Definition of ray-finned

: having fins supported by bony or horny rays (see ray entry 2 sense 5a(1)) : acanthopterygian The vast majority of ray-finned fish species are contained in the Teleostei, a clade noted for its diversity of behavior, functional morphology, and ecology in aquatic habitats throughout the world.— George V. Lauder, Quarterly Review of Biology, March 1999 Morays belong to a group called ray-finned fishes that includes a vast majority of fish species, like tuna, goldfish, salmon and trout.— Carl Zimmer, New York Times, 11 Sept. 2007 — compare lobe-finned

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Other Words from ray-finned

ray-fin noun, plural ray-fins
All the fossils belonging to the ancestral group that gave rise to ray-fins some 300 million years ago came from freshwater deposits. — Colin Barras, New Scientist, 11 Feb. 2012

First Known Use of ray-finned

1933, in the meaning defined above

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The first known use of ray-finned was in 1933

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Dictionary Entries Near ray-finned

ray filter


ray flower

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Cite this Entry

“Ray-finned.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ray-finned. Accessed 18 Jan. 2022.

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