The name of this blog will live on as a tumblr consisting of all sorts of odds and ends and kinda-copyrighted things (hooray for havens), but it is time to get less serious and dust off The Lord Geekington. I need a fresh start so this one will be different, it’s got a The.
On 10 December 2__3, the UAC bases Phobos and Deimos were overrun by unidentified combatants. Footage of the events were captured by a Spacemarine operating the T.A.G.G.A.R.T. combat system, however, due to the several metric tonnes of weapons and munitions, there was only room for a 256 color 480×360 Steadicam. Despite the limited resolution, the bright, colorful graphics captured numerous remarkable morphological and behavioral traits of the “alien” or “demon” invaders. Type specimens were never collected from the now-abandoned bases, and as such, this footage, along with a few cultural depictions, remains the only evidence of the invaders.
55 morphological traits were recorded and included head/torso fusion, horn morphology, exposed brains, paired posterior sphincters, flight et cetera. There were 11 additional traits detailing behavior, 39 relating to sounds and 44 detailing toughness, size, reaction time and estimated mass. In all, there were 149 traits (32 multi-state) and 11 apparent taxa. The program MrBayes was used to analyze the Standard data and was run for 1,000,000 generation, finishing with an average stdev of split freq of 0.002921 and a TL PSRF of 1.000. The most parsimonious tree is as follows:
Perhaps the most surprising clade (bootstrap value of 100) is that consisting of the seemingly-disparate “Lost Soul”, “Cacodemon” and “Spiderdemon”. The latter two share the highly unusual trait of head/body fusion, whereas the “Soul” lacks any evidence of a body at all; its presence in the group could be the result of long-branch attraction. It is also notable that the “Spiderdemon” has extensive cybernetic modifications, so knowledge of its original state (if any) could significantly change its placement. One clade of horned, digitigrade “demons” (“Cyberdemon”, “Baron of Hell”, “Demon” and “Spectre”) receiving surprisingly low support (bootstrap value of 63) for unknown reasons. Also curious is that the most basal “demon”, the “Imp” is also the most humanoid, raising the question of what sort of relationship these aliens have with Homo sapiens.
A second incursion event occurred on 30 September 2––4, this time on various Earth locations. Steadicam footage was of similar quality to the first event and managed to record 7 additional taxa. The number of traits was expanded to 201, with 33 being multi-state. MrBayes was once again used to analyze the Standard data and run for 1,000,000 generations, ending with an average stdev of split freq of 0.006850 and TL PSRF of 1.000.
Interestingly, the position of the “Imps” is now closer to the horned, digitigrade “demons”, with two humanoid taxa (“Arch-Vile”, “Mancubus”) now occupying and unresolved position between the “former” humans and other demons. Interestingly, one taxa (“Revenant”) with some human-like traits (especially clothing and weapon use) is not a member of this polytomy. Also interesting is that the position of the “Lost Soul” is essentially unchanged and in fact more highly resolved with the additional taxa. The sister taxa of the “Cacodemon”, the “Pain Elemental”, is highly similar in being a volant, cyclopian entity with head/body fusion, although has “Spiderdemon”-like arms, “Cyberdemon”-like horns and bizarrely spits out “Lost Souls”; horizontal gene transfer seems like a likely explanation for this hodgepodge.
There are reports of a third incursion on a Mars base, however the high resolution footage is unfortunately far too dark to be of any use. There are projections that in a few years a fourth incursion will occur, so I advise future researchers to grab their double-barreled shotguns, strap a flashlight to the top, and bag some type specimens.
…
I’m not making these numbers up: here’s the data sheet. I can’t upload .nex files for some reason, but they can be easily recreated using that data. I should clarify that this isn’t phylogenetics — the study of evolutionary relationships — however, it is still cladistics — grouping based on shared, derived characteristics. I suppose ideas can evolve as designers swap and redesign ideas, and it does seem that cladistics can group them reasonably well. Of course, there could very well be some severe methodological flaws that I overlooked or a better method (phenetics?) but, eh, it’s April 1st.
This post owes a lot to the Doom Wiki, Spriters Resource, and of course the folks at id Software who made the games.
Harbor Seal at Roger Williams Park Zoo
I’d bet that most casual observers of Harbor Seals (Phoca vitulina) are under the impression that the little pinnipeds are almost neckless. Of course, it’s not immediately obvious what the skeletal proportions are underneath that blubber, but judging by the forelimb origin, it would seem the neck is less than half the length of the head. Harbor Seals are hiding more neck than what they let on, as their cervical vertebrae are actually similar in length to the skull:
Harbor Seal skeleton from Museum of Comparative Zoology
Clearly the live animal above was not holding its neck in the same posture as this skeleton, and (not having X-Ray specs) I’d assume it was similar to the deep “S” curve in this Harp Seal. As for why seals would shorten their apparent necks so dramatically, King (1983) suggested phocids (“true” seals) require a spindle-like shape when swimming since their propulsion comes from oscillating the posterior end of their body. But why bother having a neck at all? A strongly retracted neck gives seals “slingshot potential” to capture prey (Rommel & Reynolds 2002), as alarmingly demonstrated by this Leopard Seal. It’s surprisingly difficult to find photographs of Harbor Seals showing off their full neck — presumably they only do it rarely and briefly — but blogger Kitty Kono has an amazing snapshot:
From Kitty Kono’s blog Back in the U.S.A. Used with permission.
I of course covered all this in my Weddell’s Long-Necked Seal article, but now, I’ll take things further by determining just how long seal necks are. The tails and sacral vertebrae varied much more than what I expected (plus one source often lumped the two), so rather than measure necks relative to the length of the entire spine, I did so relative to only the thoracic and lumbar vertebrae (T–L from here on). And yes, there is going to be an appendix to this blog post.
Black = Skull (gray for no data); Red = Cervical, light blue background equal to shortest neck, pink equal to longest neck; Blue = Thoracic; Green = Lumbar; Yellow = Sacral; Orange = Caudal.
Species are (top to bottom): Dog, Bearded Seal (Erignathus), Weddell Seal (Leptonychotes), Southern Elephant Seal (Mirounga leonina), Leopard Seal (Hydrurga), Hooded Seal (Cystophora), Harbor Seal (Phoca vitulina), Ringed Seal (Pusa hispida), Harp Seal (Pagophilus).
Phocid necks range from 21% T–L in Bearded Seals to 35% T–L in Harp Seals*, which falls short of dogs with necks 40.5% of their T–L. Weddell seals were initially described as “long-necked”, so it’s amazing to see they’re at the low end of the spectrum with necks only 23% T–L. Contemporary sources almost always describe Leopard Seals as “long necked”, however their necks are only 29% T–L, so perhaps “thin-necked” would be a more apt description. The extinct seal Acrophoca is also typically described as “long-necked”, although judging from this skeletal illustration and mounted specimen, the neck is around 30% T–L. The closest true seals have to long necks come from members of the “tribe” Phocini (Phoca, Pusa, Pagophilus), although I have no idea why that would be the case.
* Piérard (1971) cites a source giving 35% for Harbor Seal T–L, so my figure above is probably a shorter-necked young individual.
Northern Fur Seals (Callorhinus ursinus) at Mystic Aquarium.
As for otariids (“eared seals”) — sometimes described as having “snakelike” necks (e.g. Riedman 1990) — do they truly have long necks, or is this a deception from thin necks held out straight? Otariids require a considerable amount of mass before and after their foreflippers (their source of propulsion) for stability, and so they keep their necks out fairly straight (King 1983). Phocid and otariid necks have been described as “similar” in length (Rommel & Reynolds 2002), although just to be on the safe side, I’ll quantify this as well:
Same deal as before, but now with: Walrus (Odobenus rosmarus), Australian Sealion (Neophoca cinerea), Australian Fur Seal (Arctocephalus pusillus doriferus), California Sealion (Zalophus californianus), Steller’s Sealion (Eumetopias jubatus), Northern Fur Seal (Callorhinus ursinus).
Otariid necks vary little, from 34.5% T–L in Australian Sealions (and most other being only slightly higher) to 41% T–L in Northern Fur Seals. So there is certainly quite a pronounced difference in neck length between Bearded Seals and Northern Fur Seals, it does not seem that the average phocid, otariid or walrus is not truly that different in neck length. It should be cautioned that proportional neck length can change considerably during maturity, so there is certainly some error in these figures. The Bearded Seal was reportedly an old female (Hayden 1880) so if anything, it may have had a longer neck than average.
One thing I haven’t mentioned so far is that pinnipeds have far longer tails than most observers would expect, ranging from 13.5% T–L in Northern Fur Seals to 41% T–L in Ringed Seals. I really have no idea why this would be the case.
References:
Allen, J. (1880) History of North American Pinnipeds. Available.
King, J. (1983) Seals of the World.
Piérard, J. (1971) Osteology and Myology of the Weddell Seal Leptonychotes weddelli (Lesson, 1826). Available. IN: Burt, W. (editor) Antarctic Pinnipedia.
Riedman, M. (1990) The Pinnipeds: Seals, Sea Lions, and Walruses.
Rommel, S. & Reynolds, J. (2002) Skeletal Anatomy IN: Perrin, W. et al. (eds.) Encyclopedia of Marine Mammals. Relevant Passage.
| Skull | Cerv. | Thor. | Lumb. | Sac. | Caud. | |
| Dog (King) | ? | 17.00% | 24.00% | 18.00% | 4.00% | 37.00% |
| Bearded (Hayden) | 230 | 250 | 800 | 390 | 175 | 350 |
| Weddell (Piérard) | 0 | 274 | 820 | 385 | 150 | 385 |
| S. Elephant (Hayden) | 480 | 570 | 1690 | 670 | 250 | 680 |
| Leopard (King) | ? | 17.00% | 37.00% | 22.00% | 3.00% | 21.00% |
| Hooded (Hayden) | 265 | 275 | 630 | 320 | 190 | 290 |
| Harbor (Hayden) | 220 | 210 | 445 | 216 | 120 | 230 |
| Ringed (Hayden) | 163 | 200 | 410 | 190 | 100 | 245 |
| Harp (King) | ? | 19.00% | 37.00% | 17.00% | 7.00% | 21.00% |
| Walrus | 390 | 400 | 1170 | 380 | ? | 550 |
| N. Fur (Hayden) | 275 | 430 | 770 | 270 | 160 | 140 |
| N. Fur (Hayden) | 245 | 360 | 680 | 245 | 145 | 145 |
| N. Fur (Hayden) | 200 | 200 | 520 | 185 | 105 | 160 |
| N. Fur (Hayden) | 185 | 172 | 470 | 173 | 95 | 120 |
| Aus. Sealion (King) | ? | 20.00% | 43.00% | 15.00% | 7.00% | 15.00% |
| Aus. Fur (King) | ? | 21.00% | 44.00% | 15.00% | 6.00% | 13.00% |
| Cal. Sealion (Hayden) | 236 | 320 | 640 | 230 | ? | 280 |
| Steller’s (Hayden) | 374 | 500 | 1050 | 340 | ? | 440 |
| Steller’s (Hayden) | 385 | 540 | 1090 | 400 | ? | 520 |
Data from King (1983) were in percentage of the entire spine with no data on skull length. Some Data from Hayden (1880) is in millimeters, and for instances where sacral and caudal vertebrae were lumped, I signified this with “?” in the area for sacral measurement.
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.
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.
From Wikipedia Commons
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.
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
From Fathinia et al. (2009)
In 1968, the Second Street Expedition across Iran collected what appeared to be a Persian Horned Viper with a Wind Scorpion attached to its tail. Examination of the specimen in 1970 revealed the apparent arachnid was actually a growth, but it could not be determined if it was some sort of reaction to a parasite, a tumor, or caused by genetics. A second specimen bearing a pseudo-arachnid was captured in 2001, and it became apparent that an entire species possessed this trait — Pseudocerastes urarachnoides (Bostanchi et al. 2006) Two live specimens were collected in 2008 and the tails were filmed in action:
An unnervingly convincing Wind Scorpion probably doesn’t seem very appealing to most humans — if urban legends about “Camel Spiders” are anything to go by — but Bostanchi et al. (2006) hypothesized the heavily modified tails are used as lures. To test this hypothesis, Fathinia et al. (2009) introduced a chick to an enclosure containing a snake; after half an hour the bird pecked the knob-like portion of the tail, was drawn in towards the head, and was struck and killed. The only animals P. urarachnoides has been known to prey on so far are birds, although it hasn’t been ruled out that other potential Wind Scorpion predators such as small mammals and reptiles are also sometimes taken (Fathinia et al. 2009). Aside from the confirmation of a caudal lure, examination of live specimens also revealed the scales are far more prominent than those of any other Iranian snake, possibly due to either the body being inflated or dermal muscles (Fathinia et al. 2009).
The awesomely rugged head of Pseudocerastes urarachnoides, from Fathinia & Rastegar-Pouyani (2010).
There is undoubtedly much about the biology of the Arachnid-Tailed Snake* that remains to be learned. The extent of its range is not certain, although it was recently discovered to overlap with two other Pseudocerastes species (Fathinia & Rastegar-Pouyani 2010). These “Gypsum Snakes”, as they’re known to some locals, are found in hills primarily made of gypsum and are hypothesized to ambush prey from bushes located near their burrows; however, there are anecdotes about them also ambushing prey from trees (Fathinia et al. 2009). I, for one, would be quite curious about any other “ethno-known” traits of this snake and how they stack up with reality.
* I’ve seen the name “Spider-Tailed Horn Viper” used, but the lure isn’t unambiguously spider-like. One local name is “Feathered Snake”, which is curious considering its diet.
Pseudocerastes urarachnoides by Omid Mozaffari. Public Domain image.
References:
Bostanchi, H. et al. (2006) A New Species of Pseudocerastes with Elaborate Tail Ornamentation from Western Iran (Squamata: Viperidae). Proceedings of the California Academy of Sciences 57(14) 443—450. Available
Fathinia, B. et al. (2009) Notes on the Natural History of Pseudocerastes urarachnoides (Squamata: Viperidae). Russian Journal of Herpetology 16(2) 134—138. Available
Fathinia, B. & Rastegar-Pouyani, N. (2010) On the species of Pseudocerastes (Ophidia: Viperidae) in Iran. Russian Journal of Herpetology 17(4) 275—279. Available
A new look for Makaracetus bidens
In Trunks, Proboscides & Makaracetus, I argued the extinct whale Makaracetus bidens probably didn’t have a “trunk” or “proboscis”, contra Gingerich et al. (2005). For one thing, an overhaul of terminology resulted in ‘trunk’ no longer referring to a nasal appendage, ‘proboscis’ being restricted to tubular nasal/lip structures capable of grasping food, and all other elongate nasal structures being termed ‘prorhiscis’ (Milewski & Dierenfeld 2013). Makaracetus certainly had over-developed facial features compared to its cetaceous relatives, but it didn’t appear any more likely to have a “trunk” than, say, a camel.
Boar skull, courtesy of Markus Bühler.
One feature of Makaracetus I didn’t discuss in the last round were its maxillary fossae, which Gingerich et al. noted were also present in pigs. This feature is plainly visible on the boar skull above — it’s the virtual trench running from the orbits down the snout. These fossae provide attachment for the maxillolabialis superior and inferior, which are responsible for moving the protruding snout (Gregory 1920).
Pig snout musculature. From Gregory (1920)
What’s interesting is that pigs almost fit the definition of having a proboscis. Pigs can apparently grasp food items with both their nose and lip musculature, but fall short of the definition since only the disc is mobile (Milewski & Dierenfeld 2013). Does this mean Makaracetus may have had some sort of proboscis after all? Probably not. It’s notable that one trait shared by proboscides owners is directional olfaction (Milewski & Dierenfeld 2013), which seems like an unlikely trait for a cetacean to evolve, considering they lack the ability to smell underwater. Furthermore, pigs don’t have exclusive rights to maxillary fossae.
Top: Makaracetus from Gingerich et al. (2005)
Middle: Potamochoerus sp. from Gregory (1920)
Bottom: Macropus sp. from Gregory (1920)
Kangaroo maxillary fossae bear a surprising resemblance to those of Makaracetus — they’re similar in extent, only present anterior of the antorbital foramen, and are on the lower half of the rostrum. Unlike pigs, the maxillary fossae of kangaroos provide an origin for part of the buccinator muscle (Gregory 1920). The fossae are also present in baboons, where I suspect they have something to do with this display. Maxillary fossae also appear to be present in llamas but apparently not camels, for some reason. Considering the apparently variable functions of maxillary fossae and the additional premaxillary fossae of even more mysterious purpose, I’d agree with Gingerich et al.’s interpretation of “hypertrophied facial muscles” for Makaracetus and hesitate to speculate much further.
So if the nose of Makaracetus didn’t bear a proboscis or prorhiscis, what did it do? Perhaps the expanded nasal vestibule was merely a side effect of the snout warping into a down-turned shape. Another parallel could be found in Gray Seals, which have nasals retracted to a similar degree as Makaracetus and enlarged noses which function as displays (Miller & Boness 1979); however more specimens will be required to conclude that the trait was sexually dimorphic. Milewski & Dierenfeld (2013) hypothesized that the enlarged nose of Moose may act as a buoy to counterbalance to forelimbs when foraging underwater, a trait which could be beneficial to the apparently benthic-feeding Makaracetus. However, Makaracetus appears to have a much smaller nasal chamber than Moose, so the potential benefits could have been minimal.
I reconstructed Makaracetus as a Hippo/Manatee/Walrus-thing up top, but I suspect my endeavors were far too conservative. Makaracetus was a beast without obvious parallels and its true appearance can probably never be known. Still, there’s no reason to go slapping a “trunk” on strange-looking skulls, and I hope Milewski & Dierenfeld (2013) will get the attention it deserves and open minds to the myriad other possibilities of big, weird noses.
References:
Gingerich, P. et al. (2005) Makaracetus bidens, a New Protocetid Archaeocete (Mammalia, Cetacea) from the Early Middle Eocene of Balochistan (Pakistan). Contributions from the Museum of Paleontology 31(9) 197—210. Available
Gregory, W. (1920) Studies in comparative myology and osteology, No. V. — On the anatomy of the pre-orbital fossæ of Equidæ and other ungulates. Bulletin of the American Museum of Natural History 42 265—283. Available
Milewski, A. & Dierenfeld, E. (2013) A structural and functional comparison of the proboscis between tapirs and other extant and extinct vertebrates. Integrative Zoology doi: 10.1111/j.1749-4877.2012.00315.x
Miller, E. & Boness, D. (1979) Remarks on display functions of the snout of the grey seal, Halichoerus grypus (Fab.), with comparative notes. Canadian Journal of Zoology 57 140—148. Available
The terms ‘trunk’ and ‘proboscis’ have been applied to a heterogeneous array of bits danging off vertebrate faces such as the bulbous nose of male Proboscis Monkeys, the pendulous resonating chamber of male Elephant Seals, the hydrostatic facial tentacle of proper elephants, and even the chins of Elephantnose Fish. Milewski & Dierenfeld (2013) argue the terminology has become “dysfunctionally vague” and in need of a massive overhaul. The authors trash the term ‘trunk’ as it is vague and redundant (being a synonym for ‘torso’) and lacks precedence over ‘proboscis’, which was originally applied to elephants and roughly translates as ‘forager’. Due to this etymology and the extreme morphology exhibited by elephants, the term ‘proboscis’ was redefined to be a tubular extension of nasal and lip musculature capable of grasping food (Milewski & Dierenfeld 2013). The only extant non-Proboscideans to fit this definition are tapirs, and while numerous extinct mammals have been interpreted with proboscides (Palorchestes, Cadurcodon, Brachycrus, Macrauchenia, Pyrotherium) only Astrapotherium has a good case for having a proboscis under this new definition, since it doesn’t appear to have been capable of feeding itself otherwise.
This Mountain Tapir demonstrates that if narial tubes are wrapping around food, it’s a proboscis. From Wikipedia Commons.
As for other nasal structures that are incapable of grasping food, those have now been termed ‘prorhiscis’. These, uh, ‘prorhiscides’ (?) have disparate functions ranging from a directional sense of smell in Elephant-Shrews, dust filtration in Saiga, thermoregulation and water conservation in Dik-Diks, amplification of roars in Elephant Seals, and possibly acting as a buoy for diving Moose (Milewski & Dierenfeld 2012). There are other weird structures formerly labeled ‘proboscis’ in fish, but that’s really a story for a different time.
The snout of a Saiga rivals that of Tapirs in length, but does not incorporate the lips or grasp food, and is thus a prorhiscis and not proboscis. From Wikipedia Commons.
Gingerich et al. (2005) interpreted the extinct whale Makaracetus as having a “trunk” or “short, muscular proboscis” but confusingly referenced tapirs, manatees and walruses as “imperfect models”. Were they proposing an elephantine proboscis, prehensile lips, or something in between? This is a great example of how the now-archaic terminology was “dysfunctionally vague” and in light of Milewski and Dierenfeld’s efforts, it’s time for a reassessment.
Dorsal and lateral views of: Makaracetus (top) from Gingerich et al. (2005); Artiocetus (bottom) from Gingerich et al. (2001)
Makaracetus is classified as a protocetid and appears fairly similar to species such as Artiocetus (above), although with four pronounced differences: a nasal vestibule extending to the end of the snout, a downward-deflected rostrum with two rather than three pairs of incisors, “extraordinary” fossae (labeled LFM, LFP above) suggesting massive facial muscles, and enlarged antorbital canals (labeled AF above) indicating increased blood supply to the end of the snout (Gingerich et al. 2005). Clearly something odd was growing on the face of Makaracetus, but without living protocetids, it’s a bit hard to tell just what. I’m not even certain if a Tapir-style proboscis can be distinguished from a prorhiscis without live specimens, so, unfortunately, it appears there’s just no way of knowing things for certain. That won’t stop me from rampantly speculating.
Top: Makaracetus
Second: Brazilian Tapir from Witmer et al. (1999)
Third: West Indian Manatee from Husar (1994)
Last: Walrus from Wikipedia Commons
Imperfect models indeed. Gingerich et al. (2005) compared Makaracetus and Tapirs on the basis of expanded nasal vestibules, however, the nasals of Makaracetus are only around half as retracted. Makaracetus and Manatees were compared on the basis of being aquatic and having down-turned rostrums, which Gingerich et al. suggested to be an indicator of benthic feeding. Walruses were suggested as an ecological model, namely as a species that uses facial muscles to prey on bivalves, despite having some very different anatomy. The proposed ecology seems reasonable — although it requires better-known teeth to confirm — but as for what was happening with the nose of Makaracetus, there are some more interesting models.
Dromedary from Harvard Museum of Natural History.
Superficially, Makaracetus looks kinda camel-y. The rostra of the two species, while differing considerably in depth, appear to be deflected downward at a similar relative place and to a similar degree. Camels have one less pair of incisors than Makaracetus and, oddly, the placements of the remaining incisor pair, canine, and first premolar are comparable. The antorbital foramen (“AF”) of the camel appears to be larger than that of Makaracetus. There are of course several pronounced differences between the two, namely, the fossae in Makaracetus (LFM, LFP) do not appear to have equivalents in camels and, perhaps as a result of these structures, Makaracetus has a rostrum that looks spoon-like when viewed above and camels don’t. Makaracetus and camels undoubtedly had enlarged noses for very different reasons, but this comparison makes a proboscis or even prorhiscis seem unlikely in the whale.
But I’m not quite done with Makaracetus yet, I haven’t even talked about pigs and moose! That will have to wait for a followup to this increasingly out-of-control article.
References:
Gingerich, P. et al. (2005) Makaracetus bidens, a New Protocetid Archaeocete (Mammalia, Cetacea) from the Early Middle Eocene of Balochistan (Pakistan). Contributions from the Museum of Paleontology 31(9) 197—210. Available
Gingerich, P. et al. (2001) Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan. Science 293 2239—2242. Available
Husar, S. (1978) Trichechus manatus. Mammalian Species 93 1-5. Available
Milewski, A. & Dierenfeld, E. (2013) A structural and functional comparison of the proboscis between tapirs and other extant and extinct vertebrates. Integrative Zoology doi: 10.1111/j.1749-4877.2012.00315.x
Witmer, L. (1999) The proboscis of tapirs (Mammalia: Perissodactyla): a case study in novel narial anatomy. Journal of Zoology 249 249—267. Available
If the occasional Caperea really does have a supernumerary dorsal fin, it would only be a minor anomaly compared to the skeletal madness within:
Caperea (top) from Bisconti (2012).
Fin Whale (below) from Wikipedia Commons.
Caperea has vertebrae counts and proportions that are strikingly different from any other whale. Cetaceans have four types of vertebrae: cervical (neck), thoracic (with ribs), lumbar, and caudal (tail, with chevrons sticking out below); unlike most mammals, there are no sacral vertebrae, which articulate with the hips. Perhaps the most striking difference between Caperea and the Fin Whale (Balaenoptera physalus) is the relative size of the ribcage. Caperea has 17 to 18 thoracic vertebrae, more than any other cetacean, but not much more than Fin Whales, which have 14 to 15 (Buchholtz 2010, True 1904). The extra length of the ribcage is thus mostly due to the elongation of the thoracic vertebrae themselves (Buchholtz 2010) and as a result, the relationship between vertebrae count and length is unlike that of any other cetacean (Buchholtz 2007). Another striking trait of Caperea is the very low number of lumbar vertebrae, with most individuals having one and one individual having none (Buchholtz 2010). In other words, Caperea has a tail coming (almost) straight out of its ribcage. Comparatively, Fin Whales have 14 to 16 lumbars (True 1904) and no other baleen whale has fewer than 10 (Tinker 1988). The River Dolphin Inia reportedly has as few as three lumbars, but it also has 13 thoracic vertebrae (Best & da Silva 1993), which is totally normal. It is likely there are some functional similarities shared between Inia and Caperea, but the proportions of Caperea reminded me more strongly of another aquatic mammal, and it’s not a cetacean.
Caperea (top) from Bisconti (2012)
West Indian Manatee (below) from Wikipedia Commons.
Yes, a manatee, Trichechus manatus. Bear with me here. There are 17 to 18 thoracic vertebrae and 1 to 2 lumbars (Buchholtz et al. 2007), which overlaps with Caperea. The thoracic vertebrae are also elongate (Buchholtz et al. 2007) and judging from the comparison above, it’s roughly to the same degree as Caperea. However, the patterning is not quite the same, since the longest vertebrae in Caperea are near the thoracic/lumbar/caudal region and those of the manatee are about mid-thoracic (Buchholtz et al. 2007; Buchholtz 2010). The ribs of both species are also quite wide, particularly the posterior ones. Unlike Dugongs, Manatees lack sacral vertebrae (Buchholtz et al. 2007). These are some curious parallels, and a purposefully ignorant reconstruction of Caperea as a whale-a-tee was all but inevitable:
Contrary to what hypothetical future (or alternate universe?) palaeontologists may think, Caperea doesn’t look like a manatee at all. It pretty much looks like a Minke with an arched jaw.
Stranded Caperea, from Te Papa’s Blog.
Not only does Caperea look nothing like a manatee in life, it also doesn’t obviously function like one, being oceanic and reportedly a fast swimmer (Kemper 2009). Caperea is reportedly highly flexible (Kemper 2009), as is Inia (Fish 2002), so this makes me wonder if lumbar reduction results in a more flexible body, and that perhaps Caperea and manatees achieved this through a similar mutation. As documented in the three-part series from Tet Zoo (Part 1, Part 2, Part 3) Caperea has other bizarre morphology not shared with other cetaceans or manatees including huge and overlapping transverse processes as well as ribs that appear curiously loosely-connected. As for why it has any of this morphology or would need to be flexible, I have no idea.
Te Papa’s Blog has lots of entries documenting the dissection of a juvenile Caperea, and it is really invaluable for seeing how the soft tissue and skeleton fit together. It’s certainly interesting that soft tissue doesn’t necessarily mean that animals were weirder than their skeletons would indicate, some externally look far more “normal” than they have any reason to.
References:
Best, R. & da Silva, V. (1993) Inia geoffrensis. Mammalian Species 426, 1—8. Available
Bisconti, M. (2012) Comparative osteology and phylogenetic relationships of Miocaperea pulchra, the first fossil pygmy right whale genus and species (Cetacea, Mysticeti, Neobalaenidae). Zoological Journal of the Linnean Society 166(4) 876—911. Supplement available
Buchholtz, E. (2010) Vertebral and rib anatomy in Caperea marginata: Implications for evolutionary patterning of the mammalian vertebral column. Marine Mammal Science. Available
Buchholtz, E. et al. (2007) Vertebral anatomy in the Florida manatee, Trichechus manatus latirostris: a developmental and evolutionary analysis. Anatomical Record 290(6) 624—637.
Buchholtz, E. (2007) Modular evolution of the Cetacean vertebral column. Evolution & Development 9(3) 278—289. Available
Fish, F. (2002) Balancing Requirements for Stability and Maneuverability in Cetaceans. Integrative and Comparative Biology 42(1) 85—93. Available.
Kemper, C. (2009) Pygmy Right Whale IN: Perrin, W. et al. (eds.) Encyclopedia of Marine Mammals.
Tinker, S. (1988) Whales of the World. Partially Available
True, F. (1904) The whalebone whales of the western North Atlantic. Smithsonian Contributions to Knowledge 33 1—332. Available
Compared with terrestrial predators, the ~90 species of cetaceans (WoRMS 2012) ranging from wolf-sized to the largest animals ever, are a mind-boggling array. They’re the Pleistocene megafauna that, until recently, survived mostly intact (Anderson 2001) and no place on land, even Recent sub-Saharan Africa, can really compare with our oceans. It’s shocking that on top of this vast menagerie, one author claimed as many as 15 species remain to be discovered, including exotic beasts such as an 18 meter baleen whale with two dorsal fins (Raynal 2001). In a previous article I argued that particular hypothetical species, Amphiptera pacifica, was far more likely to be an early observation of (an anomalous?) Caperea than anything new and began to wonder if the discovery of unmistakable new species is at all probable. It isn’t.
Biological Marginalia 
