After his lunch on 4 September 1867, the young naturalist Enrico Hillyer Giglioli observed a remarkable baleen whale with two dorsal fins far off the coast of Chile. Due to the unusual fins and an apparent lack of ventral pleats, Giglioli felt the whale was sufficiently distinct to name Amphiptera pacifica and hoped other, luckier naturalists would shortly acquire a specimen*. This never happened. The hypothetical whale is now almost forgotten, aside from being listed as a nomen dubium in databases, but there are still believers. Raynal & Sylvestre (1991) argued that Amphiptera is a valid entity, has been observed on multiple occasions and may be distinct enough to warrant its own ‘family’ (Amphipteridae). While some cetaceans can be surprisingly cryptic, the notion that one of the world’s largest and most unmistakable animals has almost entirely avoided human detection is a tough sell. Additionally, anecdotal evidence – even from experts – is notoriously problematic and cannot be used to describe new species. I’m just not satisfied with leaving Giglioli’s Whale as a nomen dubium, and I suspect the animal he saw was a remarkable representative of a rare, but known, species.
* Which has precedent with Lagenorhynchus cruciger, Cephalorhynchus commersonii & Sousa chinensis. See Dubois & Nemésio (2007) for why hypothetical descriptions are unacceptable today.
The critical information for identifying Giglioli’s whale comes from an illustration included in his 1870, which unfortunately is missing from the Google Books edition. The only copy I can find is from Raynal’s website, and while I can’t vouch for how well it represents the original, all the important details are reasonably visible.
Giglioli’s Whale bears an uncanny resemblance to Caperea marginata – which I refuse to call ‘Pygmy Right Whale’ because that name is the worst – specifically, a stranded 3 meter individual whose dissection was documented at Te Papa’s blog. Caperea was first described in 1846, however knowledge of its external appearance appeared to be quite rudimentary as of Beddard (1901). Giglioli was also only 22 when he observed the whale – having inherited the position of ship’s naturalist after the death of Filippo de Filippi (Croce 2002) – and didn’t appear to have a specialized interest in cetaceans. So not only is it unlikely for Giglioli to have ever heard of Caperea, even if he did the species probably would have been known only from baleen plates and ear bones at the time.
Biological Marginalia 