Orthocone cephalopod — Endoceras sp.

Geologic period: Ordovician

Age: Ordovician; exact numeric age of the Smithsonian display shell is not assigned here.

Feeding: Predatory or scavenging ecology is reconstructed from cephalopod biology and associated anatomy, not directly preserved by the shell alone.

Body plan: Orthoconic chambered external shell.

Evidence: Shell geometry and chambers are direct fossil evidence. Soft-body appearance is reconstructed.

Why it matters: Large straight-shelled cephalopods were prominent members of Paleozoic oceans long before coiled ammonites became famous.

Plain Language Identity: A straight-shelled marine cephalopod relative of later nautiloids, ammonoids, squid and octopuses.

What You Are Looking At: A long straight chambered shell rather than the animal's soft body.

Ecosystem: Ordovician marine ecosystem.

Preservation: Mineralized shell fossil.

Open Questions: Do not depict exact coloration or soft anatomy as observed fact.

Source Urls: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list; https://collections.st-andrews.ac.uk/item/endoceras-sp/871306

Enrichment Method: SAGE curated research pass; title and scientific name matched; evidence separated from inference

Scientific name: Endoceras sp.

Evidence / representation: comparative_exact_taxon_visual

comparative_exact_taxon_visual

Oceans Before Dinosaurs: The Rise of Complex Animal Life.

Media license: CC BY-SA 4.0

https://creativecommons.org/licenses/by-sa/4.0