The Spade-Toothed Whale

It is almost beyond belief that in the 21st Century there was a whale so obscure it was known only from three partial skulls. But no more, the Spade-Toothed Whale (Mesoplodon traversii) has finally turned up in the flesh:

For such a reticent species, the Spade-Toothed Whale has a surprisingly long history. The first known remains consisted of a mandible washed up on the Chatham Islands discovered by a Henry H. Travers (Esq.) in 1872 (van Helden 2002). Hector (1873) classified the mandible as ‘Dolichodon layardii‘, now known as Mesoplodon layardii, the Strap-Toothed Whale. Gray (1874) argued that the Chatham Islands specimen was sufficiently different to warrant status as a distinct species, Dolichodon traversii. While the species are superficially similar in having large teeth with a denticle at the apex, M. layardii specimens consistently have tapering strap-like teeth whereas the M. traversii specimen has shorter, whaler’s spade-shaped teeth with a prominent denticle (van Helden 2002). Hector (1878), without explaining why, stood by his original classification, and for over a century the significance of the jaw from the Chatham Islands went unrecognized.

The first known _Mesoplodon traversii_ remains, from Gray (1873).

_M. layardii_ mandible, from Van Beneden & Gervais (1880).

In 1986, a damaged calvaria (skull sans mandible) was discovered on Robinson Crusoe Island and, despite lacking the typically diagnostic teeth, it was considered distinctive enough to be classified as a new species, Mesoplodon bahamondi (Reyes et al. 1996). Baker (2001) discovered that another calvaria collected in the 1950’s from Whakaari, New Zealand previously thought to be M. ginkgodens was in fact a second specimen of Bahamonde’s Beaked Whale. Analysis of mtDNA revealed that the calvariae were indeed from the same species… as was the mandible from the Chatham Islands (van Helden et al. 2002). Thus a complete picture of the Spade-Toothed Whale’s skull was revealed, but every other aspect of the species’ biology remained a tantalizing blank. It’s a little less blank now.

In December 2010, a female and male calf stranded on Opape Beach, New Zealand and after being initially identified as Mesoplodon grayi, mtDNA revealed they were in fact M. traversii (Thompson et al. 2012). The confusion with M. grayi appears to have resulted from similar mouth-lines, dorsal fin and flipper shape but it is distinctive in having a more prominent melon, and dark rather than white rostrum (Thompson 2012). Thompson (2012) mentions a dark eye patch, white belly, and dark flippers as “notable”, but it appears female M. grayi arguably exhibit these traits as well.

Reyes et al. (1996) estimated that the Robinson Crusoe Island calvaria belonged to a 5.0-5.5 meter whale, and it is curious that the stranded female was close to the midpoint at 5.3 meters long (Thompson et al. 2012). If the Spade-Toothed Whale exceeds 5 meters on average, it would be among the largest mesoplodonts, second only to the Strap-Toothed Whale (MacLeod 2005). Since the two species appear to be similar in size and tooth morphology, it could be possible they occupy a similar niche and avoid competition with spatiotemporal segregation, similar to the North Atlantic ziphiids (MacLeod 2005).

And for even more rampant speculation – has Mesoplodon traversii been seen before? In 1980 and 1983 Bob Pitman observed unknown cetaceans in the East Pacific with extremely long and narrow rostrums, strait gapes, a white mandible contrasting with a dark gray rostrum, and a light patch behind the eyes present in both an apparent mother and calf (Pitman & Lynn 2001). Pitman & Lynn (2001) notably speculated that it may be M. bahamondi, suggesting the ~30 degrees of latitude from Robinson Crusoe Island is not necessarily hugely problematic. Looking at the above photograph of the stranded female, I could see how the described coloration fits, but confusingly the reconstruction in Thompson et al. (2012) has a white area somewhat ahead of the eyes and the beak is entirely dark. Post-mortem color interpretation in whales is notoriously tricky to interpret, and it will probably take photographs of live specimens under clear lighting to document all the subtle aspects of the coloration. While the beak of M. traversii is long, those of female M. grayi are ridiculously so, so this is also problematic. Additionally, the juvenile M. traversii had a “color pattern characteristic of most juvenile mesoplodont beaked whales” (Thompson et al. 2012), apparently meaning it did not have the same coloration as the female. ‘Mesoplodon species B.’ remains an enigma, but I wouldn’t bet against regional M. traversii color variants.

Have I mentioned that this is the marine biological discovery of the century?

References:

Baker, A. (2001) Status, relationships, and distribution of Mesoplodon bowdoini Andrews, 1908. Marine Mammal Science 17, 473-493. DOI: 10.1111/j.1748-7692.2001.tb00999.x

Hector, J. (1873) On the Whales and Dolphins of the New Zealand Seas. Transactions of the New Zealand Institute 5, 154-170. Available.

Hector, J. (1878) Notes on the Whales of the New Zealand Seas. Transactions of the New Zealand Institute 10, 331-343. Available.

MacLeod, C. (2005) Niche Partitioning, Distribution And Competition In North Atlantic Beaked Whales. Doctor of Philosophy Thesis at University of Aberdeen. Available.

Pitman R. & Lynn, M. (2001) Biological observations of an unidentified mesoplodont whale in the eastern tropical Pacific and probable identity: Mesoplodon peruvianus. Marine Mammal Science 17, 648-657. Available.

Reyes, J. C., et al. (1996) Mesoplodon bahamondi sp. n. (Cetacea, Ziphiidae), a new living beaked whale from the Juan Fernández Archipelago, Chile. Boletin del Museo Nacional de Historia Natural, Chile 45, 31-44. Available.

Thompson, K., et al. (2012) The world’s rarest whale. Current Biology 22(1). Available. Supplement.

van Beneden, P.-J. & Gervais, P. (1880) Ostéographie des Cétacés, vivants et fossiles. Available.

van Helden, A., et al. (2002) Resurrection of Mesoplodon traversii (Gray, 1874), senior synonym of M. bahamondi Reyes, van Waerebeek, Cárdenas and Yáñez, 1995 (Cetacea: Ziphiidae). Marine Mammal Science 18(3), 609-621. Available.

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The Cryptic Berardius

_B. arnuxii_ from Wikipedia Commons.

It is sometimes claimed the two species of Giant Beaked Whale (Berardius bairdii, B. arnuxii) are practically identical, and may thus be disjunct populations rather than distinct species (e.g. Reeves et al. 2002, Wikipedia). This seems increasingly unlikely to be true. The species were estimated to have diverged 0.68-5.81 million years ago, which probably makes them younger than the similarly anti-tropical Hyperoodon species (2.37–11.53 mya), but likely older than other cetacean pairs universally considered distinct (Lissodelphis borealis/L. peroniiGlobicephala macrorhynchus/G. melas, etc) (McGowen et al. 2009). Morphologically, the Berardius species differ in flipper size and in the shape of the nasal bones and vomer (Kasuya 2009); the Beaked Whale Identification Guide states that literature describing cranial differences is not yet available, so this list is probably incomplete.

Berardius bairdii is far from uniform itself, as Japanese populations from the Pacific Ocean, Sea of Japan and Sea of Okhotsk reportedly differ morphologically (Kitamura et al. 2012 – citing Kishiro 2007). How, or whether, these purported populations differ genetically has yet to be determined. There is a fourth Japanese population, however, which is unambiguously distinct. In the Sea of Okhotsk (off Hokkaido) slate-gray specimens observed year-round appear to be vanilla B. bairdii, but there are also black individuals present from April to June (Kitamura et al. 2012). These individuals are quite rare, with Kitamura et al. only managing to acquire three in archives. The only specimen with a determined length measured 6.6 meters yet remarkably, it was mature (Kitamura et al. 2012). Comparatively, B. bairdii is believed to first ovulate at 9.8-10.7 m (Kasuya 2009). To put how small 6.6 meters is (for a B. bairdiiin perspective, of the 64 ‘normal’ specimens Kitamura et al. examined, only three were smaller than 6.6 m (5, 4.2, 1.8 m) and they were likely a pre-weaned juvenile (Huang et al. 2009), a newborn (Kasuya 2009) and a fetus, respectively.

Small size on its own is of course not proof of divergence – particularly when only one individual was measured – so that’s where DNA comes in. Nuclear DNA weakly distinguished the black specimens, however mtDNA had high bootstrap values and placed them outside the B. bairdiiB. arnuxii clade. Kitamura et al. suggested that the black Berardius individuals could very well be a cryptic species, although their study was too preliminary to formally describe it. There still remains a lot of genetic and morphological work to sort out just what’s happening with the Berardius variants and maybe some day we’ll see a third species added to the field guides.

A parsimony network of mtDNA CR sequences taken and modified from Kitamura et al. (2012). The circle size indicates abundance, and the small unlabeled circles indicate intermediate or missing haplotypes.

As beaked whales gradually become less mysterious, it seems likely additional cryptic subspecies or even species will be described. This is, of course, a story for another day

References:

Huang, S-L. et al. (2009) Comparable length at weaning in cetaceans. Marine Mammal Science. Available.

Kasuya, T. (2009) Giant Beaked Whales IN: Perrin, W. et al. (eds.) Encyclopedia of Marine Mammals.

Kishiro, T. (2007) Geographical variations in the external body proportions of Baird’s
beaked whales (Berardius bairdii) off Japan. Journal of Cetacean Research and
Management 9, 89–93.

Kitamura, S. et al. (2012) Two genetically distinct stocks in Baird’s beaked whale (Cetacea: Ziphiidae) Marine Mammal Science doi: 10.1111/j.1748-7692.2012.00607.x

McGowen, M. et al. (2009) Divergence date estimation and a comprehensive molecular tree of extant cetaceans. Molecular Phylogenetics and Evolution 53, 891–906. Available.

Reeves, R. et al. (2002) National Audubon Society Guide to Marine Mammals of the World.

Gosse’s Delphinorhynchus

Late in his career, Philip Henry Gosse became convinced that ‘sea-serpents’ reported by proper English eyewitnesses were plesiosaurs. Gosse (1861) argued that a total lack of remains was not necessarily problematic since two cetaceans were also known only from sightings: ‘delphinus rhinoceros‘ and a ‘Delphinorhynchus‘ with “remarkable” white flippers which Gosse happened to observe. The later ‘sea-serpent’ researcher Bernard Heuvelmans (1968) picked up on Gosse’s account and interpreted it as an undescribed species of (probable) beaked whale, a notion which still shows up in cryptozoology books and websites. It’s a shame this purported ‘cryptid’ has never been critically assessed – so far as I can tell – since beaked whales have a long history of being difficult to detect. Gosse’s sighting, however, is also quite problematic and it can probably never be determined just what he saw. That won’t stop me from discussing it, of course.

The Toothless Whale of Havre. From Jardine (1837)

Gosse (1851) observed that one of his mystery cetaceans had a head “exactly” like that of ‘Delphinorhynchus‘, with no furrow between the “forehead” and snout being visible. As for what ‘Delphinorhynchus‘ meant to Gosse, his account describes two species in the now-invalid genus: ‘D. micropterus‘ (“The Toothless Whale of Havre”) and ‘D. rostratus‘. The former is a synonym of the beaked whale Mesoplodon bidens whereas the latter appears to be Gosse’s unique name for the Rough-Toothed Dolphin, Steno bredanensis. These distantly related species have superficially similar heads due to a flat melon and medium-long beak, so Gosse’s cetacean probably had these traits as well. Gosse (1856) was familiar with other ziphiids (‘Hyperoodon bidentatus‘, ‘Diodon sowerbyi‘) but considered them distinct due to their battle teeth; curiously, the latter species is in fact another synonym for M. bidens. Gosse’s understanding of ziphiids was incredibly crude by modern standards, but the description of the head coupled with that of the body (elongated, small dorsal fin set far back) makes it seem likely his mystery cetaceans were beaked whales, and mesoplodonts at that.

‘Delphinorhynchus micropterus’ (top) and ‘Diodon sowerbyi’ from Gosse (1856). Is it me, or has the top one been _Steno_-ized?

Behaviorally, Gosse’s cetaceans could not have been less cryptic. They traveled in a “herd”, “trooping towards the ship” and then stayed with it for around 17 hours and 120 English miles (~190 km). Gosse (1851) made no mention of extended disappearances (due to diving) but did observe the cetaceans “romp and frolic, in the manner of Dolphins”, protrude their heads above the surface, swim on their backs and (as reported by an officer) even breach. The behavior Gosse observed was undoubtedly extreme, but has some precedence in ziphiids: Hyperoodon approaches boats more frequently than other ziphiids (enough so to result in heavy hunting) (Dalebout et al. 2006); large groups of Indopacetus have been noted to be very active at the surface and to approach ships (Anderson et al. 2006); encounter durations in one study of Hawaiian M. densirostris and Ziphius averaged 1.45 hours, with one lasting 8.3 h (McSweeney et al. 2007); another study of M. densirostris found a wide range of reactions to vessels (avoidance, keeping distance, approach) and while surface behavior was usually inconspicuous, tail-slaps, head-raises, porpoising, and even a breach were observed (Ritter and Brederlau 1999). I can’t find any observations of ziphiid diving behavior (apparently) being disrupted for so long, but still, stranger reactions to human presence has been observed – one group of Pseudorca reportedly following a ship from Brazil to the English Channel (Tomilin 1967), for instance.

Gosse’s sighting occurred at 19°1′ N., 45°42′ W. – the middle of the North Atlantic – which is within the ranges of Mesoplodon densirostrisMeuropaeus and ZiphiusHyperoodon ampullatusMbidens and Mmirus are other North Atlantic ziphiids which have been recorded within 10 degrees of latitude of the sighting (MacLeod et al. 2006). Before throwing around the label of ‘cryptid’, it’s critically important to at least review these species and how well they fit Gosse’s descriptions.

The ‘Delphinorhynchus‘ comparison strongly fits with M. bidens and M. europaeus, albeit only if Gosse overlooked the battle teeth in males or observed a group composed only of females and immature individuals. Female M. densirostris may fit, despite the arched jawline, but males are utterly unmistakable. M. mirus is iffy since for a mesoplodont it has a rounded melon and short beak. Ziphius, whose external appearance Gosse was probably unfamiliar with, has a very short beak and melon more pronounced than any mesoplodont, and is thus an unlikely candidate. Gosse (1856) demonstrated he was familiar with Hyperoodon.

Gosse estimated his cetaceans to be about 30 feet (~9.1 meters) in length (“or perhaps not quite so much”), a size only Berardius bairdii regularly exceeds (MacLeod 2005). H. ampullatus may reach 10 m, but is on average much smaller, with a median length of 6.4 m and modes of 6.1-6.2 and 6.4–6.5 m (MacLeod 2005); surprisingly, it really isn’t much longer than the mesoplodonts on average*. Cryptozoologists have a bad habit of interpreting size estimates literally, and considering that this took place at sea and Gosse had no prior experience with ziphiids, I see no reason to dismiss the candidates as a result of this size estimate.

* Ziphius: median 5.5 m, mode 5.4-5.5 m; M. mirus: median 4.76 m, mode 4.8-4.9 m; M. bidens: median 4.5 m, modes 4.5-4.6, 4.8-4.9 m; Meuropaeus: median 4.23 m, mode 4.2-4.3 m; M. densirostris median 4.15 m, modes 3.9-4.0, 4.3-4.4 m (MacLeod 2005).

Gosse described his cetaceans as being black above and white beneath, which doesn’t quite fit any of the candidates. There does seem to be a tendency for at-sea observations to describe species with complex color patterns as “black” (the “Black Dolphin” Cephalorhynchus eutropia being a prominent example), so Gosse’s description isn’t particularly useful, aside from ruling out adult male Ziphius. Gosse also describe the “lips” and extremity of the beak as having a fleshy coloration, and it is worth noting that Ziphius sometimes has pinkish coloration on its head; I’m uncertain if the other species sometimes display this trait, which could be the result of thermoregulation. It is curious that Gosse made no mention of circular or linear scars, but his account implied he was never particularly close to the whales, so they may have been overlooked (along with the battle teeth?).

The trait Gosse felt was most significant were flippers that were white “even on their upper surface”, which contrasted strongly with the dark body. Some M. mirus appear to have partially light flippers, although the surrounding body isn’t exactly dark. I’m curious why Brett Jarrett illustrated some M. densirostris with striking white flippers, perhaps some individuals of that species have been documented with that trait in obscure publications. I’m not exactly convinced white flippers are a trait diagnostic of a new species and not outside the possibilities of individual or population variation. Ritter and Brederlau (1999) noted that some M. densirostris had “coloured” portions of the flippers and other body parts, apparently due to diatoms, so color variation is not necessarily even genetic.

All things considered, I would hesitantly suggest that Gosse observed a large group of Mesoplodon europaeus, possibly largely composed of females and juveniles. The species was discovered a few years before his sighting, but it wasn’t until after Gosse died that it was accepted as a valid species. In typical frustrating fashion, there’s really no way to be sure just what Gosse saw – however there’s also no reason to conclude it’s a new species. Even for beaked whales, a century and a half with no sightings or carcasses is really pushing it.

References:

Anderson, R., et al. (2006) Observations of Longman’s Beaked Whale (Indopacetus pacificus) in the Western Indian Ocean. Aquatic Mammals 32(2), 223-231. Available.

Dalebout, M. et al. (2006) Nuclear and mitochondrial markers reveal distinctiveness of a small population of bottlenose whales (Hyperoodon ampullatus) in the western North Atlantic. Molecular Ecology 15, 3115-3129. Available.

Gosse, P. (1861) The Romance of Natural History. Volume 1. Available.

Gosse, P. (1856) A Manuel of Marine Zoology for the British Isles. Available.

Gosse, P. (1851) A Naturalist’s Sojourn in Jamaica. Available.

Heuvelmans, B. (1968) In the Wake of the Sea-Serpents.

Jardine, W. (1837) The Natural History of the Ordinary Cetacea or WhalesAvailable.

MacLeod, C., et al. (2006) Known and inferred distributions of beaked whale species (Cetacea: Ziphiidae). Journal of Cetacean Research and Management 7(3), 271–286. Available.

MacLeod, C. (2005) Niche Partitioning, Distribution And Competition In North Atlantic Beaked Whales. Doctor of Philosophy thesis for the University of Aberdeen, Aberdeen, UK. Available.

McSweeney, D. et al. (2007) Site fidelity, associations, and movements of Cuvier’s (Ziphius cavirostris) and Blainville’s (Mesoplodon densirostris) Beaked Whales off the Island of Hawai’i. Marine Mammal Science 23(3), 666-687. Available.

Ritter, F. & Brederlau, B. (1999) Behavioural observations of dense beaked whales (Mesoplodon densirostris) off La Gomera, Canary Islands (1995–1997). Aquatic Mammals 25.2, 55-61. Available.

Tomilin, A. (1967) Cetacea. Mammals of the U.S.S.R. and adjacent countries. Volume 9.

Gosse (1851) p. 3-6:

     An occurrence of much more zoological interest, however, the sight of a very rare, if not quite new, Cetacean, under circumstances peculiarly favourable to observation, demands a more protracted notice. Having been familiar with several species of Delphinidæ in former Atlantic voyages, I had taken for granted that I should meet with some in this; and wishing to settle the question whether any of the true Dolphins spout, I had studied the Order a little before sailing; and, in particular, had made careful sketches of the form of the head in all the genera, that I might not depend on that treacherous guide, memory.

November 22d. — Lat. at noon 19° 1′ N., long. 45° 42′ W.; the trade wind blowing a most exhilarating breeze, with fine weather. Between three and four o’clock p.m., a herd of large Cetaceans appeared astern, trooping towards the ship. They soon came up and began to play around us, continuing to romp and frolic, in the manner of Dolphins, all the evening; and even long after nightfall they were still in company, being plainly visible by the light of the moon. During this long time, I had many opportunities of observing them. They frequently protruded their heads from the surface; and then, presently, the huge round back, with a small dorsal far behind, was seen. In going along beside the ship, one would occasionally turn on its back, displaying the white belly, and in this position swim a short distance. The muzzle was lengthened into a snout, but, as well as I could judge from many exposures, it tapered gradually without a furrow, and resembled that of Delphinorhynchus. As nearly as I could estimate from a position aloft, by comparison with the ship, their length was about thirty feet, or perhaps not quite so much. The body was elongated, black above, white beneath; the swimming paws appeared white, even on their upper surface, but surrounded by dark colour on the body; —this is remarkable. The lips and extremity of the muzzle appeared, when projected from the water, of a flesh colour. They usually expired with a rushing sound, the instant the blow-hole was exposed, but did not, as far as I observed, spout. Once, however, I noticed a little cloud of steam sailing away on the wind, from the spot where one had just disappeared; it exactly resembled that appearance which succeeds the spouting of the common Rorqual (which I have seen many times), but as my eye did not catch the animal itself, I cannot positively say that such was its origin on this occasion. The evenings being cool and refreshing after the burning days, and being generally fair, and now lighted by the moon,

“—pura nocturno renidet Luna mari,—” *

we spend them on deck, as the pleasantest hours of the twenty-four. This evening, the wallowing and sporting of the Whales added a new interest; and at nearly eleven o’clock, we left them still in company.
November 23d.— On rising, we were surprised to find the Whales still attending us. I now had an opportunity of seeing the profile of one very distinctly, and of assuring myself that the form of the head was exactly that of the figured Delphinorhynchusno furrow being visible between the forehead and the snout. One of the officers informed me that he had seen one of them breach, or leap clear out of the water. Soon after 8 a.m. they left us, having continued with us nearly seventeen hours, a period of extraordinary length, when we consider that the visits of frolicsome Cetacea to vessels rarely last more than half an hour or an hour. During the whole of this time, the ship had been running before a gallant breeze, and had proceeded nearly 120 English miles.
I have little doubt that the species was that very interesting and rare Cetacean known as the Toothless Whale of Havre, Delphinorhynchus micropterus. The small size of the dorsal, and its backward position, agreed well with the description of that species, and though these were nearly double the length of that celebrated specimen, this incongruity is of little moment, since that was evidently a young one. If this was, indeed, the Havre Whale, the occurrence in associated numbers of a species, hitherto known only by a solitary specimen, possesses an interest which will be readily appreciated by naturalists; if, on the other hand, it was distinct, it is, perhaps, still more interesting, as it proves the existence of a gregarious Cetacean of large size in the Atlantic, which has hitherto escaped the observation of zoologists. The white hue of the flippers, isolated amidst the dark colour of the upper body, would seem to favour the latter conclusion.

I may add here that when we were off the west end of Porto Rico, I observed a shoal of Dolphins playing at a short distance; one of them in leaping fell in a perpendicular position, the tail downward, while the body was thrown into a double curve. I was thus enabled to see that the belly was of a bright rose-colour. Now this is the hue of the under parts of the other Delphinorhynchus (D. rostratus), which is about eight feet in length, and might well be mistaken, in the moment of leaping, for a true Delphinus. The coincidence is a curious one: especially as this species is nearly as rare as the former.

The Rhinoceros Dolphin

In 1820, Quoy and Gaimard described two species of dolphins from sightings, now believed to be the first documented encounters with Hourglass Dolphins (Lagenorhynchus cruciger). In 1826, Hourglass Dolphins were described again (as Delphinus bivittatus‘) from far more detailed sightings by Lesson and Garnot (Jardine 1837). Finally* in 1830, d’Orbigny acquired a specimen and preserved its skull in a museum (True 1889), ending the 10 year run as a… cryptid, of sorts. In contrast, Quoy and Gaimard also described ‘delphinus rhinoceros‘ from a sighting and the species is now regarded as a nomen dubium, having never been observed again despite the striking feature of a supernumerary dorsal fin or horn on its head. It would seem likely that Quoy and Gaimard were mistaken, but what did they actually see?

* To be fair, the taxonomy of Hourglass and other Southern Hemisphere dolphins was confused for a long time after. For instance, Hourglass Dolphins were named from sightings again (as ‘Lagenorhynchus wilsoni‘)… in 1915!

Quoy and Gaimard’s ‘delphinus rhinoceros’. From Jardine (1837)

Michel Raynal documented some possible explanations – Georges Cuvier proposed it may have been an optical illusion and Richard Ellis suggested it may have been a dolphin with a remora stuck on its head. Raynal himself suggested it may have been misobserved somersault behavior (with the first fin being a flipper and the second being a fluke) but dismissed it as unlikely. Markus Bühler pointed out that one dolphin’s deformed jaw curiously resembles the oddly placed fin or horn of the Rhinoceros Dolphin. Supernumerary dorsal fins are apparently a genuine abnormality, judging from photographs of twofinned humpbacks and Snooky the dolphin, however none have turned up a considerable distance from the normal fin, let alone on the head. Raynal and Sylvestre (1991) argued that since Quoy and Gaimard observed multiple individuals exhibiting the morphology, a distinct species (‘Cetodipterus rhinoceros‘†) would be more probable than a pod of disfigured individuals. The authors didn’t appear to consider the possibility that the cause was genetic and that the individuals may have been some freakish inbred clan, the Blue Fugates of the seas, if you will. There is another possibility – that Quoy and Gaimard observed specimens which were neither deformed nor members of an unknown species or population.

† Renamed since Delphinus is now far less inclusive and the cryptid may not have been a dolphin. ‘Oxypterus rhinoceros‘ is another synonym proposed by Lesson (Jardine 1837) however the type species of the genus (Rafinesque’s ‘Oxypterus mongitori‘) was vaguely described with a second dorsal fin (and scales, gill-slits, and an anal fin) being present only in a dubious secondhand illustration.

At some point, Raynal discussed the possibility that the ‘Rhinoceros Dolphin’ may actually be a beaked whale (Eberhart 2002) which made me realize there’s already a species with bizarre fin-like or horn-like projections coming out of its head – male Mesoplodon densirostris. Let’s see how this hypothesis stacks up with Quoy and Gaimard’s written account:

Dans le mois d’octobre 1819, en allant des îles Sandwich à la Nouvelle-Galles du Sud, nous vîmes, par 5° 28′ de latitude N.,

The encounter occurred in October 1819, somewhere between Hawai’i and New South Wales at 5° 28′ North. Quoy and Gaimard were probably unaware of Mesoplodon densirostris since it was described in 1817, the year they set sail. The holotype was a partial rostrum, so even if Quoy and Gaimard somehow learned of the whale, they would have been unaware of its external appearance. Mesoplodon densirostris is believed to inhabit tropical through warm temperate waters across the world (MacLeod et al 2006), so the vague locality is not an issue.

beaucoup de dauphins (planche 11figure 1), exécutant en troupes,

“Many” dolphins in “troops” were observed. One study of 19 encounters with M. densirostris off Hawai’i found that groups are usually small (median = 3, mean = 3.53) with a maximum of 9 individuals (McSweeney et al. 2007). This is a potential problem for the M. densirostris hypothesis and it’s a real shame that Quoy and Gaimard didn’t give a rough idea of the total number – would 9 individuals be “beaucoup” for 19th Century Frenchmen? It is curious that the illustration shows only a single individual, which, coupled with the ambiguous count, makes me wonder if only one individual investigated the ship while the others remained some distance away. It’s worth noting that groups of M. densirostris were not observed to have more than two males (McSweeney et al. 2007).

autour du vaisseau, leurs rapides évolutions:

This appears to state that the animals were changing direction around the ship. This is potentially problematic for M. densirostris since it has two projections and not one. Since the illustration shows an animal from the side, this makes me wonder if it was circling the ship, and maintaining the illusion of a single horn or fin.

tout le monde à bord fut surpris, comme nous, de leur voir sur le front une corne ou nageoire recourbée en arrière, de même que celle du dos.

To everyone’s surprise, there was a horn or curved dorsal fin on their foreheads, in addition to a dorsal fin on their backs. Raynal & Sylvestre (1991) translate “sur le front” as “on their snouts” and argue that the illustration demonstrates the supernumerary dorsal fin was actually behind the head. The illustration of course doesn’t show any demarcation indicating where the head is located and shows a cetacean with fairly dubious proportions, probably warped so both fins could be visible at once. I don’t think the illustration is useless, just that Quoy and Gaimard’s statements should be given precedence.

Le volume de l’animal étoit à-peu-près double de celui du marsouin ordinaire,

The animals had a volume twice that of a “common porpoise”, presumably the Harbor Porpoise (Phocoena phocoena). Raynal & Sylvestre (1991) interpret “volume” as “length” and suggest Quoy and Gaimard estimated ‘delphinus rhinoceros’ to be ~3 meters in length. However, Quoy and Gaimard (1824) used “longueur” for length and “volume” for volume in their book, so they apparently (and improbably) estimated ‘delphinus rhinoceros’ to weight around 100-120 kg. This would make it ~2 meters in length if shaped like a porpoise. It’s worth noting that estimating size at sea is notoriously difficult, making Quoy and Gaimard’s already ambiguous estimate fairly useless. M. densirostris has a mean length of 4.15 meters (MacLeod 2005), by the way.

et le dessus de son corps , jusqu’à la dorsale, étoit tacheté de noir et de blanc.

The animals were spotted black and white. The illustration clarifies that these are irregular white spots on a dark background. This of course looks strongly reminiscent of the coloration of M. densirostris, the white blotches being scars from Cookiecutter Sharks (which Quoy and Gaimard described).

Nous nous attachâmes à observer ces dauphins pendant tout le temps qu’ils nous accompagnèrent : mais quoiqu’ils- passassent souvent à toucher la proue de notre corvette,

The group accompanied the boat, often approaching close enough to touch the bow of the ship.

ayant le haut du corps hors de l’eau, leur tête y étoit tellement enfoncée, que ni M. Arago, ni nous, ne pûmes distinguer si leur museau étoit court ou alongé: leur allure même ne put rien nous indiquer à cet égard; car ils ne s’élançoient point au-dessus des eaux comme les autres espèces.

Only the top part of the animals were held out of water. The head was depressed and it was not possible to determine if the snout was short or elongated. The depressed head is certainly consistent with the flat melon of mesoplodonts. I cannot find a translation for the word “élançoient”… I hope it’s not important.

D’après leur conformation toute particulière, nous les avons nommés dauphins rhinocéros [ delphinus rhinoceros ].

They shall be called… Rhinoceros Dolphins!

The notion that Rhinoceros Dolphins are a species which hasn’t been seen in 190 years is… a bit much, especially considering their unmistakable profile and lack of fear of vessels. The only supporting evidence for this cryptid are dolphin figurines Raynal has documented – the purported “dorsal fins” on the head look like a normal continuation of the melon to me. Mesoplodon densirostris isn’t a perfect candidate, but the similarities are suspicious and we already know Quoy and Gaimard aren’t perfect observers. In order for the beaked whales to work as a candidate, Quoy and Gaimard would have to observe a large group where one or two males investigated the ship by circling it, remaining in lateral view, creating the illusion of having one horn or head-fin and leading the authors to believe the others had them too.

There are still some big surprises out there, and recently there has been a major beaked whale discovery in the tropical Pacific – the resurrection of Mesoplodon (ginkgodens?) hotaula.

References:

Eberhart, G. M. (2002) Mysterious Creatures: A Guide to Cryptozoology.

Jardine, W. (1837) The Natural History of the Ordinary Cetacea or Whales. Available.

MacLeod, C. D. et al. (2006) Known and inferred distributions of beaked whale species (Cetacea: Ziphiidae). Journal of Cetacean Research and Management 7(3), 271–286. Available.

MacLeod, C. D. (2005) Niche Partitioning, Distribution And Competition In North Atlantic Beaked Whales. Thesis for Doctor of Philosophy at the University of Aberdeen, Aberdeen, UK. Available.

McSweeney, D. J. et al. (2007) Site fidelity, associations and movements of Cuvier’s (Ziphius cavirostris) and Blainville’s (Mesoplodon densirostris) beaked whales off the island of Hawai’i. Marine Mammal Science 23(3), 666-687. Available.

Raynal, M. & Sylvestre, J-P. (1991) Cetaceans with two dorsal fins. Aquatic Mammals 17.1, 31-36. Available.

Quoy and Gaimard. (1824). Voyage autour du monde.. l’Oranie et la Physicienne… ZoologieAvailable.

True, F. W. (1889) A Review of the Family Delphinidæ. Bulletin of the United States National Museum 36. Available.

Tasmacetus on Film

I’m late to the story, but the first-ever video of the beaked whale Tasmacetus shepherdi is beyond irresistible.

The 2006 paper referenced in the video is undoubtedly Pitman et al. (2006), which provided the first accurate description of the whale’s coloration. It is mind-boggling that the external appearance of a whale could be uncertain until so recently. Indopacetus, the external appearance of which wasn’t nailed down until 2003, looks very similar to Tasmacetus but clearly isn’t the species in the video. The pale melon, long dark beak and white shoulder patch considered diagnostic for vessel encounters with Tasmacetus (Pitman et al. 2006) are clearly visible and I think I even caught a glimpse of the very distinctive cape. The 4 (or 5?) whales in the video are consistent with other observations of group size for the species (3-6), although the previous sample size was only four (Pitman et al. 2006). One interesting detail from the video is that it answers Pitman et al. (2006)’s query as to whether or not the blow of this species would be visible from a vessel, as it shows that the blows are perhaps as prominent as those from Berardius and Hyperoodon. There are undoubtedly other things that the video shows that I haven’t picked up on, so I’ll try and get the jump on the paper when it eventually surfaces.

_Tasmacetus_ is a bit toothier than your bog standard beaked whale. From Mead and Payne (1975).

The coloration of Tasmacetus is curiously dolphin-like as it exhibits a dark cape, flipper stripe and no differences between sexes and age groups (Pitman et al. 2006). Another curiously dolphin-like trait is that in addition to the battle teeth, both jaws have full sets of functional teeth (Pitman et al. 2006). This is not necessarily a radical departure from other beaked whales. The fossil ziphiids Messapicetus and Ziphirostrum apparently had functional teeth in both jaws (Lambert 2005) despite being relatives of the conventionally toothed Ziphius (Bianucci et al. 2007). Mesoplodon grayi has apparently functional teeth in its upper jaw and non-battle teeth are sometimes present in the lower jaw as well (Robson 1975). It’s certainly puzzling what retentions and/or reversals could have led to such an odd arrangement of toothy species, although since beaked whale systematics show no sign of getting resolved any time soon perhaps it’s best not to think about this at the moment. Ziphiids certainly don’t seem to be close relatives of dolphins so it seems likely the dolphin-y traits of Tasmacetus are convergences rather than retentions. As for why they’re pretending to be giant dolphins, who knows.

I also can't resist bizarre reconstructions. This one is fine up until the flippers and then... yikes. From Mead and Payne (1975).

References:

Bianucci, Giovanni et al. (2007) A high diversity in fossil beaked whales (Mammalia, Odontoceti, Ziphiidae) recovered by trawling from the sea floor off South Africa. Geodiversitas 29(4), 561-618. Available.

Lambert, O.. 2005. Systematics and phylogeny of the fossil beaked whales Ziphirostrum du Bus, 1868 and Choneziphius Duvernoy, 1851 (Mammalia, Cetacea, Odontoceti), from the Neogene of Antwerp (North of Belgium). Geodiversitas 27(3), 443-497. Available.

Mead, J. G. (2008) Shepherd’s Beaked Whale (Tasmacetus shepherdi). IN: Perrin, W. F., Würsig, B., & Thewissen, J. G. M. Encyclopedia of Marine Mammals. Academic Press.

Mead, J. G. & Payne R. S. (1975) A specimen of the Tasman Beaked Whale, Tasmacetus shepherdi, from Argentina. Journal of Mammalogy 56(1), 213-218.

Pitman, R. L. et al. (2006) Shepherd’s Beaked Whale (Tasmacetus shepherdi): Information on appearance and biology based on strandings and at-sea observations. Marine Mammal Science 22(3), 744-755. Available.

Robson, F. D. (1975) On vestigial and normal teeth in the Scamper-Down Beaked Whale, Mesoplodon grayi. Tuatara 21(3), 105-107. Available.