Bactroceratidae King & Evans 2019
Family Bactroceratidae King & Evans, 2019 Emended diagnosis Slender orthoconic to weakly cyrtoconic shells with usually faint ornamentation consisting of transverse growth lines or low striae; siphuncle marginal, narrow; dorsomyarian muscle scars; septal necks orthochoanitic to hemichoanitic, co...
| Main Authors: | , |
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| Format: | Other/Unknown Material |
| Language: | unknown |
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2021
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| Online Access: | https://zenodo.org/record/5793504 https://doi.org/10.5281/zenodo.5793504 |
| Summary: | Family Bactroceratidae King & Evans, 2019 Emended diagnosis Slender orthoconic to weakly cyrtoconic shells with usually faint ornamentation consisting of transverse growth lines or low striae; siphuncle marginal, narrow; dorsomyarian muscle scars; septal necks orthochoanitic to hemichoanitic, connecting rings thin and homogeneous, slightly expanded into chambers; embryonic shell moderately large, subspherical and with constriction; cicatrix absent (slightly modified from King & Evans 2019). Remarks The diagnosis of the Bactroceratidae King & Evans, 2019 is emended with respect to the statement of a presence or absence of endosiphuncular and cameral deposits, which follows a discussion of the type genus of this family (see below). A statement about the presence or absence of deposits is removed from the diagnosis herein. Published as part of Kröger, Björn & Pohle, Alexander, 2021, Early-Middle Ordovician cephalopods from Ny Friesland, Spitsbergen - a pelagic fauna with Laurentian affinities, pp. 1-102 in European Journal of Taxonomy 783 (1) on pages 33-34, DOI:10.5852/ejt.2021.783.1601, http://zenodo.org/record/5793422 |
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