Oncocerida

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

Belongs within: Cephalopoda.
Contains: Oncoceratidae, Valcouroceratidae.

The Oncocerida 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.

<==Oncocerida (see below for synonymy)
    |  i. s.: Tripleuroceratidae S64
    |           |--Tripleuroceras Hyatt 1884 S64
    |           |    `--*T. archiaci (Barrande 1868) [=Orthoceras archiaci] S64
    |           `--Psiaoceras Shimanskiy 1957 S64
    |                `--*P. hesperis (Eichwald 1860) [=Gomphoceras hesperis] S64
    |         Archiacoceratidae S64
    |           |--Archiacoceras Foerste 1926 S64
    |           |    `--*A. subventricosus (d’Archiac & de Verneuil 1842) [=Phragmoceratites subventricosus] S64
    |           |--Cyrtoceratites Goldfuss 1830 (see below for synonymy) S64
    |           |    `--*C. flexuosus (Schlotheim 1820) [=Orthoceratites flexuosus] S64
    |           `--Devonocheilus Shimanskiy 1962 S64
    |                `--*D. timanicus (Holzapfel 1899) [=Phragmoceras timanicum] S64
    |         Antonoceras Shimanskiy 1957 S64
    |           `--*A. balaschovi Shimanskiy 1957 S64
    |         Eudoceras Hyatt 1884 S64
    |           `--*E. pandum (Hall 1857) [=Trochoceras (Gonioceras) pandum] S64
    |         Pachtoceras Foerste 1926 S64
    |           `--*P. rotundum (Pacht 1858) [=Gomphoceras rotundum] 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 1844 S64
    |         Gomphoceras Sowerby 1839 (n. d.) [=Gomphoceratites (l. c.); Gomphoceratidae] S64
    |           |--*G. pyriforme (Sowerby 1839) [=Orthoceras pyriforme] S64
    |           |--G. breviposticum Whitfield 1882 P68
    |           |--G. calvini Cleland 1911 P68
    |           |--G. fusiforme Whitfield 1873 P68
    |           |--G. suboviforme Walcott 1884 P68
    |           |--G. turbiniforme P68
    |           |--G. wabashensis P68
    |           `--G. whitfieldi Cleland 1907 P68
    |         Nelimenia Laporte 1843 (n. d.) [=Nolimenia (l. c.)] S64
    |           `--*N. incognita Laporte 1843 S64
    |         Pictetoceras Foerste 1926 (n. d.) S64
    |           `--*P. eichwaldi (de Verneuil 1845) [=Gomphoceras eichwaldi] S64
    |         Wetherbyoceras Foerste 1926 (n. d.) S64
    |           |--*W. conoidale (Wetherby 1881) [=Cyrtoceras conoidale] S64
    |           `--W. vallandighami P68
    |--Oncoceratidae S64
    |--Graciloceratidae S64
    |    |--Graciloceras Flower 1943 S64
    |    |    `--*G. longidomum Flower 1943 S64
    |    |--Eorizoceras Flower 1943 S64
    |    |    `--*E. platyceroides Flower 1943 S64
    |    |--Piersaloceras Teichert 1930 S64
    |    |    `--*P. gageli Teichert 1930 S64
    |    `--Ringoceras Strand 1934 S64
    |         `--*R. praecurvum Strand 1934 S64
    |--+--Valcouroceratidae S64
    |  `--Jovellaniidae S64
    |       |--Jovellania Bayle 1879 [=Jovelliania (l. c.); incl. Trigonodema Laporte 1843 (nom. rej. prop.)] S64
    |       |    `--*J. buchi (de Verneuil 1850) [=Orthoceratites buchi] S64
    |       |--Herkimeroceras Foerste 1926 S64
    |       |    `--*H. subrectum (Hall 1859) [=Cyrtoceras subrectum] S64
    |       |--Laumontoceras Foerste 1926 S64
    |       |    `--*L. laumonti (Barrande 1866) [=Orthoceras laumonti] S64
    |       |--Mixosiphonoceras Hyatt 1900 S64
    |       |    `--*M. desolatum (Barrande 1877) [=Cyrtoceras desolatum] S64
    |       `--Projovellania Hyatt in Zittel 1900 S64
    |            `--*P. athleta (Barrande 1877) [=Cyrtoceras athleta] S64
    `--Tripteroceratidae S64
         |--Hadoceras Strand 1934 [=Hadeoceras (l. c.)] S64
         |    `--*H. septocurvatum Strand 1934 S64
         |--Rasmussenoceras Foerste 1932 S64
         |    `--*R. leveannulatum (Troedsson 1926) [=Lambeoceras leveannulatum] S64
         |--Allumettoceras Foerste 1926 S64
         |    |--*A. pauquettense (Foerste 1924) [=Tripteroceras pauquettense] S64
         |    `--A. subequilaterale P68
         |--Tripterocerina Foerste 1935 S64
         |    |--*T. kirki Foerste 1935 S64
         |    `--T. planodorsatum P68
         `--Tripteroceras Hyatt 1884 [=Trypteroceras (l. c.)] S64
              |--*T. hastatum (Billings 1857) [=Orthoceras hastatum] S64
              |--T. boreale Miller, Youngquist & Collinson 1954 P68
              |--T. cariniferum Flower 1952 P68
              `--T. scofieldi Foerste 1930 P68

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

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

*Type species of generic name indicated

REFERENCES

[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 Treatise on Invertebrate Paleontology pt. K. Mollusca 3. Cephalopoda – General Features – Endoceratoidea – Actinoceratoidea – Nautiloidea – Bactritoidea (R. C. Moore, ed.) pp. K277-K319. The Geological Society of America and the University of Kansas Press.