Spyroceratidae
Family of nautiloidea
title: "Spyroceratidae" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["orthoceratoidea", "prehistoric-cephalopod-families", "paleozoic-cephalopods", "carboniferous-cephalopods", "devonian-cephalopods", "permian-cephalopods", "silurian-cephalopods", "silurian-first-appearances", "permian-extinctions"] description: "Family of nautiloidea" topic_path: "general/orthoceratoidea" source: "https://en.wikipedia.org/wiki/Spyroceratidae" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Family of nautiloidea ::
| fossil_range = M Silurian - Permian | image = | taxon = Spyroceratidae | authority = Shimazu & Obata 1935
Spyroceratidae are defined as Pseudorthocerida with uniformly slender siphuncle segments, longer than wide, that contract sharply near either end, in which endosiphuncular deposits first form a compete annulus before fusing ventrally.
References
References
- [[Walter C. Sweet. Sweet, Walter C.]] 1964. Nautiloidea -Orthocerida. Treatise on Invertebrate Paleontology, Part K. Geological Soc. of America and Univ of Kansas press
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