Observations on astiericeras astierianum (d'Orbigny, 1842) (Cretaceous Ammonoidea)
By: Kennedy, W.J
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Material type: 
ArticleDescription: 507-513pp ; Illustration.Subject(s): Cretaceous | Invertebrata - France | Paleontology | Mollusca | Fossil
In:
Geological magazine : Vol. 123 Iss. 1-6 Year. 1986Summary: Astiericeras astierianum (d'orbigny, 1842) is redescribed, the type material illustrated for the first time and the range of intraspecific variation and striking sexualdimorphism documented. Previous suggestions that the early ontogeny of Astiericeras supports derivation from Douvilleiceras de Grossouvre, 1894 of the Douvilleiceratinae are in error: the genus and species are distinctive at the earliest diameters seen and ornament gives no clue to affinities. The sutural formula is that characteristic of some Douvilleicerataceae, however, to which superfamily the species is assigned, as the only member of the family Astiericeratidae Breistroffer, 1953. It is thus a scaphitoid heteromorph, derived from normally coiled immediate ancestors that are themselves recoiled derivatives of an original heteromorphic stock.
| Item type | Current location | Collection | Call number | Status | Date due | Barcode |
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Article
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Library and Information Centre Periodical Section | Bound Journal Collection | Not for loan | 002533_115 | ||
Serials/Scientific Journal
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Library and Information Centre Periodical Section | Bound Journal Collection | 550 GEO (Browse shelf) | Available | 002533 |
Astiericeras astierianum (d'orbigny, 1842) is redescribed, the type material illustrated for the first time and the range of intraspecific variation and striking sexualdimorphism documented. Previous suggestions that the early ontogeny of Astiericeras supports derivation from Douvilleiceras de Grossouvre, 1894 of the Douvilleiceratinae are in error: the genus and species are distinctive at the earliest diameters seen and ornament gives no clue to affinities. The sutural formula is that characteristic of some Douvilleicerataceae, however, to which superfamily the species is assigned, as the only member of the family Astiericeratidae Breistroffer, 1953. It is thus a scaphitoid heteromorph, derived from normally coiled immediate ancestors that are themselves recoiled derivatives of an original heteromorphic stock.
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