Cave bear
| Cave bear | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Cave bear skeleton in the sleeping position in the Sophienhöhle |
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| Temporal occurrence | ||||||||||||
| Pleistocene | ||||||||||||
| 400,000 to about 28,000 years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Ursus spelaeus | ||||||||||||
| Rosenmüller , 1794 |
The cave bear ( Ursus spelaeus ) is an extinct bear species from the last glacial period . Its ancestral form is probably Ursus deningeri . The term cave bear refers to the location of fossil bones; However, it is misleading insofar as , according to current research , Ursus spelaeus only stayed in caves during hibernation . Due to this fact, the cave bear is called a so-called “cave-loving” animal.
Spread and appearance
The habitat of the cave bear was Europe, from northern Spain to the Urals . Its head-torso length was up to 3.5 m, its shoulder height about 1.70 m. It was therefore significantly larger than today's brown bear . As with today's bear species, the females of the cave bears were slightly smaller than the males ( sexual dimorphism ). The weight of a male cave bear is estimated at 600 to 1200 kg. This made male cave bears heavier than a bison or a Cape buffalo.
The cave bear had powerful jaws, the muscles of which were attached to a crest on the top of the head . Its large teeth and the relatively low content of nitrogen-15 in the collagen of the bear bones indicate, however, that it largely fed on plants. It was not a typical representative of the cold ages because, due to its eating habits, it was only spread as far as the northern border of deciduous trees and would not have found sufficient food in a tundra and cold steppe biotope.
For orientation in the almost complete darkness, the cave bear set scent marks by rubbing his fur on the cave walls. These discolored areas can still be seen today, for example, in the Hermannshöhle and Baumannshöhle in the Rübetal in the Harz Mountains.
Sites and extinctions
As in many other caves in Europe, bones ("Zooliths") have been found in the Zoolithenhöhle near Burggaillreuth in Franconian Switzerland since ancient times, which Johann Friedrich Esper examined more closely in 1771 and identified as bones, initially as those of polar bears, which the Flood washed up here. Esper described these finds in a large-format book in 1774, the first to be devoted to the subject of fossil bones alone. Only later was it recognized that it was not a polar bear or a brown bear , but a larger species of bear. The species description in the nomenclature of Linnaeus was carried out in 1794 by the physician Johann Christian Rosenmüller in his dissertation using a well-preserved skull from the same cave. It is unclear whether the skull described by Rosenmüller is today among the skulls that belong to the Rosenmüller collection and are kept in the Museum für Naturkunde in Berlin. The cave bear is the first extinct mammal species to be described according to the Linneischen system. Establishing it as a distinct species was a breakthrough for mammalian paleontology.
Despite the massive accumulation of bones and teeth in caves in the Franconian Alb , the Swabian Alb and Styria , the cave bear was not a cave dweller. The animals merely hibernated in the caves , so that even with the occasional death of one animal per cave during the tens of thousands of years of the Worm Ice Age , large accumulations of bones and teeth occurred. They are often well preserved in the basic environment of the Devonian , Permian or Jurassic limestone in the karst caves . Since the bones of the cave bears sometimes make up up to 90 percent of all bones found in a cave, a number of caves are named Bärenhöhle , Bärenloch , Drachenhöhle or Unicorn Cave .
From individual bones of different individuals compound cave bear skeletons are, for example, in the Baumannshöhle at Rübeland in the resin , the Devil's Cave and the Heinrichshöhle in Hemer issued. The German cave museum in Westphalia Iserlohn -Letmathe owns the nearly complete skeleton of the Dechenhöhle bullock found. In the Drachenhöhle near Mixnitz ( Styria ), the bones of around 3,000 individuals were uncovered, whose age was determined to be 30,000–40,000 years. One of the most complete skeletons is exhibited in the Sophienhöhle in a sleeping position in a bear bed.
To what extent cave bears were hunted by Ice Age hunters is still largely unclear. The only direct evidence is a projectile tip in the thoracic vertebra of a cave bear from the hollow rock near Schelklingen . The bone was found in archaeological settlement layers of the Gravettien (layer IIcf), which with 14 C dates was dated to about 29,000 BP . Cave bears were also depicted several times in the cave paintings of prehistoric man in southern France . Although the research-historical term bear cult is now considered an archaeological construct, exposed bear skulls have been found in some caves (for example in the Chauvet Cave ).
Currently, the latest direct radiocarbon data of this bear species is around 24,000 BP old, which corresponds to around 27,800 calendar years according to the current calibration . This period coincides with a cooling of the climate during the Ice Age (so-called Greenland Stage 3 ), which is why climate changes and a resulting change in vegetation - the basis of life for bears - are assumed to be the cause of the extinction . It is currently unclear whether the species survived longer in southern and eastern Europe.
The cave bear died out before the actual Quaternary extinction wave at the end of the Vistula or Worm Ice Age . The Cro-Magnon man of the Upper Palaeolithic as the cause of a strong decimation is also discussed ( overkill hypothesis ).
As researchers from the University of Zurich announced in August 2019, the population of cave bears in Europe fell sharply 40,000 years ago due to human influence. That was the time when modern man spread out here. Previously, the bear species had survived more than 400,000 years unscathed with several climate changes. For the study, the bones of 59 cave bears were examined.
Genetic analysis
French researchers extracted mitochondrial DNA from a 32,000-year-old sternum discovered in the Chauvet Cave and compared it with the mitochondrial DNA of a brown bear from the Pyrenees . According to the results of this study published in 2008, the cave bears are closely related to the polar bears and the brown bears; the three species therefore descend from a common ancestor. All other bear species living today are descended from a different branch of the bear family tree.
Within the cave bear line, three genetically distinct forms can be identified in the late Pleistocene, which are sometimes viewed as separate species. The forms in western Europe are usually equated with the nominal species Ursus spelaeus , while the cave bears of Eastern Europe are referred to as Ursus ingressus . The Alpine region forms the border area between the two forms. A third form is known from the Caucasus. Genetically, it differs greatly from the other cave bears and is known as Ursus deningeri kudarensis . It was only in the recent past that cave bear remains from North and Central Asia became known. A find from northern Siberia was identified by DNA analysis as a close relative of the Caucasian cave bear. Amazingly, cave bears from the Altai Mountains turned out to be close relatives of the Western European cave bear.
The cave bear hybridized with the brown bear. Sections of the cave bear genome can still be found in the brown bear DNA today. About 0.9 to 2.4% of the brown bear genome comes from the cave bear.
literature
- Ernst Probst: The cave bear. Diplomica Verlag, Hamburg 2015, ISBN 978-3-95934-561-3 .
- Gernot Rabeder, Doris Nagel, Martina Pacher: The cave bear. Jan Thorbecke Verlag, Stuttgart 2000, ISBN 3-7995-9085-4 .
Web links
Individual evidence
- ^ Ernst Probst: Der Höhlenbär Diplomica Verlag, June 15, 2015; P. 101
- ↑ Yuichi I. Naito et al .: Evidence for herbivorous cave bears (Ursus spelaeus) in Goyet Cave, Belgium: implications for palaeodietary reconstruction of fossil bears using amino acid δ15N approaches. Journal of Quaternary Science, August 2016, DOI: 10.1002 / jqs.2883
- ↑ Johann Friedrich Esper: Detailed reports from newly discovered zooliths of unknown quadruped animals. Georg Wolfgang Knorrs Seel. Erben, Nuremberg 1774. (Facsimile edition: Guido Pressler, Wiesbaden 1978; Introduction: Armin Geus)
- ↑ Johann Christian Rosenmüller: Quaedam de ossibus fossilibus animalis cujusdam, historiam ejus et cognitionem accurationem illustrantis (German, even originating from the author translation). Dissertation . Leipzig 1795.
- ↑ Stephan Kempe, Doris Döppes: Cave bear, cave lion and cave hyena skulls from the public collection at the Humboldt Museum in Berlin. In: Acta Carsologica. 38 / 2–3, 2009, pp. 253-264.
- ↑ Stephan Kempe, Wilfried Rosendahl, Doris Döppes: The making of the cave bear - The scientific discovery of Ursus spelaeus. In: Festschrift G. Rabeder Mitt. Komm. Quaternary research. Austrian Akad. Wiss. 14, 2005, pp. 57-73.
- ↑ Stephan Kempe, Wilfried Rosendahl, Doris Döppes: The scientific discovery of "Ursus spelaeus". In: New Research on Cave Bears in Europe, 11th International Cave Bear Symposium, September 29 - October 2, 2005, Naturhistorische Gesellschaft Nürnberg e. V., treatises. Volume 45, 2005, pp. 199-214.
- ↑ Wilfried Rosendahl, Stephan Kempe: Ursus spelaeus ROSENMÜLLER 1794 and not ROSENMÜLLER & HEINROTH - Johann Christian Rosenmüller, his life and the Ursus spelaeus. In: New Research on Cave Bears in Europe, 11th International Cave Bear Symposium, September 29 - October 2, 2005, Naturhistorische Gesellschaft Nürnberg e. V., treatises. Volume 45, 2005, pp. 191-198.
- ^ Susanne C. Münzel, Nicholas J. Conard: Cave Bear Hunting in the Hohle Fels, a Cave Site in the Ach Valley, Swabian Jura. In: Revue de Paléobiologie. 23 (2), 2004, pp. 877-885.
- ^ Photo and report of the findings from the hollow rock
- ^ Martina Pacher, Anthony J. Stuart: Extinction chronology and palaeobiology of the cave bear ( Ursus spelaeus ). In: Boreas. Volume 38 Issue 2, 2009, pp. 189-206. doi : 10.1111 / j.1502-3885.2008.00071.x
- ↑ Nadja Podbregar: Why did the cave bear die out? In: Wissenschaft.de . August 15, 2019, accessed August 18, 2019 .
- ↑ Joscha Gretzinger u. a .: Large-scale mitogenomic analysis of the phylogeography of the Late Pleistocene cave bear. In: Scientific Reports. 9, 2019, doi : 10.1038 / s41598-019-47073-z .
- ↑ Celine Bon et al .: Deciphering the complete mitochondrial genome and phylogeny of the extinct cave bear in the Paleolithic painted cave of Chauvet. In: Proceedings of the National Academy of Sciences of the USA . (PNAS), 2008. doi: 10.1073 / pnas.0806143105
- ↑ M. Knapp, N. Rohland, J. Weinstock, G. Baryshnikov, A. Sher, D. Nagel, G. Rabeder, R. Pinhasi, HA Schmidt, M. Hofreiter: First DNA sequences from Asian cave bear fossils reveal deep divergences and complex phylogeographic patterns. In: Molecular ecology. vol. 18, Mar. 2009, pp. 1225-1238.
- ↑ Axel Barlow at al .: Partial genomic survival of cave bears in living brown bears , Nature Ecology & Evolution (2018), doi: 10.1038 / s41559-018-0654-8