Hokkaidoconcha Kaim, Jenkins & Waren 2008 ...
? Hokkaidoconcha sp. (Fig. 6E–I) Description. Abyssochrysoid shells ornamented with strong orthocline axial ribs which do not reach the suture adapically and with numerous spiral riblets which cross over the axial ribs. Growth lines prosocline. Whorl flanks are weakly inflated and the suture moderat...
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Zenodo
2017
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| Online Access: | https://dx.doi.org/10.5281/zenodo.6009570 https://zenodo.org/doi/10.5281/zenodo.6009570 |
| Summary: | ? Hokkaidoconcha sp. (Fig. 6E–I) Description. Abyssochrysoid shells ornamented with strong orthocline axial ribs which do not reach the suture adapically and with numerous spiral riblets which cross over the axial ribs. Growth lines prosocline. Whorl flanks are weakly inflated and the suture moderately incised. Protoconch and aperture not preserved. Material and occurrence: Three specimens preserved as external moulds from seep #3 (all illustrated: PMO 224.759–761); Sassenfjorden, Svalbard; late Tithonian, Late Jurassic. Remarks. ? Hokkaidoconcha sp. is represented only by shell fragments and several features (e.g. protoconch, aperture) could not be observed in the available specimens. This is why we decided to leave this species in open nomenclature. Similar shells have been described by Sohl (1960) from the Late Cretaceous of the USA as species of Melanatria: Melanatria ? cretacea Wade, 1926 and Melanatria ? sp. The genus Melanatria Bowdich, 1822 is considered to be an objective synonym of Pirena Lamarck, ... : Published as part of Nakrem, Hans Arne, 2017, Gastropods from the Late Jurassic - Early Cretaceous seep deposits in Spitsbergen, Svalbard, pp. 351-374 in Zootaxa 4329 (4) on pages 358-359, DOI: 10.11646/zootaxa.4329.4.3, http://zenodo.org/record/1003014 ... |
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