Acleistoceratidae

Belongs within: Oncoceratida.

The Acleistoceratidae were a Middle Silurian to Middle Devonian family of oncocerid cephalopods characterised by a broad siphuncle. Many species had a constricted triangular aperture.

Characters (from Sweet 1964): Depressed (rarely compressed, at least in early stages) exogastric brevicones and cyrtocones; siphuncle broadly expanded, actinosiphonate in some Devonian species.

<==Acleistoceratidae
    |--EocyrtocerasK93
    |--Austinoceras Foerste 1934S64
    |    `--*A. turgidulum Foerste 1934S64
    |--Clionyssiceras Foerste 1930S64
    |    `--*C. petilum Foerste 1930S64
    |--Crateroceras Foerste & Savage 1927S64
    |    `--*C. raymondi Foerste & Savage 1927S64
    |--Galtoceras Foerste 1934S64
    |    `--*G. arcticameratum (Hall 1852) [=Cyrtoceras arcticameratum]S64
    |--Hercocyrtoceras Foerste 1927S64
    |    `--*H. amator (Billings 1866) [=Oncoceras amator]S64
    |--Paracleistoceras Foerste 1926S64
    |    `--*P. devonicans (Barrande 1865) [=Phragmoceras devonicans]S64
    |--Perioidanoceras Foerste 1930S64
    |    `--*P. rotundatum Foerste 1930S64
    |--Poteriocerina Foerste 1926S64
    |    `--*P. lumbosum (Barrande 1877) [=Cyrtoceras lumbosum]S64
    |--Rhomboceras Foerste 1934S64
    |    `--*R. welchi Foerste 1934S64
    |--Slocomoceras Foerste 1930S64
    |    `--*S. retrorsum Foerste 1930S64
    |--Streptoceras Billings 1866S64
    |    `--*S. janus Billings 1866S64
    |--Gonatocyrtoceras Foerste 1926S64
    |    |--*G. heteroclytum (Barrande 1866) [=Cyrtoceras heteroclytum]S64
    |    |--G. gnerichiKE19
    |    |--G. hozapfeliKE19
    |    |--G. longimissimaKE19
    |    `--G. postscripti (Barrande 1866)K93
    |--Anomeioceras Foerste 1930S64
    |    |--*A. compressum Foerste 1930S64
    |    `--A. brevicameratum Foerste 1930P68
    |--Chadwickoceras Foerste 1930S64
    |    |--*C. fusiforme Foerste 1930S64
    |    `--C. erectum Foerste 1930P68
    |--Grimsbyoceras Foerste 1934S64
    |    |--*G. clitus (Billings 1866) [=Cyrtoceras clitus]S64
    |    `--G. hillsboroense Foerste 1934P68
    |--Tumidoceras Flower 1949S64
    |    |--*T. lentum Flower 1949S64
    |    `--T. magnum Flower 1949P68
    |--Acleistoceras Hyatt 1884S64
    |    |--*A. olla (Saemann 1854) [=Apioceras olla]S64
    |    |--A. eximium (Hall 1888)K93
    |    `--A. mitra (Hall 1888)K93
    |--Byronoceras Foerste & Savage 1927S64
    |    |--*B. longidomum Foerste & Savage 1927S64
    |    |--B. commune Foerste 1930P68
    |    `--B. transversale Foerste 1930P68
    |--Ectocyrtoceras Foerste 1930S64
    |    |--*E. marginatum Foerste 1930S64
    |    |--E. gibberosum Foerste 1934P68
    |    `--E. wilmingtonense Foerste 1934P68
    |--Worthenoceras Foerste 1930S64
    |    |--*W. elongatum Foerste 1930S64
    |    |--W. byronense Foerste 1930P68
    |    |--W. curtum Foerste 1930P68
    |    |--W. exiguum Foerste 1930P68
    |    `--W. subfusiforme Foerste 1934P68
    `--Amphicyrtoceras Foerste 1924S64
         |--*A. orcas (Hall 1862) [=Cyrtoceras orcas]S64
         |--A. bownockeri Foerste 1934P68
         |--A. depressum Foerste 1930P68
         |--A. inflatum Foerste 1930P68
         |--A. lateraleS64
         `--A. tantulum Foerste 1924P68

*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.

[KE19] King, A. H., & D. H. Evans. 2019. High-level classification of the nautiloid cephalopods: a proposal for the revision of the Treatise Part K. Swiss Journal of Palaeontology 138: 65–85.

[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.