Jangziceras is a fossil nautiloid cephalopod from the Middle Silurian

Silurian

The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...

 of southern China belonging to the Orthocerida

Orthocerida

Orthocerida is an order of extinct nautiloid cephalopods also known as the Michelinocerda that lived from the Early Ordovician possibly to the Late Triassic . A fossil found in the Caucasus suggests they may even have survived until the Early Cretaceous...

 incertae sedis, its familial association undetermined. The type is Jangziceras sichuanense Lai Chai-Geen . Its description falls within the characters of the Orthocerida.

Jangziceras sichuanense was found in the Middle Silurian (Telychian) Lojoping Formation in Szechuan and Kweichow Provinces associated with orthoderids such as Sichuanaceras and Neosichuanoceras

Neosichuanoceras

Neosichuanoceras is an extinct genus of actively mobile carnivorous cephalapod, essentially a Nautiloid, that lived in what would be Asia during the Silurian from 436.0—428.2 mya, existing for approximately .-Taxonomy:...

and oncocerids such as Oocerina

Slender Oncoceratidae

Genera within the Oncoceratidae, a family within the nautiloid order Oncocerida are found in a few basic and distinct forms. among which are those that are slender in proportion. Some like Oocerina are gently curved, almost straight, and with only slight expansion. Others like Dunleithoceras are...

and Guangyuanoceras among other nautiloid genera in reefal

Coral reef

Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...

environments