Tarphyceratida

Discoceras antiquissimum, from here.

Belongs within: Nautilosiphonata.

The Lower Ordovician to Upper Devonian Tarphycerida were the earliest lineage of coiled cephalopods. In a number of forms, the later whorls become separated from the older part of the shell; in the family Lituitidae the later part of the shell becomes straight and much larger than the coiled part. The siphuncle is subventral in earlier parts of the shell, but moves during growth depending on the family: in Tarphyceratidae and Estonioceratidae it remains ventral at maturity, in Trocholitidae it becomes dorsal, and in Lituitidae and Ophioceras it becomes subcentral (Furnish & Glenister 1964).

When is a cephalopod like a snake?
Published 31 October 2008
The tarphycerid Lituites lituus. Photo from here.

When its a snakestone.

Just a quick post on tarphycerids today—haven’t much time. The Tarphycerida were the earliest group of cephalopods to develop a coiled shell, back in the lower Ordovician. Sweet et al. (1964) regarded tarphycerids as sharing a common ancestor in the lower Ordovician Bassleroceratidae with the Oncocerida, the lineage ancestral to modern nautilids. Though tarphycerids are therefore more closely related to nautilids than to coleoids (and therefore, unlike the other Palaeozoic cephalopods I’ve covered so far, have a case to actually be regarded as nautiloids), the fact that the earliest oncocerids were not coiled (Sweet 1964a) indicates that the coiled form was independently derived in tarphycerids from nautilids. A few tarphycerid lineages later became more loosely coiled, or uncoiled.

Campbelloceras, a more typical tarphycerid. Note the significant size of the body chamber compared to earlier chambers. From Palaeos.com.

Most tarphycerids were more or less evolute. Closely coiled cephalopod shells can be described as evolute, involute or convolute, though these aren’t distinct forms so much as lines on a spectrum. In involute forms, the successive whorls of the shell overlap and cover the earlier whorls to some degree. This is taken to the extreme in convolute forms such as modern Nautilus in which the later whorls entirely conceal the older whorls. In evolute forms, however, the successive whorls lie alongside each other and remain clearly visible. There seems to have been a repeated tendency for evolute forms to be replaced by involute forms – I’m guessing because the involute arrangement was more sturdy and robust. Evolute shells are described as ‘serpenticone’, which refers to an old English belief that such shells were the petrified remains of coiled snakes. Indeed, it was not uncommon for coiled cephalopod fossils to be sold as ‘snakestones’ (supposedly protecting against snakebite) with carved snake heads attached to them.

A specimen of the ammonite Dactylioceras commune, modified into a snakestone. Photo from here.

One tarphycerid genus, Lituites, was one of the earliest fossil cephalopods recognised, and though officially published by Bertrand in 1763, Bertrand was merely validating a name that pre-dated Linnaeus (Furnish & Glenister 1964). Lituitidae started life as coiled shells, but soon changed their growth pattern and grew in a straight line, with the straight segment of shell far larger than the coiled section—lituitids might be up to a foot in length, with the coiled section less than an inch across. While most tarphycerid families were widespread (albeit uncommon), lituitids are only known from northern Europe (and mostly from erratic boulders, which are an absolute bugger to place stratigraphically).

Many tarphycerids showed changes in growth habit through their life. The siphuncle often changed in position—all tarphycerids had ventral siphuncles when young, but for many species they became dorsal with age. Juvenile tarphycerids had standard round apertures, but in many species the aperture changed significantly in form at maturity, becoming contracted by ingrowing lobes of the shell with deep hyponomic and ocular sinuses. Whether and how this change in aperture form was reflected by any change in soft-body morphology can, of course, only be speculated upon. It is worth noting, as well, that the mature body chamber was often spectacularly long—in the family Ophidioceratidae, it may occupy more than an entire whorl of the shell. Again, in the absence of soft-body fossils there is no way of knowing whether the adult body was similarly long, or whether the animal was shorter and able to retreat deep into its shell.

Tarphycerids survived into the mid-Devonian—Sweet (1964b) separated the lineage including all later forms as the order Barrandeocerida, but all more recent authors seem to include the barrandeocerids in the Tarphycerida* (e.g. Turek 2008). A number of barranderocerids became non-planar coilers (torticones), adopting a more gastropod-like form. Because non-planar coils would not have had such a centred buoyancy distribution compared to planar forms, these species would have probably been benthic in their lifestyle. The tarphycerids disappeared at about the same time as the ecologically similar nautilids and ammonoids were diversifying.

*The concept of paraphyletic taxa in a phylogeny-based classification is a bit like the concept of God in a secular society. People may not actually have anything against the idea, they may argue vociferously for the retention of the idea, but as time goes by they just refer to the idea less and less, and eventually the realisation dawns that there’s just no real practical point in hanging on to it.

Systematics of Tarphyceratida

Characters (from Furnish & Glenister 1964): Coiled conchs with varying degrees of adoral divergence; septa simple, siphuncle unstable in position; septal necks orthochoanitic, connecting rings layered; aperture characterised by prominent hyponomic sinus; fully mature aperture commonly modified.

<==Tarphyceratida [Tarphyceratina, Tarphycerida]KE19
    |--Ophioceras Barrande 1865 [=Euophioceras Miller 1932, Ophidioceras Barrande 1867; Ophidioceratidae, Ophioceratidae]FG64
    |    |--*O. simplex (Barrande 1865) [=Lituites (*Ophioceras) simplex, *Euophioceras simplex]FG64
    |    |--O. reticulatum Angelin in Angelin & Lindström 1880K93
    |    |--O. rota Lindström 1890K93
    |    |--O. rudens Barrande 1865K93
    |    `--‘Ophidioceras’ wilmingtonense Foerste 1925P68
    |--Discoceras Barrande 1867FG64 (see below for synonymy)
    |    |--*D. antiquissimum (Eichwald 1842) [=Clymenia antiquissima]FG64
    |    |--D. amtjaernensese Kröger & Aubrechtová 2019TM20
    |    |--D. angulatum (Saemann 1852)FG64 [=Lituites angulatusFG64, *Schroederoceras angulatumFG64, Trocholites angulatusH84]
    |    |--D. borealeFG64
    |    |--D. canadenseP68
    |    |--‘Schroederoceras’ cassinenseP68
    |    |--‘Schroederoceras’ eatoniP68
    |    `--D. eurasiaticum Frech 1911 [=*Eurasiaticoceras eurasiaticum]FG64
    |--PlectroceratidaeK93
    |    |--Avilionella Flower 1952K93, S64
    |    |    `--*A. multicameratum (Ruedemann 1906)S64, K93 [=Tarphyceras multicameratumK93]
    |    |--Laureloceras Flower 1943K93, S64
    |    |    `--*L. cumingsi Flower 1943S64
    |    `--Plectoceras Hyatt 1884 [incl. Metaplectoceras Foerste 1935]S64
    |         |--*P. jason (Billings 1859) [=Nautilus jason]S64
    |         |--P. foersteiS64
    |         `--‘Metaplectoceras’ landerense Foerste 1935P68
    |--ApsidoceratidaeS64
    |    |--Bodoceras torticoni Frey 1982K93
    |    |--Chidleyenoceras Shimizu & Obata 1935S64
    |    |    `--*C. chidleyense (Foerste 1928) [=Eurystomites chidleyense]S64
    |    |--Deckeroceras Foerste 1935S64
    |    |    `--*D. adaense Foerste 1935S64
    |    |--Fremontoceras Foerste 1935S64
    |    |    |--*F. loperi Foerste 1935S64
    |    |    `--F. jewetti Flower 1947K93
    |    |--Apsidoceras Hyatt 1884S64
    |    |    |--*A. magnificum (Billings 1857) [=Gyroceras (Lituites) magnificum]S64
    |    |    |--A. elegansS64
    |    |    `--A. montrealense Flower 1943K93
    |    |--Charactocerina Foerste 1935S64
    |    |    |--*C. plicata (Whiteaves 1896) [=Eurystomites plicatus]S64
    |    |    |--C. eximiaS64
    |    |    |--C. kirki Foerste 1935P68
    |    |    `--C. multicamerata Foerste 1935P68
    |    |--Wilsonoceras Foerste 1929S64
    |    |    |--*W. mccharlesi (Whiteaves 1890) [=Trochoceras mccharlesi]S64
    |    |    |--W. bighornenseP68
    |    |    |--W. brevicameratum Foerste 1935P68
    |    |    `--W. squawcreekenseS64
    |    `--Charactoceras Foerste 1924S64
    |         |--*C. baeri (Meek & Worthen 1865) [=Trochoceras baeri]S64
    |         |--C. canyonense Foerste 1935P68
    |         |--C. kallholnense Frey 1982K93
    |         |--C. raettvikense Frey 1982K93
    |         |--C. schucherti Foerste 1928P68
    |         |--C. suecicum Frey 1982K93
    |         `--C. triangulum Frey 1982K93
    |--EstonioceratidaeFG64
    |    |--Pakrioceras holmi Stumbur & Mutvei 1983K93
    |    |--Aethoceras Teichert & Glenister 1954 [incl. Aetococeras Balashov 1962]FG64
    |    |    `--*A. caurus Teichert & Glenister 1954FG64
    |    |--Alaskoceras Miller & Kummel 1945FG64
    |    |    `--*A. sewardense (Flower 1941) [=Plectoceras sewardense]FG64
    |    |--Clytoceras Ulrich, Foerste et al. 1942FG64
    |    |    `--*C. capax Ulrich, Foerste et al. 1942FG64
    |    |--Eichwaldoceras Balashov 1955FG64
    |    |    `--*E. volchovense Balashov 1955FG64
    |    |--Tragoceras Remelé 1890 [=Aegoceras Remelé 1880 non Waagen 1869, Planctoceras Schröder 1891]FG64
    |    |    `--*T. falcatum (von Schlotheim 1820) (see below for synonymy)FG64
    |    |--Shumardoceras Ulrich & Foerste 1936FG64
    |    |    |--*S. complanatum (Shumard 1863) [=Lituites complanata]FG64
    |    |    |--S. fragile Ulrich, Foerste et al. 1942P68
    |    |    `--S. taneyense Ulrich, Foerste et al. 1942P68
    |    |--Pycnoceras Hyatt 1894 [=Pyrenoceras (l. c.)]FG64
    |    |    |--*P. apertum Hyatt 1894FG64
    |    |    |--P. clausum Ulrich, Foerste et al. 1942P68
    |    |    `--P. rotundatum Ulrich, Foerste et al. 1942P68
    |    |--Estonioceras Noetling 1883 [incl. Falcilituites Remelé 1886]FG64
    |    |    |--*E. lamellosum (Hisinger 1837) [=Lituites lamellosus]FG64
    |    |    |--E. arienseFG64
    |    |    |--‘Lituites’ decheni Remelé 1880 [=*Falcilituites decheni]FG64
    |    |    |--E. imperfectumM13
    |    |    |--E. impressumKE19
    |    |    `--E. perforatum Schröder 1888KE19
    |    `--Aphetoceras Hyatt 1894FG64
    |         |--*A. americanum Hyatt 1894FG64
    |         |--A. attenuatumFG64
    |         |--A. evolution Ulrich, Foerste et al. 1942P68
    |         |--A. oderi Ulrich, Foerste et al. 1942P68
    |         |--A. ruedemanni Ulrich, Foerste et al. 1942P68
    |         `--A. subcostulatum Ulrich, Foerste et al. 1942P68
    |--Trocholitidae [Beekmanoceratidae, Trocholithidae]FG64
    |    |--PlectolitesFB04
    |    |--Arkoceras Ulrich, Foerste et al. 1942 [=Arcoceras (l. c.)]FG64
    |    |    `--*A. exiguum Ulrich, Foerste et al. 1942FG64
    |    |--Beekmanoceras Ulrich & Foerste 1936FG64
    |    |    `--*B. priscum (Ruedemann 1906) [=Cyrtendoceras priscum]FG64
    |    |--Graftonoceras Foerste 1925FG64
    |    |    `--*G. graftonense (Meek & Worthen 1870) [=Lituites graftonensis]FG64
    |    |--Hardmanoceras Teichert & Glenister 1952FG64
    |    |    `--*H. lobatum Teichert & Glenister 1952FG64
    |    |--Jasperoceras Ulrich, Foerste et al. 1942FG64
    |    |    `--*J. costatum Ulrich, Foerste et al. 1942FG64
    |    |--Litoceras Hyatt 1883 [=Litoceres (l. c.); incl. Litoceras Hyatt 1894 non Hyatt 1883]FG64
    |    |    |--*L. versutum (Billings 1865) [=Nautilus versutus]FG64
    |    |    `--*L. (sensu Hyatt 1894) whiteavesi Hyatt 1894FG64
    |    |--Curtoceras Ulrich, Foerste et al. 1942FG64
    |    |    |--*C. eatoni (Whitfield 1886) [=Lituites eatoni]FG64
    |    |    |--C. cassinense (Whitfield 1886)K93
    |    |    `--C. internastriatum (Whitfield 1886)K93
    |    |--Wichitoceras Ulrich, Foerste et al. 1942FG64
    |    |    |--*W. compressum Ulrich, Foerste et al. 1942FG64
    |    |    |--W. chadwickense Ulrich, Foerste et al. 1942P68
    |    |    |--W. crassum Ulrich, Foerste et al. 1942P68
    |    |    |--W. decipiens Ulrich, Foerste et al. 1942P68
    |    |    `--W. naylorense Ulrich, Foerste et al. 1942P68
    |    |--Trocholitoceras Hyatt 1894FG64
    |    |    |--*T. walcotti Hyatt 1894FG64
    |    |    |--T. bevani Ulrich, Foerste et al. 1942P68
    |    |    |--T. juvenicostatum Ulrich, Foerste et al. 1942P68
    |    |    |--T. latum Ulrich, Foerste et al. 1942P68
    |    |    `--T. philipsburgense Ulrich, Foerste et al. 1942P68
    |    `--Trocholites Conrad 1838 [=Trocholithes (l. c.); incl. Palaeoclymenia Remelé 1881, Palaeonautilus Remelé 1880]FG64
    |         |--*T. ammonius Conrad 1838FG64
    |         |    |--T. a. ammoniusP68
    |         |    `--T. a. major Ruedemann 1926P68
    |         |--T. contractusKE19
    |         |--*Palaeonautilus’ hospes Remelé 1880FG64
    |         |--T. orbisKE19
    |         |--T. planorbiformis Conrad 1842 [=*Palaeoclymenia planorbiformis]FG64
    |         |--T. trapezoidale (Lossen 1860) [=Lituites trapezoidale]H84
    |         `--T. undatus [=Lituites undatus]H84
    `--TarphyceratidaeFG64
         |--Moreauoceras Cullison 1944FG64
         |    `--*M. milleri Cullison 1944FG64
         |--Pilotoceras Cullison 1944FG64
         |    `--*P. brunei Cullison 1944FG64
         |--Seelyoceras Ulrich & Foerste 1936FG64
         |    `--*S. raei (Whitfield 1889) [=Cyrtoceras raei]FG64
         |--Cycloplectoceras Ulrich, Foerste et al. 1942FG64
         |    |--*C. miseri Ulrich, Foerste et al. 1942FG64
         |    `--C. funatum Ulrich, Foerste et al. 1942P68
         |--Eurystomites Schröder 1891FG64
         |    |--*E. kelloggi (Whitfield 1886) [=Nautilus kelloggi]FG64
         |    |--E. avensis Ulrich, Foerste et al. 1942P68
         |    |--E. bolarensis Ulrich, Foerste et al. 1942P68
         |    `--E. rotundus Hyatt 1894P68
         |--‘Pionoceras’ Ulrich, Foerste et al. 1942 non Lissajous 1923FG64
         |    |--*P. pomponium (Billings 1862) [=Nautilus pomponius]FG64
         |    |--P. smithvillense Ulrich, Foerste et al. 1942P68
         |    |--P. swartzi Ulrich, Foerste et al. 1942P68
         |    `--P. vokesi Ulrich, Foerste et al. 1942P68
         |--Campbelloceras Ulrich & Foerste 1936FG64
         |    |--*C. virginianum (Hyatt 1894) [=Eurystomites virginiana]FG64
         |    |--C. brevicameratum Ulrich, Foerste et al. 1942P68
         |    |--C. hyatti Ulrich, Foerste et al. 1942P68
         |    `--C. rotundumFG64
         |--Tarphyceras Hyatt 1894 [incl. Remeleceras Hyatt 1894 (n. d.), Remeleoceras Hyatt in Zittel 1900]FG64
         |    |--*T. prematurum Hyatt 1894FG64
         |    |--T. aucoiniFG64
         |    |--T. chadwickense Ulrich, Foerste et al. 1942P68
         |    |--T. champlainenseP68
         |    |--*Remeleceras’ depressum Hyatt 1894 (n. d.)T64
         |    |--T. macdonaldi Hyatt 1894P68
         |    |--T. morkokense Balashov 1962K93
         |    `--‘Remeleoceras’ subquadrangularisG31
         `--Centrotarphyceras Ulrich & Foerste 1936FG64
              |--*C. seelyi (Whitfield 1886) [=Lituites seelyi]FG64
              |--C. alpheusi Ulrich, Foerste et al. 1942P68
              |--C. bridgei Ulrich, Foerste et al. 1942P68
              |--C. macdonaldiP68
              |--C. powersi Ulrich, Foerste et al. 1942P68
              |--C. subundosum Ulrich, Foerste et al. 1942P68
              `--C. vellvillense Ulrich, Foerste et al. 1942P68

Discoceras Barrande 1867FG64 [incl. Eurasiaticoceras Shimizu & Obata 1935FG64, Schroederoceras Hyatt 1894FG64; DiscoceratidaeM13]

*Tragoceras falcatum (von Schlotheim 1820) [=Orthoceratites falcatus, *Aegoceras falcatum, *Planctoceras falcatum]FG64

*Type species of generic name indicated

References

[FB04] Frey, R. C., M. S. Beresi, D. H. Evans, A. H. King & I. G. Percival. 2004. Nautiloid cephalopods. In: Webby, B. D., F. Paris, M. L. Droser & I. G. Percival (eds) The Great Ordovician Biodiversification Event pp. 209–213. Columbia University Press.

[FG64] Furnish, W. M., & B. F. Glenister. 1964. Nautiloidea—Tarphycerida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt K. Mollusca 3. Cephalopoda—General Features—Endoceratoidea—Actinoceratoidea—Nautiloidea—Bactritoidea pp. K343–K368. The Geological Society of America and the University of Kansas Press.

[G31] Grabau, A. W. 1931. The Permian of Mongolia: A report on the Permian fauna of the Jisu Honguer limestone of Mongolia and its relations to the Permian of other parts of the world. American Museum of Natural History: New York.

[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.

[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.

Sweet, W. C. 1964a. 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.

[S64] Sweet, W. C. 1964b. Nautiloidea—Barrandeocerida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt K. Mollusca 3. CephalopodaGeneral FeaturesEndoceratoideaActinoceratoideaNautiloideaBactritoidea pp. K368–K382. The Geological Society of America and the University of Kansas Press.

Sweet, W. C., C. Teichert & B. Kummel. 1964. Phylogeny and evolution. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt K. Mollusca 3. CephalopodaGeneral FeaturesEndoceratoideaActinoceratoideaNautiloideaBactritoidea pp. K106–K114. 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.

Turek, V. 2008. Boionautilus gen. nov. from the Silurian of Europe and North Africa (Nautiloidea, Tarphycerida). Bulletin of Geosciences 83 (2): 141–152.

[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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