''Mauidrillia consutilis'' is an extinct species of

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk in the family

Horaiclavidae Horaiclavidae is a family of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. In 2011 this family was split off from the family Pseudomelatomidae (formerly the subfamily Crassispirinae McLean, 1971) by Bouchet P., Ka ...

.G.F. Harris (1897), Catalogue of Tertiary Mollusca in the Department of Geology, British Museum (Natural History) part I p. 41
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Description

Dimensions: length 12 mm; breadth 5 mm; length of the aperture 5 mm. (Original description) Though this shell is destitute of any striking ornamentation, it is easily distinguished from the species already described. It is very neatly, obliquely cancellate, the transverse and longitudinal lines being very neat, distinct, equal, and sufficiently distant to leave very definite rhomboidal spaces. The whorls are keeled in the middle, about which there is a rather broad, fiat, shallow, groove which corresponds to the sinus. It has a fine line in the centre, and is closely transversely marked with elegant curved ribs. The aperture is wide, the outer lip is much produced in the middle, and the sinus is very conspicuous, wide and deep. The siphonal canal is twisted. The neat distant cancellation, and the fine lines on the groove give the surface an appearance of open thread work, hence the name.Proceedings of the Linnean Society of New South Wales vol. 4 (1880)
/ref> The

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

is composed of 1½ smooth, shining

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane flo ...

s, the anterior portion of which is obtusely keeled medially. This keel develops into a strong feature in the brephic and neanic stages, but on approaching the adult is not so clearly marked. The shell is small and fusiform. The whorls are obliquely cancellate. The transverse and longitudinal lines are regularly spaced. The aperture is broad. The outer lip is much produced towards the middle. The sinus is broad, deep, and some distance from the suture. The columella is distinctly twisted. The anterior is canal short.

Distribution

Fossils of this extinct species were found in

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...

strata in Victoria, Australia.

References

{{DEFAULTSORT:Mauidrillia Consutilis consutilis Gastropods described in 1880 Gastropods of Australia