Sotalia tëuszii

Sotalia tëuszii is a species of dolphin described by Willy Kükenthal in a German zoological yearbook in 1892. The specimen's skull was collected by a Mr. Eduard Tëusz, but his description of the animal's life appearance is what really caught my eye. The dolphin was 8-9 feet long and captured off the coast of Cameroon, west Africa. It's described as having two tube-like nasal openings on its head, like "that of the hippopotamus with its ears pushed high upon its head". No dolphin is known to have two seperate nasal openings, let alone in a chimney stack configuration.

It really reminds me of the cetaceans drawn on 16th century maps, whose "spouts" were very much spouts.

 

 

The dolphin's skin is also described as thick like that of a manatee. And even more interesting, "Mr. Tëusz found its stomach filled with vegetables, and it was leaves and mangrove fruits, rather than grass, that formed the contents of the stomach".

 

A HERBIVOROUS DOLPHIN.

If this dolphin really exists, it would be the only known herbivorous cetacean. F. E. Beddard's 1900 A Book of Whales suggests that Tëusz's dolphin probably has unique plant-munching teeth distinct from fish-eating dolphins. Author Willy Kükenthal goes on to describe the skull collected by Mr. Tëusz. He assigns it to the genus Sotalia, despite all known Sotalia dolphins living in South America, not west Africa.

 

Around this time, a LOT of Sotalia dolphins were being described. A Book of Whales lists 10 species. Today, we only recognize 2, the Tucuxi and the Guiana Dolphin. (S. gadamu, Elliot's Dolphin, is also currently on my “to-draw” list. That species would persist in books until at least the 1970s.)

 

 

I remember @/PetrichorCrown on Twitter suggesting this S. tëuszii might be a misidentified African Manatee, which seemed highly likely considering the herbivorous diet and skin explicitly described as "like a manatee". However, it turns out the skull belongs to a very real dolphin. The skull belongs to what is now known as Sousa teuszii, the Atlantic Humpback Dolphin. Sotalia tëuszii is considered a synonym for Sousa teuszii, but as far as I know, nobody has any explanation for the bizarre features originally described by its discoverer and namesake, Eduard Tëusz.

 ~~~~~~~~~~~~~~~~~~~~~~~~~~

Sources:

Zoologische Jahrbücher Abtheilung für Systematik, Geographie und Biologie Der Thiere Herausgegeben Von Prof. D. J. Spengel, 1892, pages 442-446
https://www.biodiversitylibrary.org/item/38749#page/452/mode/1up

A Book of Whales, F. E. Beddard, 1900, page 268 and pages 271-272
https://www.biodiversitylibrary.org/page/1398420#page/323/mode/1up

 

Nomenclature of the dolphins, porpoises, and small whales: a review and guide to the early taxonomic literature, Thomas A. Jefferson, 2021
https://spo.nmfs.noaa.gov/sites/default/files/PP21.pdf