Nautiloid
Also known as Nautiloidea
Nautiloids are a group of cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living Nautilus and Allonautilus. Fossil nautiloids are diverse and species rich, with over 2,500 recorded species. They flourished during the early Paleozoic era, when they constituted the main predatory animals. Early in their evolution, nautiloids developed an extraordinary diversity of shell shapes, including coiled morphologies and giant straight-shelled forms (orthocones). No orthoconic and only a handful of coiled species, the nautiluses, survive to the present day.
Species
nautilus
Subclass
- PhylumMollusca
- ClassCephalopoda
Habitatmarine
Les Nautiloidea, ou communément Nautiloïdes, est une sous-classe de mollusques céphalopodes à coquille univalve. Le siphon reliant les logettes de leur coquille est axial, alors qu'il est en position externe (ventrale), le long de la paroi, chez les ammonites. Les Nautiloïdes sont d'excellents marqueurs stratigraphiques. Liste des ordres Selon BioLib (27 janvier 2018)[2] : ordre Discosorida † ordre Ellesmerocerida † ordre Nautilida Blainville, 1825 -- Nautiles ordre Oncocerida Flower, 1950 † ordre Tarphycerida Flower, 1950 † genre Pleuronoceras † Notes et références ↑ Integrated Taxonomic Information System (ITIS), www.itis.gov, CC0 https://doi.org/10.5066/F7KH0KBK, consulté le 27 janvier 2018 ↑ BioLib, consulté le 27 janvier 2018
via
~26 min read
Article
15 sectionsContents
- Taxonomic relationships
- Shell
- Modern nautiloids
- Fossil record
- Evolutionary history
- Timeline of orders
- Classification
- Older classification systems
- Early cladistic efforts
- Recent revisions
- Gallery
- See also
- References
- Further reading
- External links
Nautiloids are a group of cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living Nautilus and Allonautilus. Fossil nautiloids are diverse and species rich, with over 2,500 recorded species. They flourished during the early Paleozoic era, when they constituted the main predatory animals. Early in their evolution, nautiloids developed an extraordinary diversity of shell shapes, including coiled morphologies and giant straight-shelled forms (orthocones). No orthoconic and only a handful of coiled species, the nautiluses, survive to the present day.
In a broad sense, "nautiloid" refers to a major cephalopod subclass or collection of subclasses ('Nautiloidea sensu lato). Nautiloids are typically considered one of three main groups of cephalopods, along with the extinct ammonoids (ammonites) and living coleoids (such as squid, octopus, and kin). While ammonoids and coleoids are monophyletic clades with exclusive ancestor-descendant relationships, this is not the case for nautiloids. Instead, nautiloids are a paraphyletic grade of various early-diverging cephalopod lineages, including the ancestors of ammonoids and coleoids. Some authors prefer a narrower definition of Nautiloidea (Nautiloidea sensu stricto'''), as a singular subclass including only those cephalopods which are closer to living nautiluses than they are to either ammonoids or coleoids.