Dentition and first postcranial description of Metaschizotherium fraasi KOENIGSWALD, 1932 (Perissodactyla: Chalicotheriidae) and its occurrence on a karstic plateau - new insights into schizotheriine morphology, relationships, and ecology

作者：Fahlke Julia M^*; Coombs Margery C

来源：Palaeontographica Abteilung A-Palaozoologie-Stratigraphie, 2009, 290(1-3): 65-+.

DOI：10.1127/pala/290/2009/65

• Metaschizotherium
• Schizotheriinae
• chalicothere
• Petersbuch
• MN 6

Karst fissure fillings of Petersbuch (MN 6), Franconian Alb, Southern Germany, yielded a large number of new finds of the schizotheriine chalicothere Metaschizotherium fraasi, which until then had only been known by its cheek teeth, co-ossified phalanges, and astragalus and calcaneum. Thus, for the first time the lower jaw, the almost complete manus and pes, the tibia, and parts of other long bones are described. New information on the dentition is gained and the presence of well-developed lower incisors is noted. A comprehensive morphological comparison to other schizotheriine chalicotheres is carried out. The species status of M fraasi within the genus Metaschizotherium is confirmed. M fraasi is found to be closely related to but not directly decended from the slightly older M bavaricum (southern German MN 5-6). The morphological resemblance of Metaschizotherium to North American Moropus is striking and reveals a closer relationship than previously assumed. The referral of Metaschizotherium to the Eurasian and African genus Ancylotherium is rejected. Several formerly insecurely referred schizotheriine remains from Europe are now more securely assigned to either Metaschizotherium or Ancylotherium. The first immigration of Ancylotherium into Europe is estimated to have happened around MN 7-8. It is not yet clear whether M. fraasi (recorded from the karstic plateau of the Franconian and Swabian Albs) and M bavaricum (known from more humid environments of the Upper Freshwater Molasse) overlapped ecologically or temporally during MN 6. A diet composed of browse and fruit (possibly Celtis) or bark is assumed for M fraasi, and probably the clawed fore feet rather than anterior teeth were used to obtain these food items.

• 出版日期2009-11