Valcouroceratidae

Belongs within: Oncoceratida.

The Valcouroceratidae were mostly breviconic (short-shelled) oncocerid cephalopods from the Middle to Upper Ordovician. In mature individuals, bladelike lamellae called actinosiphonate deposits developed within the siphuncle (Sweet 1964).

Characteristics (from Sweet 1964): Exogastric cyrtocones and brevicones with ventral, actinosiphonate siphuncle; conch changes during ontogeny from compressed to depressed or subtriangular section.

<==Valcouroceratidae
    |--Actinomorpha Flower 1943S64
    |    `--*A. pupa Flower 1943S64
    |--Kindleoceras Foerste 1924S64
    |    `--*K. reversatum Foerste 1924S64
    |--Manitoulinoceras Foerste 1924S64
    |    `--*M. lysander (Billings 1865) [=Cyrtoceras lysander]S64
    |--Minganoceras Foerste 1938S64
    |    `--*M. subturbinatum (Billings 1857) [=Cyrtoceras subturbinatum]S64
    |--Staufferoceras Foerste 1932S64
    |    `--*S. featherstonhaughi (Clarke 1897) [=Cyrtoceras featherstonhaughi]S64
    |--Augustoceras Flower 1946S64
    |    |--*A. shideleri Flower 1946S64
    |    `--A. molense Stait 1982K93
    |--Valcouroceras Flower 1943S64
    |    |--*V. bovinum Flower 1943S64
    |    `--V. elongatum Flower 1952P68
    |--Hemibeloitoceras ellipsoidale Balashov 1962K93
    |    |--H. e. ellipsoidaleK93
    |    `--H. e. nujense Balashov 1962K93
    `--Fayettoceras Foerste 1932S64
         |--*F. thompsoni (Miller 1894) [=Cyrtoceras thompsoni]S64
         |--F. beloitense Foerste 1932-1933P68
         `--F. canyonense Foerste 1935P68

*Type species of generic name indicated

References

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

[P68] Purnell, L. R. 1968. Catalog of the type specimens of invertebrate fossils. Part I: Paleozoic Cephalopoda. United States National Museum Bulletin 262: 1–198.

[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.