Homeomorphic gastropods from the Silurian of Norway, Estonia and Bohemia

Citation
M. Isakar et al., Homeomorphic gastropods from the Silurian of Norway, Estonia and Bohemia, NORSK GEOL, 79(4), 1999, pp. 281-288
Citations number
36
Categorie Soggetti
Earth Sciences
Journal title
NORSK GEOLOGISK TIDSSKRIFT
ISSN journal
0029196X → ACNP
Volume
79
Issue
4
Year of publication
1999
Pages
281 - 288
Database
ISI
SICI code
0029-196X(1999)79:4<281:HGFTSO>2.0.ZU;2-P
Abstract
Redescription of the gastropod Euomphalus undiferus Schmidt, 1858 from dir Upper Llandovery Rumba Formation of Estonia requires reinvestigation of the hitherto monotypic genus Kiaeromphalus Peel & Yochelson, 1976, originally described from the Rytteraker Formation of the Oslo Region. The Estonian K. undiferus and the Norwegian type species occur in similar depositional fac ies of Early Silurian age within the sedgwickii Graptolite Zone. The redesc ribed type specimen of Horologium kokeni Perner, 1907 from the late Siluria n (Ludlow) of Bohemia shows strong morphological convergence with the two B altic species, but Kiaeromphalus is distinguished by its lower rate of whor l expansion and less oblique aperture, Both genera were adapted to a sessil e life, possibly on a soft substratum.