Ageria Abbass 1973
Ageria sp. Figs 29 F–G Material. A moderately well preserved external and internal mould (MGUH 33229), which may be mislaid, and a poorly preserved external mould MGUH 33230. Occurrence. Lithified top of the Højerup Member of the Maastrichtian Tor Formation at Rødvig and Holtug Quarry, Stevns Klint....
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| Format: | Text |
| Language: | unknown |
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Zenodo
2019
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| Online Access: | https://dx.doi.org/10.5281/zenodo.5582885 https://zenodo.org/record/5582885 |
| Summary: | Ageria sp. Figs 29 F–G Material. A moderately well preserved external and internal mould (MGUH 33229), which may be mislaid, and a poorly preserved external mould MGUH 33230. Occurrence. Lithified top of the Højerup Member of the Maastrichtian Tor Formation at Rødvig and Holtug Quarry, Stevns Klint. Description. Protoconch not known. Teleoconch whorls flattened, relatively high, the height corresponding to about 60 % of width, separated by shallow suture. Keel on last whorl very sharp, delineated adapically by wide furrow. Base strongly flattened. Aperture subrectangular, slightly flaring with two low spiral folds on outer lip. Teleoconch sculpture changing with growth; initial whorls carrying about 14 coarse, slightly opisthocline transverse ribs fading out towards sutures; ribs terminating abapically towards weak spiral rib delineating beaded keel. Transverse ribs fading out on later whorls, being replaced by three beaded spiral ribs; adapical keel ramp carrying three weak spiral threads. Growth lines opisthocyrt and slightly opisthocline. Measurements. Teleoconch on disappeared specimen at least 11.2 mm high and 3.7 mm wide, consisting of nine whorls. Remarks. Ageria sp. resembles Ageria gankinensis Kaim et al ., 2004 from the Late Maastrichtian of Siberia, but differs by the denser sculpture with three instead of two primary beaded spiral ribs adapical to the keel. It seems to differ from Ageria skeldervigensis n. sp. described above from the same deposits by the relatively high whorls and extremely sharp keel, but a very limited material prevents any definite conclusions as the differences could reflect ecophenotypic variation. : Published as part of Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, pp. 1-196 in Zootaxa 4654 (1) on page 126, DOI: 10.11646/zootaxa.4654.1.1, http://zenodo.org/record/3365803 : {"references": ["Kaim, A., Beisel, A. L. & Kurushin, N. I. (2004) Mesozoic gastropods from Siberia and Timan (Russia). Part 1: Vetigastropoda and Caenogastropoda (exclusive of Neogastropoda). Polish Polar Research, 25, 241 - 266."]} |
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