orthochoaniten.
/ˌɔːθəʊˈkəʊənʌɪt/, U.S. /ˌɔrθoʊˈkoʊəˌnaɪt/ Palaeontology. Now rare.
Usually in plural. A nautiloid cephalopod having a straight, very short septal neck; (also) a member of the obsolete cephalopod suborder Orthochoanites, of which such necks were characteristic.
ΘΚΠ
the world > animals > invertebrates > subkingdom Metazoa > grade Triploblastica or Coelomata > class Cephalopoda > [noun] > order Tetrabranchiata > family Nautilidae > member of > with short septal neck
orthochoanite1919
1898 A. Hyatt in Proc. 47th Meeting Amer. Assoc. Advancem. Sci. 364 The suborders..are as follows:..IV. Orthochoanites. The siphuncles small except in primitive forms and without deposits, or, if present, these are irregular and are gathered around the funnels. No endosiphuncles. The funnels are straight and the siphuncle is apt to be tubular.]
1919 Geol. Soc. Amer. Bull. 30 148 (heading) Relation of the Holochoanites and the Orthochoanites to the Protochoanites and the significance of the Bactritidae.
1944 E. O. Ulrich et al. Ozarkian & Canad. Cephalopods III (Geol. Soc. Amer. Spec. Papers, No. 58) 27 Some of the Canadian nautilicones have lamellar deposits within the camerae... Apparently they are not present in the holochoanites, but they are being found in many orthochoanites and cyrtochoanites of the Paleozoic and the Triassic.
1952 R. C. Moore et al. Invertebr. Fossils ix. 342/1 The Cyrtochoanites have been found to include a very diverse assemblage of which some are closely related to ‘Holochoanites’ and others to ‘Orthochoanites’.
This entry has been updated (OED Third Edition, September 2004; most recently modified version published online March 2022).
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