Microdrillia
Microdrillia is a genus of very small sea snails, marine gastropod mollusks in the family Borsoniidae.
Description
The species in this genus are characterized by a well-developed, multispiral, closely coiled protoconch. One to three of its basal whorls are costulate. The body whorl is wholly devoid of costae but spirally carinate. The retral sinus is relatively large, circularly rounded and close to the suture. The aperture is oblique. The columella is callous, with or without plications. The siphonal canal is short or subobsolete.The following species of this genus are also found as fossils in the age range of 48.6 Ma to 0.781 Ma: Microdrillia comatotropis, Microdrillia cossmanni, Microdrillia crispata, Microdrillia harrisi, Microdrillia ouchitae, Microdrillia propetrina, Microdrillia tersa, ''Microdrillia trina''
Distribution
This marine genus occurs in the Gulf of Oman, off South Africa and off Australia.Species
- † Microdrillia aturensis Lozouet, 2017 Microdrillia circumvertens Microdrillia commentica Microdrillia dinos Kilburn, 1986Microdrillia fastosa
- † Microdrillia meyeri Microdrillia niponica Microdrillia optima
- † Microdrillia pakaurangia Powell, 1942Microdrillia patricia Microdrillia pertinax Microdrillia rhomboidales Stahlschmidt, Poppe & Tagaro, 2018Microdrillia sagamiensis Kuroda & Oyama, 1971Microdrillia sansibarica
- † Microdrillia serratula Microdrillia stephensensis Laseron, 1954
- † Microdrillia teretiaeformis A.W. Janssen, 1972 Microdrillia trina Mansfield, 1925Microdrillia triporcata