| 词条 | Brevicoceratidae |
| 释义 |
| fossil_range = {{fossil range|Ludlow|Devonian}} | image = | taxon = Brevicoceratidae | authority = Flower, 1941 }} 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. References1. ^{{cite journal |last1=Flower |first1=Rousseau H. |last2=Kummel |first2=Bernhard |year=1950 |title=Flower & Kümmel; a Classification of the Nautiloidea |journal=Journal of Paleontology |volume=24 |issue=5 |pages=604–616 |jstor=1299547 |ref=harv}} {{Taxonbar|from=Q4962558}}2. ^1 2 3 4 {{cite book |last=Sweet |first=W. C. |year=1964 |chapter=Nautiloidea-Oncocerida |series=Treatise on Invertebrate Paleontology |volume=K |title=Nautiloidea |publisher=Geological Society of America and University of Kansas Press |ref=harv}} 4 : Prehistoric nautiloid families|Silurian first appearances|Late Devonian animals|Late Devonian extinctions |
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