Tetragonites epigonus, from Wright et al. (1996).

Belongs within: Lytoceratida.

The Tetragonitidae are a lineage of lytoceratidan ammonites known from the Upper Aptian to the Maastrichtian of the Cretaceous (Wright et al. 1996).

Characters (from Wright et al. 1996): Whorl section rectangular or trapezoidal in early whorls, sometimes depressed; usually smooth, occasionally lirate or striate; constrictions on internal mold strongly prorsiradiate but usually recurved across venter, corresponding with collars on outer shell surface; major saddles of suture irregularly trifid, several auxiliary saddles present, two or more saddles in internal suture; dorsal lobe may form septal lobe on preceding septum.

<==Tetragonitidae [Protetragonitidae]EK02
| i. s.: Protetragonites Hyatt 1900EK02 [incl. Hemitetragonites Spath 1927WCH96, Leptotetragonites Spath 1927WCH96]
| |--*P. quadrisulcatus (Orbigny 1841) [=Ammonites quadrisulcatus]WCH96
| |--‘Hemitetragonites’ crebrisulcatusP93
| `--‘Hemitetragonites’ strangulatusP93
| |--Gabbioceras Hyatt 1900WCH96
| | `--G. angulatum Anderson 1902 [incl. Ammonites batesi Gabb 1869 non Trask 1855, *G. batesi]WCH96
| `--Jauberticeras Jacob 1907 [=Jaubertella Jacob 1908]WCH96
| `--*J. jaubertianus (Orbigny 1850) [=Ammonites jaubertianus, *Jaubertella jaubertiana]WCH96
|--Saghalinites Wright & Matsumoto 1954WCH96
| `--*S. cala (Forbes 1846) [=Ammonites cala]WCH96
|--Pseudophyllites Kossmat 1895WCH96
| `--*P. indra (Forbes 1846) [=Ammonites indra]WCH96
|--Parajaubertella Matsumoto 1942WCH96
| `--*P. kawakitana Matsumoto 1942WCH96
|--‘Takahashia’ Matsumoto 1984 nec Cockerell 1896 nec Ananthakrishnan 1970WCH96
| `--*T. eureka Matsumoto 1984WCH96
`--Tetragonites Kossmat 1895EK02 (see below for synonymy)
| i. s.: *Tingriceras’ chanaense Chao 1976WCH96
| T. kingianus Kossmat 1895 [=*Eoepigoniceras kingianum]WCH96
| T. popetensisTLY03
| *Neoepigoniceras’ schmidti Shimizu 1935WCH96
| T. subbeticusWK81
|--T. (Tetragonites)WCH96
| |--*T. (T.) timotheanus (Pictet 1847) [=Ammonites timotheanus]WCH96
| `--T. (T.) epigonus (Kossmat 1895) [=Lytoceras (T.) epigonus, *Epigoniceras epigonus]WCH96
`--T. (Carinites Wiedmann 1973)WCH96
`--T. (*C.) spathi Fabre 1940WCH96

Tetragonites Kossmat 1895EK02 [incl. Eoepigoniceras Shimizu 1935 (n. n.)WCH96, Epigoniceras Spath 1925WCH96, Neoepigoniceras Shimizu 1935 (n. n.)WCH96, Tingriceras Chao 1976WCH96]

*Type species of generic name indicated


[EK02] Engeser, T., & H. Keupp. 2002. Phylogeny of the aptychi-possessing Neoammonoidea (Aptychophora nov., Cephalopoda). Lethaia 35: 79–96.

[P93] Page, K. N. 1993. Mollusca: Cephalopoda (Ammonoidea: Phylloceratina, Lytoceratina, Ammonitina and Ancyloceratina). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 213–227. Chapman & Hall: London.

[TLY03] Tanabe, K., N. H. Landman & Y. Yoshioka. 2003. Intra- and interspecific variation in the early internal shell features of some Cretaceous ammonoids. Journal of Paleontology 77 (5): 876–887.

[WK81] Wiedmann, J., & J. Kullmann. 1981. Ammonoid sutures in ontogeny and phylogeny. In: House, M. R., & J. R. Senior (eds) The Ammonoidea: The evolution, classification, mode of life and geological usefulness of a major fossil group pp. 215–255. Academic Press.

[WCH96] Wright, C. W., J. H. Calloman & M. K. Howarth. 1996. Treatise on Invertebrate Paleontology pt L. Mollusca 4, revised vol. 4. Cretaceous Ammonoidea. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

Leave a comment

Your email address will not be published. Required fields are marked *