Cyrthoceratites depressus, from Museum Victoria.

Belongs within: Oncocerida.

The Nothoceratidae are a group of cephalopods known from the Silurian and Devonian. Nothoceratid shells varied from short and curved to coiled, with the mature aperture being variously constricted.

Characters (from Sweet 1964): Depressed (or primitively compressed), exogastric or endogastric brevicones, nautilicones, and torticones with contracted or visored apertures and ventral, generally concavosiphonate siphuncle occupied by actinosiphonate deposits.

|--Oligoceras russanovi (Kuzmin 1965)K93
|--Nothoceras Barrande 1856S64
| `--*N. bohemicum Barrande 1867S64, K93
|--Lorieroceras Foerste 1926S64
| `--*L. lorieri (Barrande 1874)S64, K93 [=Trochoceras lorieriS64]
|--Perimecoceras Foerste 1926S64
| `--*P. contrastans (Barrande 1877) [=Cyrtoceras contrastans]S64
|--Turnoceras Foerste 1926S64
| `--*T. turnus (Barrande 1877)S64 [=Cyrtoceras turnusS64, Cranoceras turnusH84]
`--Conostichoceras Foerste 1926S64
|--*C. palinurus (Barrande 1877) [=Cyrtoceras palinurus]S64
`--C. hardmani (Etheridge 1897) [=Actinoceras hardmani]F71

*Type species of generic name indicated


[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1–167.

[H84] Hyatt, A. 1883–1884. Genera of fossil cephalopods. Boston Soc. Nat. History, Proc. 22: 253–338.

[K93] King, A. H. 1993. Mollusca: Cephalopoda (Nautiloidea). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 169–188. Chapman & Hall: London.

[S64] Sweet, W. C. 1964. Nautiloidea—Oncocerida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt K. Mollusca 3. Cephalopoda—General Features—Endoceratoidea—Actinoceratoidea—Nautiloidea—Bactritoidea pp. K277–K319. The Geological Society of America and the University of Kansas Press.

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