Hamites

Hamites attenuatus, from Wright et al. (1996).

Belongs within: Turrilitaceae.

Hamites is a Cretaceous (Lower Albian to Upper Cenomanian) genus of heteromorph ammonites with the shell growing as subparallel shafts (Wright et al. 1996).

Characters (from Wright et al. 1996): Typically with 3 well-separated, subparallel shafts, but initial spiral or even helical coiling may persist; whorl section circular, depressed or compressed; straight, rectiradiate or oblique ribs typically fine and dense to coarse and distant, but may be obsolescent. Suture florid to rather simple, with wide, bifid L and smaller, trifid or subbifid U. Forms with strong apertural collar and constriction are microconchs; their sutures are not consistently different.

<==Hamites Parkinson 1811 (see below for synonymy)WCH96
    |  i. s.: *Helicoceras’ annulatum Orbigny 1842 [=*Hamitella annulata]WCH96
    |         ‘Helicoceras’ mortoniW77
    |         ‘Helicoceras’ pariense White 1877W77
    |         H. pseudattenuatusP93
    |         H. tenuisW69
    |         H. virgulatus Brongniart in Cuvier & Brongniart 1822 [=*Stomohamites virgulatus]WCH96
    |--H. (Hamites)WCH96
    |    |--*H. (H.) attenuatus Parkinson 1811 [=*Torneutoceras attenuatum]WCH96
    |    `--H. (H.) duplicatusWCH96
    |--H. (Lytohamites Casey 1961)WCH96
    |    `--H. (*L.) similis Casey 1961WCH96
    `--H. (Psilohamites Spath 1941)WCH96
         `--H. (*P.) bouchardianus Orbigny 1842WCH96

Hamites Parkinson 1811 [=Torneutoceras Hyatt 1900; incl. Hamitella Breistroffer 1947, Helicoceras Orbigny 1842 non Koenig 1825, Stomohamites Breistroffer 1940]WCH96

*Type species of generic name indicated

References

[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.

[W77] White, C. A. 1877. Report upon the invertebrate fossils collected in portions of Nevada, Utah, Colorado, New Mexico, and Arizona, by parties of the expeditions of 1871, 1872, 1873, and 1874. U.S. Geographical Surveys West of the One Hundredth Meridian 4 (1): 1–219, pls 1–21.

[W69] Wiedmann, J. 1969. The heteromorphs and ammonoid extinction. Biological Reviews 44: 563–602.

[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).

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