| Autor: |
Baker, Peter G., Wilson, Mark A. |
| Předmět: |
|
| Zdroj: |
Palaeontology; Sep99, Vol. 42 Issue 5, p887, 9p, 4 Black and White Photographs |
| Abstrakt: |
Restudy of a hardground fauna from the Middle Jurassic of south-western Utah revealed the presence of thecideoid brachiopods. The absence of separated dorsal valves and the effects of abrasion and diagenesis hampered the description of the specimens. However, serial sectioning of complete shells revealed a thecidellinid which in its morphology and shell microstructure resembledRioultinaPajaud from the Middle Jurassic of Europe. Important morphological differences clearly separate the new specimens fromRioultinaand they are assigned toStentorina sagittatagen. et sp. nov. However, the close approximation of certain shell microstructural features does suggest a phylogenetic link between the two genera.S. sagittatais also compared with the only other known American Jurassic species,Ancorellina ageriManceñido and Damborenea from the Lower Jurassic of Argentina. Differences in morphological characters currently of family rank preclude the possibility ofStentorinabeing descended fromAncorellinastock. It is considered, therefore, that dispersal from Tethyan thecideoid populations to America occurred several times. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
Plný text