The Hero Shrew!

I think that I've had my fair share of cryptozoology and anecdotal evidence. Things don't have to be gigantic or monstrous or poorly supported to be interesting. Being incredibly unusual helps though. I remember reading Walker's Mammals of the World a while back and coming across a strange account of a species of shrew able to withstand a man standing on it with no ill effects. An accompanying picture showed an absolutely bizarre spinal column with "armor" mostly on the thoracic vertebrae. With the magical power (to me) of access to journals both home and abroad, I've been able to track down the supremely named Hero shrew, Scutisorex somereni Thomas 1910.

Despite being so strange, the unique spinal morphology wasn't recognized until 7 years after the shrew was described and little information was learned for the next 80 years (Cullinane et al., 1998). There seems to be a long history of interesting things being found in Museums, of all places. Scutisorex was hypothesized to be related to the genus Sylvisorex judging by dental characteristics, although molecular evidence suggested that it diverged from Sylvisorex cf. konganensis and S. ollula in the mid-late Miocene (Querouil et al., 2001). The paper notes that the morphology of shrews is difficult to interpret clade-wise, so a polyphyletic genus is not a surprise - the possibility that the hero shrew is not even a distinct genus is shocking. The spinal column is remarked upon as being the most modified among vertebrates (Cullinane & Aleper, 1998); that evolving within a genus would be astounding. More molecular studies will probably clarify the position of the hero shrew, but regardless it seems that the unique spine evolved very suddenly. Something definitely punctuated the equilibrium here.

So what exactly is so unique about the hero shrew's anatomy anyways? Wikipedia's image demonstrates that this armored shrew is completely unremarkable looking externally and looks roughly similar to anything else that is small, mammalian and scampers around. The spinal column is a different matter entirely. The vertebrae count is the mammalian norm for the cervical (7), thoracic (14), and sacral (5) regions, although the lumbar region has 11 vertebrae, as opposed to the normal 5 (Churchfield et al., 2007). I'd be curious what sort of mutation led to this not-quite-doubling of vertebrae. In the mid to end thoracic and lumbar regions the vertebrae have been fundamentally modified: the lateral part of the vertebral arch have been modified into interlocking bony plates (Churchfield et al., 2007). Cullinane et alii's noted that a wide range of mammals (rodents, "insectivores", a didelphid and a gray "fox") studied had spines taking up 1.08% the body mass on average (all within one standard dev.), while this shrew's spine took up 3.97%, seven standard deviations above the mean. The ribs and skull are also more robust than is expected, although the appendicular skeleton is not. While fossorial mammals typically deal with loads by developing the appendicular skeleton; anecdotal and structural evidence indicates that this hero shrew can withstand enormous pressure, reported at 1000 times the mass of the shrew. In an accompanying paper, Cullinane & Aleper discuss the spinal musculature, something which has of course also been undescribed beforehand and hindered mechanical analysis. The most radical change was that the transverse spinalis group has been reduced, apparently due to the tubercles on the spine resisting torsion and shear, which the muscle group does in other mammals. Some of the other spinal muscles were also highly modified and the authors suggested that they could be considered new groups. Cullinane and another author (Bertram) later studied the intervertebral joints of the species and noted that the spine represents the only known bone-on-bone articulation in mammals and is capable of withstanding 4-5 times more torsion than a normal mammalian spine. While the specifics of the mechanics involved in these tests is out of my league, it is clear that this is one remarkable animal.

Taken from Cullinane & Bertram, 2000, Fig. 1. The genetic testing revealed Crocidura to be a fairly close relative, and shows the normal shrew, and to some degree mammalian, condition.

Why this species has such a modified spine is a mystery. The species is only present in the Eastern Democratic Republic of Congo and neighboring Rwanda, Burundi and Uganda where it is not common (and rather elusive) (Churchill et al., 2007). Churchill et alii's study attempted to determine the spinal modifications by determining its diet and thus determining its habitat. This large shrew species was found to be opportunistic but focused on earthworms, a rare trait for an African shrew but common in large temperate species. With its unspecialized limbs and diet, it was determined to be a partially subterranean (not fossorial) feeder, like many other shrews. The only possible specialization for this way of life was an unusually long digestive tract (possibly to digest worms), although the spine/rib modifications were not explainable.

Cullinane & Bertram wondered that if there were no known behavioral or ecological correlation to this structure, which there don't seem to be, then "perhaps complex morphologies can evolve without selection driving their adaptive trajectory." This is a rather astounding idea, what if the cause of the bizarre spine morphology is nothing more than a few simple mutations? Does it give any benefits to this species? Since it is noted as being uncommon, perhaps it doesn't...or perhaps it is recent enough that benefits are not entirely apparent. Maybe if given enough time this could evolve into a distinct group of mammals - Cullinane et al. 1998 conjecture that "this species may represent a breakthrough in the morphology of the tightly constrained structure that is the mammalian spine". That is an awfully exciting idea, a future radiation of mammals started by the Hero Shrew! Or not, it could always be an evolutionary dead end, a bizarre evolutionary "experiment" of sorts. If this truly did evolve within a genus, or at least very closely related to species, then it may represent an absolutely fascinating case study in punctuated equilibrium.

I can tell that something is up with me that I'm more far excited by this shrew than the notion of a super-gigantic-snake-mimicking-Amazon-archeocetes or whatever. What have I become...

References:

Churchill, S. 2007. Feeding ecology of the armored shrew, from the north-eastern Democratic Republic of Congo. Journal of Zoology 273, 40–45. Available: Here

Cullinane, Dennis M. et al. 1998. The functional and biomechanical modifications of the spine of Scutisorex somereni, the hero shrew: skeletal scaling relationships. J. Zool., Lond. 244, 447 -452. Available: Here

Cullinane, D. M. & Aleper, D. 1998. The functional and biomechanical modifications of the spine of Scutisorex somereni, the hero shrew: spinal musculature. J. Zool., Lond. 244, 453-458. Available: Here

Cullinane, Dennis M. & Bertram, John E. A. 2000. The mechanical behaviour of a novel mammalian intervertebral joint. J. Anat. 197, pp. 627-634. Available: Here

Querouil, Sophie et al. 2001. Phylogeny and Evolution of African Shrews (Mammalia: Soricidae) Inferred from 16s rRNA Sequences. Molecular Phylogenetics and Evolution. Vol. 20, No. 2, pp. 185–195. Available: Here

This is what Conway Morris actually believes.

The history of Supersnakes and historical Python sp. range.

One of the major catalysts for my previous post was discovering that a supersnake hypothesis of sorts had actually made it into an academic journal. Unlike reports of outsized boids in the 20-30 foot (6-9 m) range, supersnakes are far outside the recorded or projected maximums. It has been hypothesized that supersnakes are a new subspecies or species, possibly a Pleistocene relict or even a non-snake. Distinctive characteristics suggesting a new species outside of size are rare, and it should be noted that large snakes are prone to wild exaggeration. Murphy & Henderson mention that large snakes already have mechanical problems, so a theoretical supersnake would have to overcome pumping blood to extremities and blood pooling in the tail. Rectilinear locomotion will presumably become impractical at some size, so a supersnake may also have to be entirely aquatic. Unless one presumes that Gigantophis* has had unrecorded examples of very outsized specimens, there is nothing to indicate a snake or snake relative has gotten much larger than 10 meters. So for numerous reasons I find it extremely improbable that one of the largest living or recently living animals is an undiscovered species of extremely big snake.

*Not in the snake crown group, although it was a constrictor. Mosasaurs, which aren't are a sister group to snakes, were the largest squamates at 15 meters long.

Stothers 2004 did not discuss the mechanical or ecological implications of supersnakes, but instead suggests that a population of large pythons existed in Northern Africa and Southwestern Asia - where they do not live today. Another focal point of this paper is that historical evidence of giant snakes (aside from mythology and interpreted animal remains) has had a huge effect on serpent lore. Since this affects the history of the sea serpent and perhaps the giant anaconda reports, this should be of interest to cryptozoology. The author rhetorically asks if we are "dealing with zoology or cryptozoology", although to me it clearly falls into the latter category (as we shall see). Peer reviewed articles on cryptozoology, in journals I can find, are exceedingly rare, so I find the very existence of this article interesting. Oh yes, and it mentions the cetacean centipede.

Ancient literature on giant serpents is apparently quite sparse until the Bagrada river incident of 256 B.C. where Regulus and his troops met a monstrous serpent. After it ate several men, it was fired at with javelins and darts which had no effect. Eventually its spine was crushed with a rock fired from a ballista and it was overcome with spears. When it died, according to one author, its corpse polluted the landscape for a considerable time. The 120 foot skin was then brought to Rome, allegedly measured under the instruction of the Senate, and was viewed as "an object of wonder to all". The description of the "feet of the ribs" (which don't actually move) made it clear this was a boid using rectilinear locomotion, although aside from that observation I do not find most of this story trustworthy. The story was apparently used to foreshadow the defeat and capture of the general in the following year by some, making it something of a legend. The detail of it repelling darts (or arrows) and javelins also seems rather unrealistic. I agree with Stothers that we can probably discount that this was an outright fabrication or that the animal actually was numerous crocodiles, the anatomical details hint at a real snake being involved somewhere. The author suggested that the length in feet may have been confused for rib "feet" somewhere along the line. The world's largest snake skeleton (22 feet, 26 originally) appears to have far in excess of this number, so I find this possibility very unlikely. The final option, the one Stothers plumps for, is that snakes two millennia ago actually could reach 120 feet in length. He probably should have discussed exactly how big a "foot" back then was anyways, and that snake skins can be stretched to 140% the original length while carefully avoiding stretching (Murphy & Henderson 1997 p.25). After reading through the reports, I've become cynical enough to suggest at least a preserved skull (and preferably the rest of the skeleton) to demonstrate snake size.

Size is not the only issue involved, the presence of a large snake (Python sp. ?) near the Mediterranean is remarkable enough as it is. Supposedly Ptolemy II Philadelphus had a 45 foot "Ethiopian" snake, although he may have actually had 21 and 19.5 foot snakes. Stothers suggests that the lengths may have been combined (and further exaggerated), and if this actually was a trend it could have huge implications for the other stories. This and other stories from Africa and Arabia support the notion of large indigenous pythons.

India is known to have giant snakes (Python molurus), but Stothers discussed stories from this region regardless. During Alexander the Great's conquests in the sub-continent, a king supposedly possessed two snakes well over 100 feet, although since only the "head" was seen, Stothers thinks this may have been something of a joke. Alexander himself supposedly displayed a 75 foot long snake, but Stothers suggests that this and other large reports may have been something of a "circus-show hyperbole". In one incident a report of the maximum size of Indian snakes was exaggerated from 24 feet to...500 feet! This might even be worse that giant squid claims. While there's nothing to suggest a range or size extension, these stories of "ox-swallowing and elephant-toppling" snakes undoubtedly had an effect on the image of giant "serpents".

Apparently this fifth century B.C. Greek gem was meant to show a connection between snake observations and serpent legend - I don't see how.The crest and structures behind the "neck" suggest and oarfish to some degree (and its pelvic fins). I assumed the archetype for a maned serpent originated much later and further up north...

As the above picture indicates, Stothers moves from "terrestrial" serpents to sea serpents. He says that ancient reports of sea monsters rarely resembled modern ones (the above one excluded apparently) and had a variety of causes. "Large snakes" or the impression of them, can theoretically be caused by some sort of weather phenomenon, large fish and whales. While not relevant to our theoretical population, this still effects the image of supersnakes. I must comment upon Stothers insistence that fish continue to grow until they die - even if a fish continued to add weight at a steady rate (which I really doubt) the cube law would make the fish grow less and less per amount of weight added. His reference to "some prehistoric sharks" reaching 100 feet in length (!) is either an incredibly outdated reference to C. megalodon or related to Richard Ellis' suggestion that Parahelicoprion grew that large (A notion I have never heard discussed or mentioned elsewhere). Despite the subject, Zoology isn't really too focused upon in this paper. The author's affiliation with NASA and very little information online about him puzzles me even further...

Oh yes, the Scolopendra aka cetacean centipede aka many-finned makes an appearance. Two rarely mentioned references are mentioned: the rib of a thousand-footed specimen from Italy was mentioned by Theodoridas and another mutilated 48-foot specimen mentioned by Antipater. Stothers mentions speculations that it (Aelian's original mention) may have been a 120 foot whale with suckfish attached to a belly or ripples appearing as if many fins are at work. The giant squid was mentioned as a (dubious) candidate, demonstrating its inevitability while discussing sea monsters. Despite the author's claim, one group of extinct fish did have numerous fins, although it is undoubtedly a coincidence. Exactly why this bizarre creature was mentioned is not very clear. It is later suggested to be "possibly related" to African serpents, despite not really being described as serpentine. The only possible connection I could think of is that the numerous ribs of snakes could be confused for actual appendages in a rotting carcass. The insistence that it doesn't fit in with any of Heuvelmans' categories is strange (since it was partially defined with the original sighting).

Looking over everything, I'd say this paper definitely falls under the category of cryptozoology. The discussion of snakes and snake-like creatures and their place in the development of snake lore is interesting, but I think it could have been covered in a separate paper. Tales of giant Indian snakes and cetacean centipedes and their implications lead away from what is truly interesting, a unique Python sp. population. The snakes could be relatives or members of the Indian P. molurus or sub-Saharan P. sebae (hence sp.), and it is not clear if their ranges were larger or they were actually brought over by humans. It is possible that a unique species was involved as well, and I'm surprised Gigantophis wasn't brought up (since it lived in Egypt - in the Eocene). Heuvelmans made mention of giant snakes from North Africa, which wasn't brought up either, but it appears there is more evidence to support the existence of this population. So here we go, a potential new species that allegedly reaches large sizes, a supersnake of sorts I suppose. Stothers suggests that ancient pythons may have reached larger sizes and that while there is not proof of snakes over 45 feet long, "it is hard to deny categorically that they actually existed." It is hard to deny, but also impossible to prove. As demonstrated numerous times, the size of large snakes is prone to exaggerations or outright lies. If even estimates from a few years ago can be dubious, I sincerely doubt the accuracy of reports several thousands of years old. It is possible for species in the past to have had more common large specimens, although there is no physical evidence for snakes far exceeding the maximum known sizes today. Historical evidence can have its uses in Zoology, but I think that describing new, possibly very large species is beyond what it is capable of. It does give us a clue where to look for large python bones, and all somebody has to do is dig up a few bones.


And yet again, another conclusion that we need more information to really make a conclusion.



References:

Stothers, Richard B. 2004. Ancient Scientific Basis of the "Great Serpent" from Historical Evidence. Isis. 95: 220-238. Available: Here

Murphy, John C. & Henderson, Robert W. Tales of Giant Snakes. Krieger Publishing Company; Malabar, Florida; 1997.

Giant snakes and Supersnakes of the Amazon

Here is a photograph that has actually been discussed seriously by at least one author and on the Internet of course:

A Brazilian postcard c. 1932. Note the coincidentally Gray-like profile in the background; why this hasn't sparked outlandish theorizing yet is beyond me.

Information about this alleged supersnake is rather variable, never a good sign. Heuvelmans reports it to be 30m long and 60 cm wide with a weight of 2 tons. When it was getting killed under machine-gun fire, it reared up 9 meters to crush bushes and small trees. Murphy & Henderson gives a much more detailed report of a 32 m by 1.25 m 3 ton snake with "horrid huge eyes". Both connect it to the photo. Then there is this drawing I found on Cryptomundo (no indication of source) which gives the wrong date and re-imagines this photograph to look a lot more convincing. It should be obvious to everybody why the photo didn't turn out like the drawing; should being the key word. Tim Dinsdale (whom I suspect is behind the drawing) believed that the large eyes, mouth and "thickness at the sixth convolution" indicated this to be an unknown species. Murphy and Henderson, who literally wrote the book on giant snakes, suggest it was just decomposed. Oh, and although 2-3 tons sounds like a lot, a 100 foot anaconda would weight somewhere between 10-25 tons.

Welcome to the world of giant snakes and supersnakes! Giant snakes are very large specimens of known species, while supersnakes are proposed unknown species or subspecies that have obtained extremely large sizes. Like sea serpent reports, it has been suggested that some of the supersnake legends have some rather non-snake-like characteristics, further muddling things. This covers both Zoological and cryptozoological ground, although with anecdotal evidence and mysteriously vanishing physical evidence it is more in league with the latter. Despite little evidence supporting the existence of outsized snakes, an African supersnake hypothesis of sorts has been published in a peer reviewed journal fairly recently. I'll discuss this later, but let's get back to giant anacondas.

The green anaconda (Eunectes murinus) is apparently the most massive species of snake and is frequently associated with Amazonian waterways. Murphy and Henderson consider it a giant snake (i.e. known to exceed 20 feet/6 meters), but exactly how big it gets has been a matter of dispute. Pritchard's Rule anticipates a record-sized snake is 1.5 to 2.5 times as long as the minimum adult female length (10.5 ft/3.2 m), so 8 m/26 feet is the presumed maximum for green anacondas. It should be taken into consideration that the maximum sized snake should be nearly 16 times as heavy as the minimally sized one, making for a rather impressive range. Pritchard comments that anacondas are not a rare species and thousands have been measured, and surprisingly even 20 foot specimens are considered rare. Presumably the average is somewhere around 15 feet/4.5 m; I wish publications listed averages and maximal sizes separately - before writing this I was under the impression that 20+ feet was normal. As hinted at by the first report, there have been many reports of anacondas over 9m/30 feet, and some several times even that length. So were there ever really snakes that big?

Estimating the lengths of snakes is often difficult and prone to extreme exaggeration. When one Ralph Blomberg heard about a 12 meter snake skin from an Ecuadorian military commander he was rather disappointed to find out that it actually measured 6 meters. Writer Hyatt Verrill recounted an incident where numerous people estimated the length of a coiled anaconda at 20-60 feet long - it turned out to be a monstrous 19'6" (and 360 pounds/163 kg!). Savage-Landor recounted an incident where he estimated a snake to be 100 feet long judging by girth, although it turned out to be 18'5" after it was shot and measured. It had of course swallowed an entire deer and the author speculated that immensely wide trails had a similar cause. Then there is the case of Fragrant Flower, a python that allegedly measured nearly 15 meters in an Indonesian zoo which actually turned out to be 6.5-7 meters long. So effectively eyewitness accounts of giant snakes, even at very close proximity, cannot be trusted.

Teddy Roosevelt's famous offer of 5,000 dollars for a snake exceeding 30 feet has been collected, and it is doubtful that such a specimen will ever turn up. Murphy and Henderson speculate that anacondas in the rain forest may get 7-8+ meters (23-26 feet) in length due to their need to overpower large prey, although I doubt the species can now get much larger than that. There are lots of stories about animals in the not-too-distant past attaining very large sizes (2.4 m otters, super-gigantic basking sharks, et cetera), so, unless these are all exaggerations, perhaps the green anaconda and large pythons* reached somewhat larger sizes into historical times. But 40-50+ footers, well, they're probably too outsized to be any living species.

* The Burmese (Python molurus), Reticulated (P. reticulata), and African Python (P. sebae) are of comparable if not greater length than the green anaconda, which weights more though. Their stories aren't as frequently exaggerated, nor does the same "supersnake" type story occur.

The largest fossil snake is the 9.3-10.7 meter (30-35 foot) Egyptian Gigantophis garstini, so the usual prehistoric survivor paradigm in cryptozoology doesn't really apply here. This size range, at least the lower end, appears to be reachable by outsized pythons. If this is an average length for Gigantophis though, this implies that outsized freaks of this species could have been veritable supersnakes. There's no evidence of this of course. As far as we know, the green anaconda is the most massive snake we have good evidence of, well, sometimes.

It appears that very large anacondas, both real and not, may have gotten mixed up to some degree with reports of the Sucuriji Gigante. One Father Heinz both saw and collected stories of this cryptid, which he had once mistaken for a steamship. It is allegedly incredibly fast (10-15 times as fast as a boat), was very aggressive, had phosphorescent eyes (or eye in one case), had huge teeth in its lower jaw, and pushed around vegetation mats rather than move around it. The fact that it had its mouth open at all is noted as being unusual by Murphy and Henderson. They suggest that none of these characteristics are snake-like, but don't further suggest what it could be. Heuvelmans explicitly suggests that primitive whales may be behind reports, and some of Heinz's reports do resemble sea serpent reports. Murphy and Henderson follow with an account of an alleged 56 foot anaconda that also had phosphorescent eyes (and was allegedly killed). And if you recall from the very beginning of this post, the "giant" anaconda allegedly had glowing eyes again. I don't think that there's much to support the idea of non-snakes getting intertwined into things, it just seems like people added more "horrific" characteristics to an already gigantic and potentially frightening animal. There still is a remote possibility that the Sucuriji Gigante could have been from a fourth anaconda species or a subspecies of E. murinus. But like most things cryptozoological, there's very little evidence and a lot of speculation.

I won't pretend that I can make a conclusion on this matter yet. Animals obtaining notably larger sizes into quite recent times is a frequently mentioned tend, although one I have difficulty finding documentation of. There's also the idea of a Pleistocene relict subspecies/species, although if there ever was a larger species of anaconda, I don't see it continuing to survive without the megafauna it presumably preyed upon. Is it even plausible to have a larger anaconda? Presumably it would be a specialist tapir/manatee/boto/large caiman predator. And then there's the ability of people to exaggerate the length of snakes up to five-fold. The Sucuriji Gigante is even more mysterious than oversized anacondas, although hardly a notable cryptid in its own right. It could just be based off of incredibly exaggerated anacondas. I suppose all we can do is wait and see if some monstrous sub-fossil vertebrae show up, or not.

I've barely scratched the surface on giant snake and supersnake reports from the Amazon. I'd recommend my references, particularly Murphy & Henderson, for more information on these sorts of reports. While these aren't exactly the most plausible of reports, they still are rather entertaining.

And yes, there was that one peer-reviewed article on African supersnakes I have yet to cover...

References:

Heuvelmans, Bernard. On the Track of Unknown Animals. John Wiley & Sons Limited, third English edition, 1995.

Murphy, John C. & Henderson, Robert W. Tales of Giant Snakes. Krieger Publishing Company; Malabar, Florida; 1997.

References:

Heuvelmans, Bernard. On the Track of Unknown Animals. John Wiley & Sons Limited, third English edition, 1995.

Murphy, John C. & Henderson, Robert W. Tales of Giant Snakes. Krieger Publishing Company; Malabar, Florida; 1997.

Addendum:

Señor McCormick's siesta is interrupted by an expertly (and painstakingly) rendered Sucuriji Gigante.

An Original Concept

How on earth has it been almost a month since I've last posted?

With the semester coming to a screeching halt, I suppose I just got a little too caught up in work. I haven't had time to finish any lengthy posts, all I have are quite a few extremely rough drafts. Oh yeah, and numerous papers on the death penalty, ugh.


Anyways, to use a concept you're unlikely to see anywhere else on the internet; I've decided to revolve this post around a mysterious picture:

Amyda cartilaginea. Taken from this page by Indraneil Das and Ghazally Ismail. I hope me using this is okay...

I've shown this photograph to several people, and they've had no idea what this animal is. The consensus is that it is some sort of fish (perhaps eel)-like creature, although that is far from the mark. It is....

A softshelled turtle of the family Trionychidae. To see what the whole creature looks like, go to this gallery here. Instead of writing out a full post on this group, Darren has already written an article. Yay, less work for me. As for articles directly pertaining to this species, I was unable to find any, unfortunately. However, the book Turtles of the World by Franck Bonin, Bernard Devaux and Alain Dupre (2006 edition) was able to fill me in. I was actually inspired by the head of Dogania subplana (which is even more fish-like) in the book, although I was unable to find a good image online.

This is a large species, with a carapace reaching 80 cm (~30 inches). Bonin et al list a record of a 202 kg (~450 lb) captured in Thailand in 1987, though this sounds very similar to a female Chitra captured in 1986. Even if this isn't as big as a Hoan Kiem turtle, it is still very big for a freshwater turtle, probably getting somewhere in the 30-40 kg (60-80 lb) mark.

The long snout of this and other species are due to a habit of burying themselves under sediment with only their nostrils sticking out. Softshell turtles are capable of pharygeal and cutaneous respiration, and at least some species can obtain all their oxygen from the water using these methods, see here. The "soft" shells are actually as resistant to damage as those of other turtles and they effectively allow the turtles to have a lighter shell more able to be bent by muscles (to close on the head and limbs), be more streamlined, decreased mineral needs, improved camouflage, and allow cutaneous breathing (Alibardi & Toni 2006 and Scheyer et al. 2007). So long for no literature.

Back to Amyda, it is a nocturnal, predatory species that feeds on fish, frogs, shrimp, and water insects. Although The Crocodiles and Turtles of Borneo lists it as being common, Bonin et al note it as being heavily caught for meat and medicines. For more details on the anatomy, see the previously noted link.

I'll stop right there for now. If I can find a species with more literature and an eccentric appearance, perhaps I'll write on it too sometime in the near future...


References:

Alibardi, Lorenzo and Toni, Mattia. 2006. Skin structure and cornification proteins in the soft-shelled turtle Trionyx spiniferus. Zoology vol. 109 is. 3 182-195. Available: Here

Bonin, Franck et al. 2006. Turtles of the World. The John Hopkins University Press, Baltimore.

Kitimasak, Wachira et al. 2005. Distribution and Population Status of the Narrow-Headed Softshell Turtle Chitra spp. in Thailand. The Natural History Journal of Chulalongkorn University vol. 5(1): 31-42. Available: Here

Scheyer, Torsten M. et al. 2007. A plywood structure in the shell of fossil and living soft-shelled turtles (Trionychidae) and its evolutionary implications. Organisms Diversity & Evolution vol 7 (2), 136-144. Available: Here