Hesperiella planorbis, Yoo, 1994
publication ID |
https://doi.org/ 10.3853/j.0067-1975.46.1994.18 |
DOI |
https://doi.org/10.5281/zenodo.4657437 |
persistent identifier |
https://treatment.plazi.org/id/03EB87C3-861D-6B3B-FE15-85E2F7D5FA2E |
treatment provided by |
Felipe |
scientific name |
Hesperiella planorbis |
status |
sp. nov. |
Hesperiella planorbis View in CoL n.sp.
PI. 7 figs 9-13
Description. Shell very small, low spired, sinistral, broadly phaneromphalous. Protoconch coiling inward and hidden by later whorls, but seen in umbilicus, smooth, one and one eighth whorls, apex bulbous. Teleoconch with first I? whorls planispiral, becoming ultradextral, growth lines in early whorls but gradually becoming stronger; collabral lirae above selenizone, opisthocline below selenizone; fine collabral thread extended to umbilicus. Selenizone present from early teleoconch whorl, narrow on periphery. Aperture round; inner and parietal lips thin, outer lip thickened; slit is seen in juvenile shells.
Types. Holotype ( F78402 View Materials ) and 3 figured paratypes ( F78403 View Materials ). There are 15 unfigured additional specimens ( F78404 View Materials ) from the type locality.
Type locality. 150 m west of 'Marohn' homestead, on the Scone-Gundy roadside, 4 km south-west of Gundy, NSW (Locality 28).
Stratigraphic position. In bioclastic limestone, in upper part of the Dangarfield Formation.
Additional material. 1 specimen from Glenbawn (Locality 31) and 1 from Swains Gully (Locality 25).
Geographic distribution. Swains Gully to Glenbawn.
Geological age. Middle to late Tournaisian.
Etymology. Referring to the planispirally coiled early stage of development of the shell.
Remarks. This species differs from other species of this genus in having a low-spired shell, a very wide umbilicus, and a flattened selenizone. The protoconch and nepionic whorls are planispiral and the early ontogenetic pattern of development is seen through the umbilicus. Two figured paratypes are juveniles.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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