| Autor: |
Malcolm C. McKenna, John R. Wible, Guillermo W. Rougier, Michael J. Novacek |
| Rok vydání: |
2001 |
| Předmět: |
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| Zdroj: |
American Museum Novitates. 3322:1-44 |
| ISSN: |
0003-0082 |
| DOI: |
10.1206/0003-0082(2001)322<0001:eeerap>2.0.co;2 |
| Popis: |
A right petrosal from the ?Aptian or Albian Khoobur locality is referred on the basis of size and morphology to Prokennalestes trofimovi, the earliest eutherian previously known only from dentigerous elements. The petrosal shows a mosaic of primitive and derived features, bearing on the purported therian and eutherian morphotypes. Among the primitive features shared with the Early Cretaceous prototribosphenidan Vincelestes and other more basal taxa that are modified in later eutherians and metatherians are the pattern of basicranial arterial and venous circulation, including a prootic canal and an intrapetrosal inferior petrosal sinus; a vertical paroccipital process; and a fenestra semilunaris, an incomplete wall between the cavum epiptericum and cavum supracochleare. Among the derived features shared with therians is a cochlea coiled through a minimum of 360°, with Prokennalestes extending the range of the oldest occurrence of such a coiled cochlea by at least 10 million years. Shared with Late... |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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