Fish fin is part of WikiProject Organismal Biomechanics, an attempt at creating a standardized, informative, comprehensive and easy-to-use resource covering organismal biomechanics. If you would like to participate, you can choose to edit this article, or visit the project page for more information.
"Unlike those of vertebrates, however, these are composed of a thickened basement membrane extending from the epidermis"
This distinction would be more useful if someone could explain how they are unlike ray fins in fish, whose composition is not described either here or on the fin ray section. The latter gives some general traits of rays and spines, but no technical information, followed by a description of Lepidotrichia. -- Shimmin Beg (talk) 10:37, 14 February 2013 (UTC)
Have you confused this article with another one? I can't find the sentence you quoted in the article on Fish fin, though it does occur in Chaetognatha. However those are not fish, so it is not the responsibility of this article to clarify the matter.. --Epipelagic (talk) 11:20, 14 February 2013 (UTC)
Gah. Sorry, yes, this was for Chaetognatha and I'll repost there. That being said, it would still be interesting to have some more detail here on the origin (as in, anatomical) and composition of spines and rays in fish fins; the Lepidotrichia section is a good start. -- Shimmin Beg (talk) 10:01, 17 February 2013 (UTC)
It is said that the back legs of ungulates transformed into the tail of a whale. This is not true for whales, although it is true for seals where the back flippers consist of the hind legs. Some whales still have tiny leg bones in the middle of their bodies, not in their tails. The tail of a whale comes from the tail of the ungulate.Tallewang (talk) 18:57, 24 November 2013 (UTC)
Good catch. I've fixed it, and made a few other alterations. HCA (talk) 14:37, 25 November 2013 (UTC)