LIOTIPOMATINAE, 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 : 346-347

Subfamily LIOTIPOMATINAE n. subfam.

TYPE GENUS. — Liotipoma McLean & Kiel, 2007 .

DIAGNOSIS. — Aperture round with complete peristome; operculum multispiral, low conical on inner surface, outer surface of operculum with central pit, rugose with central pit, or rugose throughout. Shell with fine axial lamellae and larger cancellate sculpture; expansion of whorl increasing at final stage, final lip broadly expanded, and thickened with layered lamellae that decrease in diameter at terminal stage; umbilicus broadly open, but blocked by extension of inner lip; aperture nearly radial. DISTRIBUTION. — Indo-Pacific coral reefs. Each of the four genera have limited, non-overlapping distributions: Liotipoma is known from island groups south of the equator, including Papua New Guinea, New Caledonia, Lifou, Fiji, Wallis Island, and Espiritu Santo, Vanuatu. Rhombipoma n. gen. is known from further east at Rowley Shoals, northwestern Australia.Two of the new genera are known from north of the equator: Paraliotipoma n. gen. is known from Seahorse Shoal, South China Sea, and Depressipoma n. gen. is known from the Marshall Islands. FOSSIL RECORD. — Unknown.

LIVING GENERA. — Four living genera are recognised: Liotipoma (moderately high profile with peripheral angulation and apertural tongue); Paraliotipoma n. gen. (moderately high profile lacking apertural tongue); Depressipoma n. gen. (discoidal with angulate periphery); Rhombipoma n. gen. (discoidal, with rounded periphery).

REMARKS

The new subfamily is characterised by sculpture of fine axial lamellae, which is unknown in the Cretaceous Petropomatinae . Preserved specimens are yet unknown; all specimens have been recovered from sediment samples, including some in fresh condition with wedged-in opercula.