Depressipoma laddi, Mclean, 2012

Mclean, James Hamilton, 2012, New species and genera of colloniids from Indo-Pacific coral reefs, with the definition of a new subfamily Liotipomatinae n. subfam. (Turbinoidea, Colloniidae), Zoosystema 34 (2), pp. 343-376 : 370

publication ID

https://doi.org/ 10.5252/z2012n2a10

persistent identifier

https://treatment.plazi.org/id/6C26A814-FF9F-1474-D9DA-7E8D6902F717

treatment provided by

Felipe

scientific name

Depressipoma laddi
status

sp. nov.

Depressipoma laddi View in CoL n. sp.

( Fig. 14 View FIG D-F)

Liotina (Austroliotia) cf. L. botanica (Hedley) ” – Ladd 1966: 46, pl. 7, figs 9-11.

TYPE MATERIAL. — Holotype: U.S. Geological Survey , 1946-1952, Eniwetok Atoll, Marshall Islands, Elugelab Islet, sub-Recent from shallow drill hole, 11°40’N, 162°13’E, specimen slightly beach-worn at time of deposition, H 1.4, D 3.3 mm ( USNM 648301 About USNM ). GoogleMaps

TYPE LOCALITY. — Eniwetok Atoll, Marshall Islands.

DISTRIBUTION. — Known only from holotype.

ETYMOLOGY. — Named after the late Dr. Harry S. Ladd, Department of Paleobiology, USNM, who first illustrated this species.

DESCRIPTION

Shell ( Fig. 14 View FIG D-F)

Of 2.7 whorls; profile very low for genus; whorls with weak peripheral angulation high on whorl; whorls rounded and inflated above and below angulation. Axial sculpture of 27weak,narrow ribs, weakly spinose and projecting in early whorls, but losing all spination in final whorl.Spiral sculpture of narrow ribs, forming square cancellations and pits;upper half of whorl with four weak cords, lower with three cords; emergent cord not strongly defined.Umbilical slope broad, with raised, narrow extensions of axial sculpture; umbilicus fully occluded by callus,partially obstructed by massive extension of inner lip, forming tongue that slightly projects forward but not extending near coiling axis. Final lip massive,extending for∕₄of final quarter whorl, with successively decreasing layers of deposition, with indentations conforming to spiral sculpture.Aperture slightly oblique, plane of aperture aligned with coiling axis. H 1.4, D 3.3 mm (holotype).

Operculum

Unknown. REMARKS

This species is unlike the other species of Depressipoma n. gen. and all species of Liotipoma in having axial ribs that are not strongly projecting at the periphery, in either apical or basal view, except in the early stages. The sculpture of the base is more clathrate than that of other species.

This species is unlikely to be sexually dimorphic because its low profile would not allow room for a brooding cavity in the umbilicus.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Trochida

Family

Colloniidae

Genus

Depressipoma

Loc

Depressipoma laddi

Mclean, James Hamilton 2012
2012
Loc

Liotina (Austroliotia)

LADD H. S. 1966: 46
1966
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