Tag Archives: Anecdotal Evidence

Weddell’s Long-Necked Seal

From Weddell (1825).

Experts are not immune from making mistakes, even really bizarre ones. Ahem. Take James Weddell for instance, a keen observer of pinnipeds and other marine life (Fogg 1992) who somehow produced the monstrosity above. The intended subject isn’t any old seal, it’s a Weddell Seal (Leptonychotes weddellii)… mostly. The circumstances behind this illustration are vague and contradictory but Fogg (1992) reasoned it was based both on a specimen deposited in the Edinburgh Museum* and Weddell’s memory of wild seals, which may have conflated Weddell and Leopard Seals. It’s probably notable that Weddell referred to his namesake as a “Sea Leopard”.

* Now the National Museum of Scotland.

Weddell (1825) included a brief description of his preserved specimen from one Professor Jamieson who noted the “long and tapering” neck and small head, and argued that Weddell’s Seal had dentition distinct from a Leopard Seal’s. The following year René Primevère Lesson named the species “Otaria weddelli” from Jamieson’s description and Weddell’s illustration but not an actual examination of the specimen, which apparently means Weddell Seals don’t have a proper type specimen (Scheffer 1958). Nobody seems to know why Lesson classified Weddell’s Seal as a Sealion (hence “Otaria“) although I’d suspect it was due to the slender neck. So… what’s up with that mysterious neck?

From Hamilton (1839).

Hamilton (1839) described Weddell’s specimen as having a “proportionally very small” head and a “small, long, and tapering” neck, however the accompanying illustration makes it clear these traits are quite subtle, at least compared to Weddell’s illustration. Hamilton (1839) also took measurements — unfortunately “over the back” — but it’s still interesting that the distance from the snout to the base of the fore-flipper is 1.04 meters compared with a snout-tail length of slightly under 3 meters. It would seem remarkable for a “true” seal to have a head and neck length around one third that of the body, but in fact, it’s totally normal.

Weddell Seal in a more typical pose. From Richardson & Gray (1845).

Despite external appearances, seals and sealions have necks that are proportionally similar in length, although seals typically hold theirs in a deep “S” curve (Rommel & Reynolds 2002). I would highly recommend clicking on this link — the disparity between the external “neck” and the length of cervical vertebrae is truly astounding. As for why seals do this, it’s for “slingshot potential” to capture prey (Rommel & Reynolds 2002), so they’re apparently like snapping turtles, except they hide their necks in blubber rather than a shell. Anyways, Weddell Seals have cervical vertebrae that take up 14% of the vertebrae column (including the tail), and the series is slightly longer than the condylobasal length of the skull (Piérard 1971), so the proportions described by Hamilton are indeed plausible. The posture still seems odd — I can’t find any photographs of a Weddell Seal in such a pose — and I wonder if whoever mounted Weddell’s specimen did so Leopard Seal-style, since that species appears to hold its neck out fairly straight for a “true” seal. It would be interesting to see what the mount actually looks like, but unfortunately, I haven’t been able to track down any photographs.

Since I couldn’t provide a photograph of a Weddell Seal in a weird pose, this walrus will have to do:

From Scheffer (1958).

I can’t help but think of Parson’s long-necked seal and if that was another example of a specimen mounted with an extreme posture whose morphology was exaggerated even more by an illustrator. Curiously, some early workers considered Parson’s and Weddell’s seals to be synonymous (Hamilton 1839), but whatever Parson’s seal was, it probably wasn’t an Antarctic visitor.

References:

Allen, J. (1905) The Mammalia of Southern Patagonia. Reports of the Princeton University Expeditions to Patagonia 3(1) 1–210. Relevant Passage.

Fogg, R. (1992) A History of Antarctic Science. Relevant Passage.

Hamilton, R. (1839) The Natural History of the Amphibious Carnivora. Available. Relevant Passage.

Piérard, J. (1971) Osteology and Myology of the Weddell Seal Leptonychotes weddelli (Lesson, 1826). Available. IN: Burt, W. (editor) Antarctic Pinnipedia.

Richardson, J. & Gray, J. (1845) Zoology of the Voyage of the H.M.S. Erebus and Terror. Available. Relevant Passage. Illustration.

Rommel, S. & Reynolds, J. (2002) Skeletal Anatomy IN: Perrin, W. et al. (eds.) Encyclopedia of Marine Mammals.

Scheffer, V. (1958) Seals, sea lions, and walruses: a review of the Pinnipedia.

Weddell, J. (1825) A Voyage Towards the South Pole. Second Edition Available. Relevant Passage.

Advertisements

The Otter Civet

From the Museum of Comparative Zoology (Harvard)

Otter Civets (Cynogale bennettii) are a poorly known and endangered species of hemigaline viverrid from the Thai-Malay Peninsula, Borneo and Sumatra (Veron et al. 2006). There are also unconfirmed reports from northern Vietnam (“C. lowei“), southern China, northern Thailand and Java (Veron et al. 2006). The mount above appears to be this specimen, and was probably collected in Borneo in 1881 by Henry A. Ward. It certainly shows its age, but it’s no taxidermic aberration — photographs of live specimens show the whiskers and mystacial pads really are that ridiculously hypertrophied.

The illustration above demonstrates more remarkable morphology — the nostrils open dorsally, an even more extreme position than those of seals* and otters (Pocock 1915). Pocock (1915) speculated this feature allows Otter Civets to be ambush predators, picking off unsuspecting birds and small mammals looking for a drink. Nowak (2005) lists birds and small mammals as part of the Otter Civet’s diet and treats Pocock’s speculative behavior as likely, although it still appears to be entirely hypothetical. Any nature documentarians up for filming this potential mammalian mini-crocodile in action? Anyways, Otter Civets also have adaptations for activities below the surface as their nostrils can be closed with flaps, and their ears can be closed as well (Nowak 2005). While some early workers considered Otter Civets to have large orbits (Gregory & Hellman 1939), the eyes appear to be on the small side for a civet, which is unsurprising considering the vast array of whiskers.

* But not Leopard Seals, it would seem.

Viverrids... and prionodontid... on parade!

Top Row: Banded Linsang, Masked Palm Civet
Bottom Row: Binturong, Common Palm Civet, and Otter Civet.

Otter Civet weirdness doesn’t stop at the head. Despite their closest relatives being plantigrade, Otter Civets are fully digitigrade (Gaubert et al. 2005), which is rather unexpected for a semi-aquatic species. The feet are broad with flexible digits and some webbing (Nowak 2005). The tail is curiously short (compare to the civets… and prionodontid… above) and lacks specialized musculature (Nowak 2005). Due to the lack of webbing and underwhelming tail, Nowak (2005) speculated that Otter Civets are slow and unmaneuverable swimmers specialized for capturing cornered prey, which ties in with Pocock’s speculation that the abundant whiskers are an adaptation for discovering hiding prey. Aside from terrestrial species, their diet includes fish, crustaceans and possibly molluscs (Nowak 2005).

Top Row: Otter Civet, Aquatic Genet
Bottom Row: Hemigalus, Chrotogale
All skulls from Gregory & Hellman (1939).

Otter Civets are members of the clade Hemigalinae, along with Hemigalus, Chrotogale, Diplogale and, it was recently argued, Macrogalidia (Wilting & Fickel 2012). The skeletal comparisons above and below also include the Aquatic Genet (Genetta piscivora), a more distant relative that, as the name suggests, is also semi-aquatic. Gregory and Hellman (1939) discussed some minor skeletal traits shared by Otter Civets and Aquatic Genets but found the convergence to be minor. Otter Civet teeth really stand out: the elongate, serrated premolars are specialized for grasping prey while the blunt-cusped, rounded molars are specialized for crushing (Gregory & Hellman 1939; Nowak 2005). Gregory and Hellman (1939) also described an enlarged infra-orbital foramen and enlarged areas for muscle attachment anterior to the orbits which is related to the abundant whiskers and hypertrophied facial musculature, although it’s far less pronounced than what I would have expected. Curiously, there doesn’t seem to be any obvious anatomy relating to the strange position of the nostrils.

Top to bottom: Otter Civet, Aquatic Genet, Hemigalus
Skulls from Gregory and Hellman (1939).

Otter Civets have been kept in captivity and have apparently been observed foraging in water (Vernon et al. 2006), although, full disclosure, I cannot find any specific information on its behavior in water. On land it has been observed doing some surprising things — climbing trees, as well as eating fruit and insects (Nowak 2005; Wilting et al. 2010) — although most observations appear to be fleeting glimpses. Otter Civets are typically photographed nears ponds and streams and are thought to primarily inhabit peat-swamp and primary forests, although they have also been observed in logged and secondary forest (Wilting et al. 2010, Cheyne et al. 2010). However, observations of Otter Civets are becoming increasingly uncommon and it is believed habitat destruction has reduced its population (Veron et al. 2006).

And on a somewhat more upbeat note, here is some of the first footage of Otter Civets in the wild:

References:

Cheyne, S. et al. (2010) First Otter Civet Cynogale bennettii photographed in Sabangau Peat-swamp Forest, Indonesian Borneo. Small Carnivore Conservation 42 25–26. Available

Gaubert, P., et al. (2005) Mosaics of Convergences and Noise in Morphological Phylogenies: What’s in a Viverrid-Like Carnivoran? Systematic Biology 54(6) 865–894. Available

Gregory, W. & Hellman, M. (1939) On the evolution and classification of the civets (Viverridae) and allied fossil and recent Carnivora: A phylogenetic study of the skull and dentition. Proceedings of the American Philosophical Society 81 309–392. Available

Nowak, R. (2005) Walker’s Carnivores of the World.

Pocock, R. (1915) On some of the external characters of Cynogale bennettii Gray. Proceedings of the Zoological Society of London 15(88) 350–360. DOI:10.1080/00222931508693650

Veron, G. et al. (2006) A reassessment of the distribution and taxonomy of the Endangered otter civet Cynogale bennettii (Carnivora: Viverridae) of South-east Asia. Oryx 40(1) 42–49. DOI: http://dx.doi.org/10.1017/S0030605306000068

Wilting, A. & Fickel, J. (2012) Phylogenetic relationship of two threatened endemic viverrids from the Sunda Islands, Hose’s civet and Sulawesi civet. Journal of Zoology 288(3), 184—190. DOI: 10.1111/j.1469-7998.2012.00939.x

Wilting, A. et al. (2010) Diversity of Bornean viverrids and other small carnivores in Deramakot Forest Reserve, Sabah. Malaysia.Small Carnivore Conservation 42 10–13. Available

Giglioli’s Whale

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 crucigerCephalorhynchus commersonii & Sousa chinensisSee 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.

Amphiptera-Caperea

Continue reading