I think it could be a genetic abnormality, and not a separate species.
www.marinespecies.org...
Not documented.
Umm... looks like it's just that one. That's all I can find
Online "artists impressions" show this dolphin to have a large "central" dorsal fin with a smaller one behind. But according to the books I've checked and he description of French naturalists Jean Quoy and Joseph Gaimard suggest the extra dorsal fin was actually smaller and towards the front which I think makes more sense vis-a-vis the name as well. (Sidenote: some "freak" common dolphins have been observed with a secondary dorsal fin towards their rear as per those pictures so I think the "artists" might just be getting very confused between the two different cryptid puzzles).
Quoy and Gaimard were off New South Wales in 1819 when they made their sighting of a pod of such dolphins which they described it's other features thus:
"The volume of the animal was about double that of the ordinary porpoise, and the the top of its body, as far as the dorsal fin, was spotted black and white."
They named it Delphinus rhinoceros. Other reports from the Atlantic and Mediterranean have also been made of this dolphin.
moonlightinvestigation.blogspot.com...
These guys are spotted though:
en.wikipedia.org...
en.wikipedia.org...
www.rockisland.com... (Atlantic Spotted Dolphin)
[edit on 8/3/2009 by ravenshadow13]
