Longitudinal and transverse sections of the Lower Devonian Jovellania buchi, from Sweet (1964).

Belongs within: Nautilosiphonata.
Contains: Rutoceratidae, Trimeroceratidae, Rizoceratidae, Valcouroceratidae, Jovellaniidae, Nothoceratidae, Polyelasmoceratidae, Oonoceratidae, Diestoceratidae, Hemiphragmoceratidae, Oncoceratidae, Acleistoceratidae, Poterioceratidae.

The Oncoceratida were a highly varied group of cephalopods, mostly breviconic but also including other forms including gyroconic and torticonic species. As recognised by Sweet (1964), the oncocerids lived from the Middle Ordovician to the Lower Carboniferous; however, phylogenetically speaking this group probably also contains the Nautilida which survive to the present day.

Characteristics (from Sweet 1964): Primitively compressed exogastric cyrtocones and brevicones, later also straight, torticonic, gyroconic and nautiliconic forms, many with depressed sections and/or endogastric curvature. Siphuncle on ventral side of centre; septal necks tubular or suborthochoanitic in early stages and primitive forms, cyrtochoanitic in adults and derived forms. Siphuncular segments generally slender, may be large and inflated. Connecting rings usually thin, may be thickened in adult or gerontic individuals and variously produced to form actinosiphonate deposits.

<==Oncoceratida (see below for synonymy)
    |  `--JovellaniidaeS64
    |    |--Leonardoceras parvum Flower 1968K93
    |    |--Graciloceras Flower 1943S64
    |    |    `--*G. longidomum Flower 1943S64
    |    |--Eorizoceras Flower 1943S64
    |    |    `--*E. platyceroides Flower 1943S64
    |    |--Piersaloceras Teichert 1930S64
    |    |    `--*P. gageli Teichert 1930S64
    |    `--Ringoceras Strand 1934S64
    |         `--*R. praecurvum Strand 1934S64
    |  |  |--PolyelasmoceratidaeS64
    |  |  `--OonoceratidaeS64
    |  `--+--DiestoceratidaeS64
    |     |--HemiphragmoceratidaeS64
    |     |--OncoceratidaeS64
    |     `--+--AcleistoceratidaeS64
    |        |--PoterioceratidaeS64
    |        `--KaroceratidaeS64
    |             |--Geitonoceras lucidum Zhuravleva 1974K93
    |             |--Osbornoceras Foerste 1936S64
    |             |    `--*O. swinnertoni Foerste 1936S64
    |             |--Shuranoceras Barskov 1959S64
    |             |    `--*S. dolmatovi Barskov 1959S64
    |             `--Karoceras Roussanoff 1909S64
    |                  |--*K. laminare (Barrande 1877) [=Cyrtoceras laminare]S64
    |                  `--K. typicumS64
         |--Hadoceras Strand 1934 [=Hadeoceras (l. c.)]S64
         |    `--*H. septocurvatum Strand 1934S64
         |--Rasmussenoceras Foerste 1932S64
         |    `--*R. leveannulatum (Troedsson 1926) [=Lambeoceras leveannulatum]S64
         |--Tripterocerina Foerste 1935S64
         |    |--*T. kirki Foerste 1935S64
         |    `--T. planodorsatumP68
         |--Allumettoceras Foerste 1926S64
         |    |--*A. pauquettense (Foerste 1924) [=Tripteroceras pauquettense]S64
         |    |--A. mjoesense Sweet 1958K93
         |    `--A. subequilateraleP68
         `--Tripteroceras Hyatt 1884 [=Trypteroceras (l. c.)]S64
              |--*T. hastatum (Billings 1857) [=Orthoceras hastatum]S64
              |--T. boreale Miller, Youngquist & Collinson 1954P68
              |--T. cariniferum Flower 1952P68
              |--T. scofieldi Foerste 1930P68
              `--T. xiphias (Billings 1857)K93
Oncoceratida incertae sedis:
    |--Psiaoceras Shimanskiy 1957S64
    |    `--*P. hesperis (Eichwald 1860) [=Gomphoceras hesperis]S64
    `--Tripleuroceras Hyatt 1884S64
         |--*T. archiaci (Barrande 1868) [=Orthoceras archiaci]S64
         `--T. robsoni Whiteaves 1906K93
    |--Cyrtoceratites Goldfuss 1830 (see below for synonymy)S64
    |    `--*C. flexuosus (Schlotheim 1820) [=Orthoceratites flexuosus]S64
    `--Archiacoceras Foerste 1926S64
         |--*A. subventricosus (d’Archiac & de Verneuil 1842) [=Phragmoceratites subventricosus]S64
         `--A. rarum Kuzmin 1966K93
  Antonoceras Shimanskiy 1957S64
    `--*A. balaschovi Shimanskiy 1957S64
  Eudoceras Hyatt 1884 [Eudoceratidae]S64
    `--*E. pandum (Hall 1857) [=Trochoceras (Gonioceras) pandum]S64
  Sycoceras Pictet 1854 [=Syrcoceras (l. c.)]S64
    `--*S. ficus (Roemer 1850) [=Gomphoceras ficus]S64
  Apioceras Fahrenkohl 1844 (n. d.) [=Bolboceras Fischer in Fahrenkohl 1844 non Kirby 1819]S64
    `--*A. trochoides Fahrenkohl 1844S64
  Gomphoceras Sowerby 1839 (n. d.) [=Gomphoceratites (l. c.); Gomphoceratidae]S64
    |--*G. pyriforme (Sowerby 1839) [=Orthoceras pyriforme]S64
    |--G. breviposticum Whitfield 1882P68
    |--G. calvini Cleland 1911P68
    |--G. fusiforme Whitfield 1873P68
    |--G. suboviforme Walcott 1884P68
    |--G. turbiniformeP68
    |--G. wabashensisP68
    `--G. whitfieldi Cleland 1907P68
  Nelimenia Laporte 1843 (n. d.) [=Nolimenia (l. c.)]S64
    `--*N. incognita Laporte 1843S64
  Wetherbyoceras Foerste 1926 (n. d.)S64
    |--*W. conoidale (Wetherby 1881) [=Cyrtoceras conoidale]S64
    `--W. vallandighamiP68
  Rutoceratoidea [Rutocerataceae, Rutoceratida, Rutoceratina, Ryticeracea]M13
    |  i. s.: DolerocerasM13
       |    |--Hercoceras Barrande 1865K64
       |    |    |--*H. mirum (Barrande 1854) [=Gyroceras mirum]K64
       |    |    `--H. flexum [=Trochoceras flexum]H84
       |    `--Ptenoceras Hyatt 1894TM20, K64
       |         |--*P. alatum (Barrande 1865)K64 [=Gyroceras alatumK64, Hercoceras alatumH84]
       |         `--P. nudum (Barrande 1865)TM20
            |--Tetragonoceras Whiteaves 1891K64
            |    `--*T. gracile Whiteaves 1891K64
            |--Nassauoceras Miller 1932 [=Cryptoceras d’Orbigny 1850 nec Latreille 1804 nec Barrande 1846]K64
            |    `--*N. subtuberculatum (Sandberger & Sandberger 1852)K64, K93 (see below for synonymy)
            `--Wellsoceras Flower 1945K64
                 `--*W. columbiense (Whitfield 1882) [=Gyroceras columbiense]K64
    |--Guangyuanoceroides sichuanense Lai & Zhu 1985K93
         |--G. depressum Lai & Zhu 1985K93
         `--G. planodorsum Lai & Zhu 1985K93
  Cyrtoceratidae [Cranoceratidae]K93
    |--Blakeoceras Foerste 1926K93, S64
    |    |--*B. empiricum (Barrande 1877) [=Cyrtoceras empiricum]S64
    |    `--B. llandoveri (Blake 1882)K93
    `--Cyrthoceratites d’Archiac & de Verneuil 1842K93, S64 [=Cranoceras Hyatt 1884S64]
         |--*C. depressus (Bronn 1835) [=Cyrtocera depressa, *Cranoceras depressum]S64
         |--C. alatus (Holzapfel 1895)K93
         |--‘Cyrtoceras’ hospitale [=Cranoceras hospitale]H84
         |--C. lineatus (D’Archaic & De Verneuil 1842)K93
         `--‘Cyrtoceras’ nigrum [=Cranoceras nigrum]H84
    |--Bolloceras Foerste 1926S64
    |    `--*B. rex (Barrande 1865) [=Phragmoceras rex]S64
    |--Metaphragmoceras Flower 1938K93, S64
    |    `--*M. verneuili (Barrande 1865) [=Phragmoceras verneuili]S64
    `--Paraconradoceras Foerste 1926K93, S64
         `--*P. rigescens (Barrande 1877) [=Phragmoceras rigescens]S64
    |--Irinites editus Zhuravleva 1972K93
    |--Atopoceras vodoresovi Zhuravleva 1972K93
    |--Kijoceras clarum Zhuravleva 1972K93
         |--A. anaticula Zhuravleva 1972K93
         |--A. imbellus Zhuravleva 1972K93
         |--A. longus Zhuravleva 1972K93
         `--A. verbosus Zhuravleva 1972K93
    |--Oocerina Foerste 1926 [=Oocenia (l. c.)]S64
    |    |--*O. lentigrada (Barrande 1866)S64, TM20 [=Cyrtoceras lentigradumS64]
    |    |--O. strangulatum (Barrande 1877)K93
    |    `--O. stygiale (Barrande 1877)K93
    |--Hiregiroceras costulatumKE19
    `--Moycerocanoceras sulcatumKE19
  Hedstroemoceras Foerste 1930TM20
    `--*H. haelluddenense Foerste 1930T64

Cyrtoceratites Goldfuss 1830 [=Cyrthocerus King 1844, Cyrtocera Goldfuss 1832; incl. Campulites Deshayes in Lamarck 1845, Cirthoceratites Deshayes in Cuvier 1838]S64

*Nassauoceras subtuberculatum (Sandberger & Sandberger 1852)K64, K93 [=Nautilus subtuberculatusK64, *Cryptoceras subtuberculatumH84, Temnocheilus subtuberculatusH84]

Oncoceratida [Actinosiphonata, Cyrtoceracea, Cyrtoceroidea, Equilobates, Gomphoceracea, Gomphoceroidea, Oncoceratina, Oncocerida, Oncoceroida, Oncoceroidea]

*Type species of generic name indicated


[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.

[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.

[K64] Kummel, B. 1964. Nautiloidea—Nautilida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt K. Mollusca 3. CephalopodaGeneral FeaturesEndoceratoideaActinoceratoideaNautiloideaBactritoidea pp. K383–K457. The Geological Society of America and the University of Kansas Press.

[M13] Mutvei, H. 2013. Characterization of nautiloid orders Ellesmerocerida, Oncocerida, Tarphycerida, Discosorida and Ascocerida: new superorder Multiceratoidea. GFF 135 (2): 171–183.

[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. CephalopodaGeneral FeaturesEndoceratoideaActinoceratoideaNautiloideaBactritoidea pp. K277–K319. The Geological Society of America and the University of Kansas Press.

[T64] Teichert, C. 1964. Doubtful taxa. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt K. Mollusca 3. Cephalopoda—General Features—Endoceratoidea—Actinoceratoidea—Nautiloidea—Bactritoidea pp. K484–K490. The Geological Society of America and the University of Kansas Press.

[TM20] Turek, V., & Š. Manda. 2020. Discontinuous, asymmetric and irregular colour patterns in Silurian oncocerids (Nautiloidea) with cyrtoconic shells. Bulletin of Geosciences 95 (3): 333–367.

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