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Semionotiformes

Extinct order of fishes

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Semionotiformes is an order of ray-finned fish known from the Middle Triassic (Anisian) to the Late Cretaceous (Maastrichtian). It is the sister group to Lepisosteiformes, the order containing fish such as Lepidotes and Gars. The group includes both freshwater (Semionotidae) and marine (Callipurbeckiidae, Macrosemiidae) adapted forms. Many members of the family Macrosemiidae, had elongated dorsal fins, often associated with an adjacent area of skin which was free of scales. These fins were likely undulated for use in precision swimming. The body morphology of macrosemiids suggests that they were slow swimmers who were capable of maneuvering around complex topography, such as reef environments.

01Classification

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This article is adapted from the Wikipedia article Semionotiformes, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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