Trigonoceratidae

Lateral and ventral views of Rineceras propinquum, from Kummel (1964).

Belongs within: Nautilida.

Mostly known from the Lower Carboniferous (though a single genus, Apogonoceras, survived into the Lower Permian), the Trigonoceratidae were a morphologically diverse family of nautilid cephalopods. As well as more typical evolute forms, the Trigonoceratidae also included some genera (such as Choteauoceras and Rineceras) in which the shells were loosely coiled with successive whorls not remaining in contact with each other (Kummel 1964).

Characteristics (from Kummel 1964): Loosely coiled to evolute, with oval to subquadratic, depressed to compressed whorl sections, generally bearing longitundinal ridges that may decrease with growth. Suture usually only slightly sinuous. Siphuncle small, central, orthochoanitic.

<==Trigonoceratidae (see below for synonymy)
    |--Mesochasmoceras Foord 1900 H99
    |    `--*M. latidorsatum (M’Coy 1844) [=Nautilus (Discites) latidorsatus] H99
    |--Lispoceras Hyatt 1893 K64
    |    `--*L. trivolve Hyatt 1893 K64
    |--Leuroceras Hyatt 1893 K64
    |    `--*L. aplanatum Hyatt 1893 K64
    |--Diodoceras Hyatt in Zittel 1900 K64
    |    `--*D. avonense (Dawson 1868) [=Nautilus avonensis] K64
    |--Apogonoceras Ruzhentsev & Shimanskiy 1954 K64
    |    `--*A. remotum Ruzhentsev & Shimanskiy 1954 K64
    |--Chouteauoceras Miller & Garner 1953 K64
    |    `--*C. americanum (Miller & Furnish 1939) [=Rineceras americanum] K64
    |--Pararineceras Turner 1954 K64
    |    `--*P. luidi (Fleming 1828) [=Nautilus luidi] K64
    |--Discitoceras Hyatt 1884 H99 [incl. Discites M’Coy 1844 nec Schlotheim 1813 nec de Haan 1825 K64]
    |    |--*D. costellatum (M’Coy 1844) [=Nautilus (Discites) costellatus, Discitoceras costellatus (l. c.)] H99
    |    `--D. texanum Miller & Youngquist 1948 P68
    |--Rineceras Hyatt 1893 [=Rhineceras Hyatt in Zittel 1900] K64
    |    |--*R. propinquum (de Koninck 1880) [=Gyroceras propinquum] K64
    |    `--R. digonum P68
    |--Trigonoceras M’Coy 1844 H99 [incl. Nautiloceras d’Orbigny 1849 K64]
    |    |--*T. paradoxicum (Sowerby 1825) [=Orthocera paradoxica, Orthoceras (Trigonoceras) paradoxicum] H99
    |    |--T. asselberghsi Maillieux 1925 H99
    |    `--T. visetense Maillieux 1925 H99
    |--Subclymenia d’Orbigny 1849 K64
    |    |--S. evoluta (Phillips 1836) [=Goniatites evolutus] K64
    |    |--S. gibbosa K64
    |    `--S. occulata K64
    |--Stroboceras Hyatt 1884 K64
    |    |--*S. hartii (Dawson 1868) [=Gyroceras hartii] K64
    |    |--S. bisulcatum K64
    |    |--S. crispum Gordon 1957 P68
    |    `--S. stygiale K64
    |--Thrincoceras Hyatt 1893 H99 [incl. Neothrincoceras Ruzhentsev & Shimanskiy 1954 K64]
    |    |--*T. depressum Hyatt 1893 H99
    |    |--T. hibernicum (Foord 1891) [=Gyroceras hibernicum, Rineceras hibernicum] H99
    |    |--T. hyatti Foord 1900 H99
    |    `--T. kentuckiense Hyatt 1893 H99
    |--Maccoyoceras Miller, Dunbar & Condra 1933 H99
    |    |--*M. discors (M’Coy 1844) [=Nautilus (Discites) discors, Discitoceras discors] H99
    |    |--M. discoidale (Winchell 1862) H99
    |    |--M. leveilleanum (de Koninck 1844) (see below for synonymy) H99
    |    |--M. oppaviense (Patteisky 1930) H99
    |    `--M. wrightii (Foord 1900) [=Discitoceras wrightii] H99
    |--Aphelaeceras Hyatt 1884 H99 [=Apheleceras (l. c.) K64]
    |    |--*A. disciformis (Meek & Worthen 1873) [=Nautilus (Discites) disciformis] H99
    |    |--A. arkansanum Gordon 1964 H99
    |    |--A. difficile (de Koninck 1878) H99
    |    |--A. discoideum (de Konick 1878) H99
    |    |--A. discus (Sowerby 1813) H99
    |    |--A. exaratum (de Koninck 1878) H99
    |    |--A. hibernicum (Foord & Crick 1893) [=Discites hibernicus, Apheleceras (l. c.) hibernicus] H99
    |    |--A. mosquense Tzwetaev 1888 H99
    |    |--A. mutabile (M’Coy 1844) (see below for synonymy) H99
    |    `--A. trochlea (M’Coy 1844) [=Nautilus (Discites) trochlea, Apheleceras (l. c.) trochlea] H99
    |--Epistroboceras Turner 1954 H99
    |    |--*E. stubblefieldi Turner 1954 H99
    |    |--E. chancharense Shimansky 1967 H99
    |    |--E. crassum (Foord 1900) [=Stroboceras crassum] H99
    |    |--E. gracile Shimansky 1967 H99
    |    |--E. kathleenae Ramsbottom & Moore 1961 H99
    |    |--E. phillipsianum (Orbigny 1850) H99
    |    |--E. sulcatum (Sowerby 1826) H99 (see below for synonymy)
    |    |    |--E. s. sulcatum H99
    |    |    `--E. s. castletonense Turner 1965 H99
    |    `--E. sulcifer (Léveillé 1835) H99
    `--Vestinautilus Ryckholt 1852 H99 [incl. Triboloceras Hyatt in Zittel 1884 K64]
         |--*V. koninckii (Orbigny 1850) [=Nautilus koninckii] H99
         |--V. altidorsalis Winchell 1862 H99
         |--V. biangulatus (Sowerby 1825) H99
         |--V. cariniferus (Sowerby 1824) (see below for synonymy) H99
         |--‘Triboloceras’ digonum P68
         |--V. formosus (Foord 1900) (see below for synonymy) H99
         |--V. multicarinatus (Sowerby 1825) (see below for synonymy) H99
         |--V. paucicarinatus (Foord 1900) [=Coelonautilus paucicarinatus] H99
         |--V. pinguis (de Koninck 1843) [=Nautilus pinguis, Coelonautilus pinguis] H99
         |--V. semiglaber Foord 1900 H99
         `--V. semiplicatus (Foord 1900) H99

Aphelaeceras mutabile (M’Coy 1844) [=Nautilus (Discites) mutabilis, Aphelaeceras mutabilis (l. c.), Apheleceras (l. c.) mutabile] H99

Epistroboceras sulcatum (Sowerby 1826) H99 [=Nautilus sulcatus H99, Discitoceras sulcatum K64, N. (Discites) sulcatus H99, Stroboceras sulcatum H99]

Maccoyoceras leveilleanum (de Koninck 1844) [=Nautilus leveilleanus, Discites leveilleanus, Discitoceras leveilleanum] H99

Trigonoceratidae [Aphelaeceratinae, Neothrincoceratidae, Rhineceratidae, Rineceratidae, Subclymeniidae, Thrincoceratidae, Tribolocerataceae, Triboloceratidae]

Vestinautilus cariniferus (Sowerby 1824) [=Nautilus cariniferus, Coelonautilus cariniferus, N. (Temnocheilus) cariniferus] H99

Vestinautilus formosus (Foord 1900) [=Triboloceras formosum; incl. Nautilus (Temnocheilus) crenatus M’Coy 1844 (n. d.)] H99

Vestinautilus multicarinatus (Sowerby 1825) [=Nautilus multicarinatus, Coelonautilus multicarinatus; incl. N. (Temnocheilus) porcatus M’Coy 1844] H99

*Type species of generic name indicated

REFERENCES

[H99] Histon, K. 1999. A revision of A. H. Foord’s monograph of Irish Carboniferous nautiloid cephalopods (1897-1901). Part 2. Monograph of the Palaeontographical Society 153: 63-129.

[K64] Kummel, B. 1964. Nautiloidea – Nautilida. In Treatise on Invertebrate Paleontology pt. K. Mollusca 3. Cephalopoda – General Features – Endoceratoidea – Actinoceratoidea – Nautiloidea – Bactritoidea (R. C. Moore, ed.) pp. K383-K457. The Geological Society of America and the University of Kansas Press.

[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.