteoarchaeology 14: 225243.
  • Münzel SC, Langguth K, Conard NJ, Uerpmann HP. 2001. Höhlenbärenjagd auf der schwäbischen alb vor 30.000 jahren. Archäologisches Korrespondenzblatt 31/3: 317328.
  • Nowakowski D. 2008. Selected problems of paleopathology from the Quaternary deposits of cave bear (Ursus spelaeus) from Jaskinia Niedźwiedzia (Bear Cave) in Kletno, Poland. Archaeozoological research in Poland and Middle-East Europe. Data–methods–interpretation, D Makowiecki (ed.). Bogucki Wydawnictwo Naukowe: Poznan; 7980.
  • Pales L. 1930. Paléopathologie et Pathologie Comparative. Masson: Paris.
  • Pales L. 1958. Pathologie de l'Orsus des cavernes. Annales de Paleontologie 44: 344.
  • Pickering RB, Bachman D. 2009. The use of forensic anthropology. CRC Press Taylor and Frances Group: Boca Raton, Florida.
  • Rothschild BM, Martin LD. 1993. Paleopathology—Disease in the Fossil Record. CRC Press Taylor and Frances Group: Boca Raton, Florida.
  • Stiner MC. 1998. Mortality analysis of Pleistocene bears and its paleoanthropological relevance. Journal of Human Evolution 34: 303326.
  • Vaisfeld MA, Chestin IE. 1994. Bears: Brown Bear, Polar Bear, Asian Black Bear. Nauka: Moscow.
  • Wankel J. 1892. Die praehistorische Jagd in Mähren. Kramár and Procházka: Olmütz.
  • Wiszniowska T. 1976. Niedźwiedź jaskiniowy z Kletna i innych jaskiń Polski. Jaskinia Niedźwiedzia w Kletnie. Acta Universitas Wratislaviensis: Wrocław.
  • Wiszniowska T, Kuryszko J, Nowakowski D. 1998. Micromorphologic analysis of bony relicts of Cave Bear (Ursus spelaeus, Rosenmuler, 1778). Animal relicts as the scientific material on the differentiation of the economical and cultural life of humans throughout the varius historical periods. Wydział Medycyny Weterynaryjnej Akademii Rolniczej we Wrocławiu: Wroclaw; 4248.
  • Wojtal P. 2007. Zooarchaeological studies of the Late Pleistocene sites in Poland. Institute of Systematics and Evolution of Animals. Polish Academy of Science: Kraków.