Editing Endocerida (section)

{{short description|Fossil order of cephalopods}}
{{Automatic taxobox
| fossil_range = {{fossil range|Floian|Hirnantian|latest=early Silurian|ref=<ref name=Kroger2009/><ref name="Barskov2008"/>}}
| image = Cameroceras_trentonese.jpg
| image_caption = The massive endocerid ''[[Cameroceras]]'' (middle) alongside other nautiloids
| taxon = Endocerida
| authority = Teichert, 1933
| subdivision_ranks = Families
| subdivision = † [[Cyrtendoceratidae]]<br>
† [[Endoceratidae]]<br>
† [[Proterocameroceratidae]]<br>
† [[Yorkoceratidae]]
}}

'''Endocerida''', from [[Ancient Greek]] ἔνδον (''éndon''), meaning "inside", and κέρας (''kéras''), meaning "horn", is an extinct [[Nautiloidea|nautiloid]] order, a group of [[cephalopod]]s from the Lower Paleozoic with cone-like deposits in their [[siphuncle]]. Endocerida was a diverse group of [[cephalopod]]s that lived from the Early [[Ordovician]] possibly to the Late [[Silurian]]. Their shells were variable in form. Some were straight ([[orthoconic]]), others curved (cyrtoconic); some were long (longiconic), others short (breviconic). Some long-shelled forms like ''[[Endoceras]]'' attained shell lengths close to {{convert|6|m|ft}}. The related ''[[Cameroceras]]'' is anecdotally reported to have reached lengths approaching {{convert|9|m|ft}}, but these claims are problematic. The overwhelming majority of endocerids and nautiloids in general are much smaller, usually less than a meter long when fully grown.