- Tytuł:
- Gladius shape variation in coleoid cephalopod Trachyteuthis from the Upper Jurassic Nusplingen and Solnhofen Plattenkalks
- Autorzy:
-
Fuchs, D
Engeser, T.
Keupp, H. - Powiązania:
- https://bibliotekanauki.pl/articles/21066.pdf
- Data publikacji:
- 2007
- Wydawca:
- Polska Akademia Nauk. Instytut Paleobiologii PAN
- Tematy:
-
gladius
Cephalopoda
systematics
variation
Vampyropoda
coleoid cephalopod
morphology
Trachyteuthis
paleontology
phylogenetic implication
Coleoidea - Opis:
- Although the fossil record of coleoid cephalopods is generally poor, the Upper Jurassic Nusplingen and Solnhofen Plattenkalks have provided numerous well−preserved coleoids. Trachyteuthis hastiformis, a comparatively large vampyropod coleoid, was previously known to represent the sole species of its genus in Nusplingen and Solnhofen. However, morphological comparisons based on 50 specimens from different museum collections revealed two additional species: T. nusplingensis sp. nov. and T. teudopsiformis sp. nov. Both species lack the distinct spindle−shaped elevation on the gladius median field typical for T. hastiformis. T. nusplingensis sp. nov. is clearly characterised by a smooth median field and a more or less regular granulation on the dorsal gladius surface, whereas T. teudopsiformis sp. nov. can be easily distinguished by the presence of a Teudopsis−like median keel and an extremely narrow granulation. Morphometric analyses have shown that length−width indices are ambiguous characters to differentiate between the three species. Phylogenetically, the keeled and anteriorly pointed T. teudopsiformis sp. nov. can be linked with the Early Jurassic genus Teudopsis and the Late Cretaceous genus Glyphiteuthis.
- Źródło:
-
Acta Palaeontologica Polonica; 2007, 52, 3
0567-7920 - Pojawia się w:
- Acta Palaeontologica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł