Definition of Orthocones. Meaning of Orthocones. Synonyms of Orthocones

- bactritids. Orthocones existed from the Late Cambrian to the Late Tri****ic, but they were most common in the early Paleozoic. Revivals of the orthocone design...
- shapes, including coiled morphologies and giant straight-s****ed forms (orthocones). No orthoconic and only a handful of coiled species, the nautiluses,...
- over 470 million years ago. The Bactritida, a Devonian–Tri****ic group of orthocones, are widely held to be paraphyletic without the coleoids and ammonoids...
- Antarctica. These are straight s**** that closely resemble those of the orthocones, although they are thought to have been internal akin to those of certain...
- Orthoceras referred to all nautiloids with a straight-s****, called an "orthocone" (Fenton & Fenton 1958:40). But later research on their internal structures...
- Baculites, which has a nearly straight s**** convergent with the older orthocone nautiloids. Still other species' s**** are coiled helically (in two dimensions)...
- gap of nearly 50 million years occurs between Bactroceras and the next orthocones with a spherical apex and ventral siphuncle. Bactritids, especially the...
- dominant marine arthropods (e.g. eurypterids) and cephalopod molluscs (e.g. orthocones), producing some of the first and most infamous vertebrate apex predators...
- diameter and thickness of a calciosiphonate connecting ring and shape of orthocone siphuncles. Orthocerida may thus be a polyphyletic group, having arisen...
- deep-water settings. Nanglu et al. (2023) report the discovery of an orthocone cephalopod phragmocone from the Ordovician Fezouata Formation (Morocco)...