Brevicoceratidae
The Brevicoceratidae is a family of oncocerids that contains genera characterized by exogastric (or rarely endogastric) gyrocones, brevicones, and torticones.[1][2] that tend to develop vestigial actinosiphonate deposits and subtriangular transverse sections. The Brevicoceratidae are derived from Oonoceras (Oncoceratidae) and range from the mid-Silurian to the Upper Devonian.[2] Brevicoceratidae is named for the Middle Devonian genus, Brevicoceras, from North America.[2] All told there are some 17 named genera. The family begins with Oxygonioceras in the Middle Silurian,[2] sole recognized representative of that time, and reaches its greatest diversity with 12 genera in the Middle Devonian.[2] The Brevicoceratidae are reduced to four genera in the Upper Devonian, when they become extinct. References
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