Austrotoma obsoleta
| Austrotoma obsoleta | |
|---|---|
 | |
| Shell of Austrotoma obsoleta (holotype) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Order: | Neogastropoda |
| Family: | Pseudomelatomidae |
| Genus: | Austrotoma |
| Species: | †A. obsoleta |
| Binomial name | |
| †Austrotoma obsoleta H. J. Finlay, 1926 | |
Austrotoma obsoleta is an extinct species of sea snail, a marine gastropod mollusc, in the family Pseudomelatomidae.[1]
Description
The length of the shell attains 26.5 mm, its diameter 12.5 mm.
(Original description) The shell retains the general characteristics of † Austrotoma minor (Finlay, 1924), though it is shorter and its axial ribs are only faintly visible on the first few whorls. Along the spire-whorls, seven spiral cords run distinctly: the upper three merge into a pronounced subsutural ridge, followed by a narrow, deeply concave, and smooth sinus space, beneath which lie four additional cords.
On the body whorl, between this sinus space, there are twelve to fourteen spirals, separated by broad, deep interstices that are sometimes threaded with finer interstitial lines. The shell itself appears squat, with a spire that is shorter than the aperture. The columella is more deeply excavated above than in the preceding species, and the siphonal canal is correspondingly shorter, while all other features remain essentially the same. [2]
Distribution
This extinct marine species occurs in the Upper Miocene strata near North Canterbury, New Zealand.[3]
References
- ↑ Austrotoma obsoleta H. J. Finlay, 1926. 5 May 2026. Retrieved through: World Register of Marine Species.
- ↑ Finlay, H.J. (1926). "Finlay". Transactions of the New Zealand Institute. 56: 253. Retrieved 5 May 2026.
This article incorporates text from this source, which is under a CC BY 4.0 license. - ↑ Powell, A.W.B. (1942). "The New Zealand recent and fossil Mollusca of the family Turridae with general notes on turrid nomenclature and systematics". Bulletin of the Auckland Institute and Museum. 2: 76. Retrieved 29 April 2026.
This article incorporates text from this source, which is in the public domain.
- Beu, A.G. & Maxwell, P.A. (1990) Cenozoic Mollusca of New Zealand. New Zealand Geological Survey Paleontological Bulletin, 58, 1–518.
- Maxwell, P. A. (2009). Cenozoic Mollusca. Pp 232-254 in Gordon, D. P. (ed.) New Zealand inventory of biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Canterbury University Press, Christchurch