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2 Geological Quarterly

2 2020

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The history of bears (Ursidae, Carnivora, Mammalia) from Silesia (southern Poland) and the neighbouring areas

Marciszak Adrian Przemysław, Lipecki Grzegorz

Geological Quarterly

2020

Vol. 64, No. 4

876--897

Revision of the Silesian bear fauna, based on material from 152 sites, mainly cave and karstic localities, and also archaeological and open-air sites, shows the presence of 13 forms and species. These records encompass the last 16.5 Ma and may be divided into five main morphophyletic groups. The oldest bears, represented by the genera Ballusia and Ursavus, are dated to 16.5-11 Ma, and belonged to the stem forms of the subfamily Ursinae. After a break of 6 My, the earliest members of the genus Ursus appeared, and all known Pliocene bears in Silesia belong to the genus Ursus were identified as Ursus minimus. They represent one or two migration events. Additionally, between 3.6 and 3.2 Ma, a single occurence of Agriotherium insigne was recorded from the Węże 1 site. A few Early Pleistocene bear records are represented by U. etruscus, which was a probable ancestor of both arctoid and spelaeoid bear lineages. The oldest representative of Ursus ex gr. arctos known so far and assigned to U. a. suessenbornensis is known from one latest Early Pleistocene (1.2-0.9 Ma) locality, while other Polish records of this form require confirmation. The first occurrence of U. deningeri, the oldest taxon within the U. ex gr. deningeri-spelaeus lineage, was recorded from ~700 ka deposits in Silesia. During the pronounced cold period of MIS 12, the Scandinavian ice sheet covered almost the entire modern territory of Poland, with the exception of the Sudetes and the Carpathians. The accompanying drastic faunal turnover led to the formation of the pan-Eurasian Mammoth Fauna at ~460 ka. At that time a characteristic member of this fauna, the steppe brown bear Ursus arctos priscus, a specific ecomorph adapted to live in open grasslands, appeared in this region. It survived until the beginning of MIS 1, when modern Ursus arctos arctos appeared in Silesia and survived to the present day. U. deningeri was the most common bear during the Middle Pleistocene, while the first records of U. spelaeus spelaeus appeared since MIS 7. The latter form was replaced by U. ingressus during the Late Pleistocene (~110-100 ka). Spelaeoid bears totally dominated the cave assemblage, and finally vanished between 27 and 24 ka.

Fossil bear material from the oldest deposits in the Jasna Strzegowska cave (Silesia, southern Poland)

Marciszak Adrian Przemysław, Lipecki Grzegorz

Geological Quarterly

2020

Vol. 64, No. 4

861--875

Fossil bear material from the lowermost deposits of the Jasna Strzegowska cave is described and its taxonomic status assessed. Comparison with bear remains from other Early and early Middle Pleistocene localities of Eurasia shows the presence of two bear species: Ursus etruscus and U. deningeri, based on morphological and size characters of the teeth and postcranial bones. The teeth of U. deningeri from the Jasna Strzegowska cave are larger, wider and have much more complicated occlusal surfaces when compared with the teeth of U. etruscus. Both bear species are characterized by relatively short and robust metapodials, although those of U. etruscus are on average less massive. Some differences in muscle attachments and articular surfaces have also been found. Metapodials of primitive arctoid bears, that co-occurred with U. etruscus and U. deningeri, are much longer and slimmer. U. etruscus and U. deningeri probably did not live in the Jasna Strzegowska cave at the same time. Based on its time range in Eurasia and morphological characteristics, the age of U. etruscus is estimated as Early Pleistocene, between 1.8-1.3 Ma. This is its first description from Poland, and the remains described are in size and morphology indistinguishable from material from other European localities. For U. deningeri, an early Middle Pleistocene age is suggested.