Ethminolia wareni

Helwerda, Renate Ariane, Wesselingh, Frank Pieter & Williams, Suzanne T., 2014, On some Vetigastropoda (Mollusca, Gastropoda) from the Plio-Pleistocene of the Philippines with descriptions of three new species, Zootaxa 3755 (2), pp. 101-135 : 123

publication ID	https://doi.org/ 10.11646/zootaxa.3755.2.1
publication LSID	lsid:zoobank.org:pub:1872ECAB-3C5C-4D76-93A0-A8626F75B96E
DOI	https://doi.org/10.5281/zenodo.5671310
persistent identifier	https://treatment.plazi.org/id/490087B3-FFAB-6D36-FF1F-FF2C59ABFC15
treatment provided by	Plazi
scientific name	Ethminolia wareni
status

Treatment

Ethminolia wareni View in CoL nov. spec.

( Figures 50–52 View FIGURES 45 – 52 )

Type material. Holotype RGM 608.321, paratypes RGM 608.322 and RGM 608.323 (Anda 4).

Type locality. Anda 2, Bolinao, Philippines, Santa Cruz Formation, Pliocene or Early Pleistocene.

Derivatio nominis. Named after Anders Warén (Swedish Museum of Natural History), a prominent deepwater malacologist.

Other material. Anda 1 (74); Anda 2 (66); Anda 3 (28); Anda 4 (42); Anda 5 (3); Anda 6 (11); AndaDeVos (27); AndaClif 1 (1); AndaClif 3 (4); Roxas (3); Tiep 1 (1); Tiep 3 (18); Tiep 4 (2); Tiep 5 (27).

Diagnosis. Shell low conical, H 3.0 mm, W 4.4 mm; DN 0.10–0.12 mm; early teleoconch whorls angular; later whorls with subsutural row of knobs; two peripheral ribs; many weak ribs on base; open umbilicus with furrowed umbilical ridge.

Description. This shell is conical with a low spire (H/W ratio 0.67). Larger specimens are covered with brownish blotches and a nacreous shine. The protoconch is small, smooth and consists of 1.1 whorls. The P/T boundary is marked by an adnate varix. After the boundary, three spiral cords are present. The upper rib becomes more prominent and shouldered, while the lower ribs gradually disappear after two whorls. On the third whorl, a spiral row of knobs is gradually formed directly below the suture. The rib and the shoulder it delimits gradually disappear on the fourth whorl. Growth lines are microscopic. The body whorl has two spiral ribs on the periphery and many weak spiral ribs on the base. The aperture is broken in all specimens, but it appears to be subquadrate, with a straight columellar lip. The umbilicus is deep and staircase-like, because of the straight angle of the columella and the base. The edge of the umbilicus has many narrow furrows.

Differentiation. This species differs from E. nektonica ( Okutani, 1961) by the lack of spiral ribs on the upper side of the later whorls, while E. nektonica ( Okutani, 1961) has rather strong spiral ribs on the apical side of these whorls. The subsutural row of knobs is more pronounced in E. wareni .