The Unknown Sea Serpent Classification

Debunkers have occasionally brushed aside the sea serpent phenomenon as "just" being reports of oarfish, giant squid, frilled sharks, et cetera; I highly question how many (if any) reports these casual debunkers have actually read. The public idea of sea serpents is apparently of a mythological entity rather than something that actually has some interesting reports. Oudemans and Heuvelmans were early researchers who wound up collecting hundreds of reports, some of which cannot easily be written off as hoaxes or known phenomenon. I should note that I'm by no means a credulous believer in cryptozoology, just because something can't be explained doesn't mean that it is proof of something unknown. The possibility of existence is raised because of some reports but the only way to confirm existence is through physical remains. This is a very odd state of being, seemingly real but maybe not, and is possibly the reason why people clump into believers and non-believers. I'll attempt to take a skeptical (i.e. critical) approach to the subject, in my opinion the most fair way of dealing with it.

With only one possible exception, the only plausible evidence for sea serpents comes anecdotal reports. So what merit can anecdotal evidence have? After dealing with historical giant snake reports, I'm suggesting that any pre-science "evidence" be treated as a curiosity and nothing more. Even the more recent reports tend to be vague and/or suspect most of the time, but once in a while there is a remarkable sighting that is detailed and appears credible. Like the Valhalla and the Daedalus sightings, for instance. More vague reports can possibly be used to indicate possible range for sea serpents, but I'd suggest even that may be stretching credibility. The better sea serpent sightings can be plausibly compared to the occasional reports of beaked whales not fitting any known species by scientists. In the past unknown forms were seen (Mesoplodon sp. A, Tropical Bottlenose Whale) and then classified (Mesoplodon peruvianus, Indopacetus pacificus) when physical evidence showed up or was examined more closely. Some species, such as the apparently distinctive M. traversii, have not been observed to date, so a low number of sightings alone isn't a good indication against existence. The fact that sea serpent sightings have only very rarely been observed by scientists and the fact that they seem to be highly derived from any known group means that the anecdotal evidence should be scrutinized much more than the ziphiids though.

After collecting and sieving through reports of anomalous marine animals, the next logical step is to try and determine exactly what was sighted. Anthonid Cornelis Oudemans proposed a single species of, uh, "viverrine"/otter/pinniped/Basilosaurus relative behind the sightings. The proposed family tree looked odd even for that time period (Basilosaurus as a Carnivoran!?!) and this marks a trend of researchers stretching palaentological evidence to fit their proposals. A few decades later Heuvelmans decided that Megophias megophias and its vast repertoire of surface behavior couldn't adequately explain the range of reports and proposed nine sea serpent types. Mammalian sea serpents dominated with the long necked (giant pinniped), merhorse (pinniped? archaeocete?), super otter (very primitive archaeocete), many humped (Basilosaurus-like archaeocete), and many finned (very derived archaeocete). I discussed the last one at some length and was baffled at how Heuvelmans came to the conclusion that he did with the information that he had - for one thing most reports never mentioned the titular characteristic! Oh and there were also multiple giant eels and eel-shaped fish, a giant crocodile-shaped reptile, a giant turtle (dropped), and a tadpole shaped giant yellow bellied something (dropped), here's a charming little illustration of the whole bunch. I don't think that Heuvelmans started off with preconceptions but his text hints that he had a fairly concrete idea of the types early on. Coleman and Huyghe recently attempted to clean up the system by combining the long necked and merhorse (waterhorse), the super eel and super otter and many humped (classic sea serpent) and basically kept the rest (mystery saurian, cryptic chelonian, great sea centipede). The team's bigfoot classification was problematic, but this classification seems more conservative and plausible (except for the giant beaver, egads). Not too much was added by the team and it appears that all of the problems with Heuvelmans got passed on, like finless many finned sea serpents. It really is just about time for someone to start this all again from the ground up.

The first indication of another classification system was "A Preliminary Evaluation of a Study of the Morphology, Behavior, Autoecology, and Habitat of Large, Unidentified Marine Animals, based on Recorded Field Observations" by Bruce A. Champagne in an online collection of Cryptozoology articles called Dracontology. Coleman and Huyghe cited the article but didn't discuss it, perhaps due to its preliminary nature. Aside from some excerpts getting posted on Cryptozoology.com, nothing else was published or mentioned for around six years. Late last year in the book Elementum Bestia, Mr. Champagne published "A Classification System for Large, Unidentified Marine Animals based on the Examinations of Reported Observations". It does seem to be very interesting indeed. There are now 1247 reports on file with much more data getting taken into account, such as water temperature, salinity, current et cetera. Although not mentioned in the report, I think recording data that the witnesses couldn't have been subjective about is an interesting way to make the reports seem more plausible (assuming there were patterns). Unfortunately, documentation of the reports is not done in the article - some of them were apparently odd enough that I'd like a way to track them down for myself. Perhaps it was beyond the scope of the article. Not all the reports were used anyways, and there was an established point system (+1 for a qualified observer, +1 for physical evidence, etc) that whittled the number down to 209. Quantifying quality of reports is subjective of course, but at least it is attempting to be more scientific than past incarnations. In fact, both articles are written in a style reminiscent of technical peer-reviewed literature.

The author is very mysterious and searches for past articles on marine biology and cryptozoology online have proved fruitless. If anybody has any more information on him (or if he's reading this!) please, do share.

Time to discuss the sea serpents themselves, and yes, there are more than 9.


Type 1: "Long-necked"

These are reports that, of course, are of long necked animals. Confusingly, other types have this characteristic (3, 4B), but presumably other characters took precedence. This type is somewhat comparable to the long-necked/merhorse/super-otter classification of Heuvelmans and the "waterhorse" category of Coleman and Huyghe. Unlike previous authors, it has been divided into two sub-types.


Type 1A:

This "long necked" is primarily distinguished by a head of the same or slightly smaller diameter than the neck. Type 1As are reported worldwide, but appear most in boreal climate zones. They aren't even limited to salt water and have apparently been sighted several kilometers inland in fresh water, possibly to breed. Champagne also suggests that this type is a pinniped and a relatively large one at 2.5-12 (9 avg) meters in reported length. Given peoples' tendency to exaggerate, I'd suggest that this type could fall within the mass range of pinnipeds. The proposition of a long necked and tailed pinniped raises a lot of questions. Pinniped necks actually aren't longer than a dog's ('cept Acrophoca see Darren of course) and tend to be immensely thick to boot. Pinnipeds have very short tails, and the Coleman/Huyghe book suggested that reports of a long tail are due to the rear limbs. The superficial plesiosaur or elasmosaur-like body coupled with a pinniped-style flexible neck makes this type quite unique and would presumably indicate an unknown niche. The idea of a pinniped being fully adapted to a marine life and taking on a new form doesn't seem too outlandish, and at least this type resembles common sightings. The lack of resemblance to anything in the fossil record is still a major problem of course.

Type 1B:

This "type" is only known from 5 sightings in the North Atlantic and is distinguished by a head larger in diameter than the neck. It is supposedly much larger (17 meters+) than the 1A and displays more "primitive" characteristics and different behaviors (frequently associates with cetaceans, etc). Oh, these illustrations are ones that I did a while back, so you'll see I chose to portray it as a more robust "1A" type animal as opposed to another lineage of long-necked creature. Limbs were never observed and only inferred to exist by presumed relations. The proposed anatomy of this type is even stranger than the 1A, and I don't know what to think of a massive head on a long neck. Judging by the lack of sightings or apparently much detail, I'm suggesting that future analyses will probably just absorb these sightings into the "1A" or maybe "type 3" classification. Ah, to lump or to split, the eternal question.

Type 2: Eel-like

Animals described as just that, eel-like. Only about half of the reports were detailed enough to classify, and the three sub-types specified seem very divergent. The first two types have no analogy in Heuvelmans, and the last one (exemplified by the Daedalus sighting) is a bit super-eel or yellow belly-ish.

Type 2A:Although not outright mentioned, the reported details of this type match up the Tresco encounter, which Heuvelmans rejected due to its outlandish nature. Apparently there have been similar, more subdued sighting of a similar nature in the western Atlantic. Coleman and Huyghe noted that Mangiacopra once had a classification with an apparently similar sea serpent, but further information is lacking. This type is distinguished by a squarish head and scales. The head supposedly has pendulous lips, mucous emanating from the mouth, and either horns or tusks. The compliment of fins is confusing, it has variously noted as having a dorsal fin (once) as well as fan-like pectoral and/or anal (?!) fins. I portrayed it as a limbed sea snake-like animal with a very thick body (8-18% the total length). The reports average 6-9 meters with one 30 meter report (the Tresco). This type seems very...confused...and the idea of a reptilian walrus analogy off the Eastern coast of the US and Canada is quite a bit out there. I'd like to know the location of the other reports and how many there even were and if alternate explanations are possible (hoaxes?).

Type 2B:

A much, much more mundane and believable "sea serpent", this actually appears to be an unknown beaked whale of some sort distinguished (from other type 2s) by a pointed head. One report mentioned an ambiguous structure behind the head (a "mane"), but this animal is suggested (by the author, not in the article) to have a series of bumps on the spine instead. Once again, I'd be curious to have the reports available because it would be interesting to know if the witnesses simply observed a known species of large (7.5-9 m) beaked whale and didn't note the dorsal fin. The type 3 sea serpent supposedly has a mane and series of humps as well. Sightings were rather uncommon (once every 40 years) and it doesn't seem like this type has much merit. It was seen in both the Atlantic and Pacific and hasn't been reported in over 80 years. What a shame, an unknown beaked whale (even one with a series of humps replacing a dorsal fin) is a fairly plausible cryptid by anyone's standards.


Type 2C:
The last type of "eel-like" animal, this time distinguished by a blunt "cow-like" head. The head is reported as being quite large proportionally (14-33% of the total length), which seems a bit jarring with the Daedalus illustration. It is also described with a tapering tail (making it tadpole shaped?). This is also a proportionally rather thick (10-16% total length) and long (18-24 m) animal with a rigid body and no reported appendages. Like the Daedalus sighting, it just isn't too clear how this animal is propelling itself. This type has been observed in the Atlantic and Indian Oceans as well as the South China Sea. It hasn't been observed in 70 years either. The mouth was described as sub-terminal, hard to see when closed, but overall large and with sharp teeth so Champagne hypothesized that this was a zooplankton feeder. As for classification, he proposes that this is a reptilian animal, and I'm not too clear on why. Apparently this is an aggressive tail slapper like a lepidosaur, although where it derived from I don't have a clue. I portrayed it as a very massive sort of sea snake or sea snake-like reptile.


Type 3: Multiple-humped (available: Here and Here)

This is pretty much the sea serpent, it is responsible for about 1/3 of the sightings, is reported worldwide, and is synonymous with "Cadborosaurus" and others. Bruce wrote another article on the Clark brothers' video which he interpreted to be of this "type". It has been reported in areas from the open ocean to several kilometers inland in fresh water, and has been reported from estuaries with great frequency. Oh, and apparently it can venture over land. The anatomy of this type, despite it being so common, is absolutely baffling. The head is camel-like with a sub-terminal mouth, a spear-like tongue, prehensile lips, possible vomerine teeth, and maybe some sort of crest or a mane. The neck appears to be quite long (the foreflippers are located about 1/3 back) and the bilobate tail is plated and apparently capable of making sound. Oh yes, and apparently the body has yellow "spines" and it has been reported up to 60 meters in length (move over Amphicoelias!) with 10-20 meters average. If this reported animal actually does have all those variable characteristics, then I can't help but wonder if it is responsible for or confused for some of these other "types". The author doesn't specify the classification index, but appears to plump for a reptilian identity. I'd have no idea where this animal fits in classification-wise, presumably the only reptiles that could have adapted to vertical undulations would be archosaurs of some sort - even though crocodiles don't. The lack of evidence of anything remotely resembling this in the fossil record is a huge problem, but not outright disproof. Even if there are many good sightings and a weird carcass ("carcass"?), this type is still hugely unsettling.



Type 4: Sail finned
Another category of largely dissimilar animals sharing a vaguely similar feature. The first type has no analogy in the other systems, and the second (more common) type is somewhat comparable with the super eel and Valhalla sighting.

Type 4A: (Available: Here)
Yet another "sea serpent" that appears to be a sort of beaked whale. I feel that this drawing came out the best, by the way. This animal is also from the northwest Atlantic Ocean and was unfortunately last seen in 1912. How many sea serpent types live off the Eastern US coast anyways? Apparently "Paxton 1995" discusses this animal, although it wasn't listed in the works cited. Despite the "crocodile-like" head and "scales" (warts? barnacles?), this type does seem to resemble a cetacean. Once again, I'm curious about the actual sightings to confirm (for myself) that this actually does resemble a large (9-21 m?) ziphiid with an unusually small head and large dorsal fin. A recently extinct beaked whale isn't too unusual by anyone's standards, and I'm sure that marine biologists would find the reports interesting.


Type 4B: (Available: Here)
Another very strange proposed animal, the author considers this "a transitional animal with reptilian and mammalian characteristics". The closest thing to an aquatic non-mammalian synapsid appears to be the Ophiacodontids - however they're very very old and don't show any obvious aquatic adaptations. The neck is apparently long and there are no appendages, so the animal supposedly moves by ostraciform swimming with the large dorsal fin. At a reported 4-26 meters long, this would be by far the largest animal using that locomotion and I wonder how effective it would be at such sizes. The head is of similar diameter to the neck and has a large mouth, lips, and "tendrils". The overall body shape, disregarding the inferred neck, does strongly suggest a fish of some kind, somewhat reminiscent of Derichthys. I think it is likely that this type will be included within another "type" in future classification.


Type 5: Carapaced Animal

Yet another animal described as being a "reptile-like mammal, or transitional/intermediate animal of unknown class" regardless of the resemblance to a turtle. The measurements (thickness 75-90% total length, thickness 60-75 total length) give it a fineness ration of a little over 1 and proved impossible to portray plausible, so something must have been wrong (flippers included?). Aside from the plated, shell-like carapace and long (!) wedge-shaped tail, the animal is occasionally described with oily hair, quills (!), and a seal-like head, probably resulting in the bizarre classification. I think if reports were selected differently a much more plausible looking animal could result, although plausible looking doesn't necessarily mean more likely.


Type 6: Saurian (Available: Here)

An animal with a crocodilian (occasionally seal-like) head ranging from 1-20 m in length from the (sigh) North Atlantic and Mediterranean. The occasional spots are the only new piece of information to this Marine Saurian/Mystery Saurian animal. Reports seem rare enough that this type will probably just remain some sort of curiosity.


Type 7: (Available: Here)

I've talked about this animal far too much as it is. Apparently only 6 sightings were used, 3 of which are from carcasses (!) and one of which was photographed (!!!). That last bit of information should be major news, but there aren't any references to where it can be found. Even compared to the other improbable animals, this is a particularly troublesome one.


Type 8: Digited Animal (Available: Here)

This type of "sea serpent" appears to be based off of the Canvey Island Monster to some degree, which was probably some relative of the anglerfish (poorly reported). The idea of an aquatic chameleon-like reptile has been proposed before in the case of Hypuronector, although it is now thought to be arboreal like the rest of the bizarro Avicephalans. This "type" can probably discarded due to suspected misidentifications. This really goes to show the importance of at least referencing the sightings used.


Type 9: Snake-like (available: here)

A 6-18 meter long snake-like animal with a squared head and visible scales reported from the Atlantic. This seems very similar to the 2A sea serpent, although this wasn't mentioned. I made a preliminary drawing and sent it to Bruce, but he didn't give feedback and it didn't make it into his report.


Giant cephalopods were also mentioned but never discussed.


This does indeed seem to be a very interesting classification system. There are a lot of questions left to be answered, and I can't help but think that the scope of the article is somewhat responsible for that. I think a lot more discussion by the author would have been necessary rather than leaving it to the reader. There certainly does seem to be a lot of interesting information covered, and I think a better medium than a short (~30 page) article in a obscure book with no ISBN would be necessarily for the best airing. It still seems like a lot of people had not heard about this classification, hence me writing about it. Undoubtedly the story does not end here and somebody else in time will build on this and other system to make yet another one.

I don't know if we'll ever find a "sea serpent" in the ocean. Yes, yes, we're all aware how large and mysterious the oceans are, but an apparent unknown branch of aquatic, say, synapsids, stretches credibility past breaking point. I'd personally suggest that the most parsimonious explanation is that there is a single aberrant species which, combined with cultural preferences hoaxes and mundane phenomenon creates the sea serpent phenomenon. Well, that is assuming that there is an unknown species to begin with.


Well, I'm tired of Cryptozoology for now

-Cameron

The nearly eel-shaped dolphins

The story goes that Richard Ellis once referred to right-whale dolphin species (genus Lissodelphis) as being elongated to the point of nearly being eel-like. These sentiments have been shared by (repeated by?) other publications (e.g. Stewart et al., 2002) and strangely omitted by others. The species are occasionally depicted as being fairly normal shaped delphinids, but photographs confirm that yes, these are very elongated cetaceans.

Lissodelphis borealis, based off of Reeves et al. 2002 and Perrin, 1991. Until I get permission to use the image, this quick illustration will have to do. For those of you with access, I highly recommend looking at the Perrin picture. FR for this picture is about 8, it is around 10 for Perrin, 1991 but apparently reaches 11 (keep reading).

As the pictures indicates, the local nickname "snake porpoise" doesn't seem that far fetched. These are of course not porpoises but dolphins (delphinidae) in the subfamily Lissodelphininae. Two species are in the genus, a more elongated northern species (L. borealis) and a more massive southern one (L. peronii). Other genera in the subfamily, recently demonstrated to be monophyletic, include Cephalorhynchus and "Lagenorhynchus" (Harlin-Cognato & Honeycutt, 2006). None of the other species are elongated and all of them posses dorsal fins, although a few do have a similarly stark black and white coloration (C. commersonii, L. cruciger). The family Delphinidae appears to have originated around 16 million years ago (Arnason et al., 2004) and coupled with the lack of similarity with relatives and the lack of a fossil record (Newcomer et al., 1996) suggests that this body plan derived quite recently.

The southern right-whale dolphin (L. peronii) was first described in 1804 and is distinguished by its northern relative by a coloration pattern with more white, a greater girth, and proportionally larger flippers (Newcomer et al., 1996). The coloration for both species is variable: all black and all white individuals are known as well as L. borealis specimens with a similar coloration pattern (and "swirled" L. borealis). See this picture for typical coloration. L. peronii is a circumpolar animal that normally inhabits 35 to 62 degrees South (up to 12 degrees) while L. borealis (described 1848) inhabits the north Pacific between 35 and 51 degrees N. Both have been noted as being very common species, estimated to be in the tens of thousands (Jefferson & Newcomer, 1993 and Newcomer, et al., 1996). Both are fairly small cetaceans with L. borealis reaching 3.1 m and 113 kg and L. peronii reaching at least 2.97 m and 116 kg (it has fewer samples). Right-whale dolphins are gregarious creatures with groups occasionally numbering over 1000, although L. borealis has been seen singly and L. peronii is sometimes seen in small groups. Other species of cetaceans are often affiliated with these species, and one species of pinniped has been associated with L. borealis. Habitat-wise these are cold water species affiliated with the open ocean or deep water. There does not seem to be much indication for why such a unique body could evolve from looking at the current information on the ecology of the species.

Quite unexpectedly, L. peronii has been recorded swimming at 22 km/h and L. borealis at over 40 km/h. Presumably L. peronii can travel faster but has not been adequately measured. 40 km/h would make L. borealis one of the faster species of dolphins, and Fish 1996 noted that another species of very fast dolphin, Dall's porpoise (Phocoenoides dalli) had a very divergent body plan. Using a fineness ration (body length/maximum thickness) the body shape with the least amount of drag was calculated to be 4.5; Dall's porpoise had a value of 4 and L. borealis had a value of 11. A value that high seems quite extreme, and (since figures are not available) I wonder if it is approaching the FR for Basilosaurus. Since longer shapes produce more drag, how are these species some of the fastest dolphins? Fish notes the FR is of course not the only indicator of performance, and streamlining, such as a fusiform body, also plays a large role. The species are noted as being dorso-ventrally instead of laterally (Stewart et al., 2002), although I'm not sure how that would streamline the animal. It is unfortunately noted by most workers that many aspects of the biology of this genus is unknown (Rankin et al., 2007).

The story doesn't have to stop there. The only thing noted about the skeleton of L. borealis (and presumably L. peronii) is that all aspects of it are weakly built (Jefferson & Newcomer, 1993), that is prior to Buchholtz & Schur 2004. It is first noted that Lissodelphis has an abnormally high lumbar vertebrae count; typically in delphinids with high counts lumbar vertebrae are "capped" at 24 with additional caudal vertebrae added, but Lissodelphis may have more lumbars than caudals. Surprisingly their total count (86-89) isn't the highest, but is exceeded by Lagenorhynchus albirostris (91) and approached by other members of the genus (77+), which, er, may be polyphyletic (Harlin-Cognato & Honeycutt, 2006). Buchholtz & Schur suggest multiple origins for this trait, as Lissodelphis combines primitive traits (no reversal of vertebrae orientation or syncliny, low torso metapophyses, short neural spines) with derived ones (vertebral count, disk shaped ("discoidal") lumbar vertebrae, and a secondary rise in the torso). The authors treat the strange spinal characteristics as further anomalies, although the mention of a "leaping style of locomotion" should be significant. Jefferson & Newcomer 1993 and Newcomer et al. 1996 mention that both species make low angle leaps at high speed with a great amount of surface disturbance but don't point out that this is anomalous. Presumably the vertebral derivations are directly related to this behavior, but there are many aspects of this species that are still baffling.

The only other species of cetaceans completely lacking any sort of dorsal structure (fin or ridge) are the right and bowhead whales (Balaenidae), although they are not noted as being fast swimmers and there seems to be a tendency for polar cetaceans to reduce their dorsal structures. The caudal fins in at least L. borealis seem quite small as well, so these species must have some mechanism to stabilize. Clearly there is much to be learned about these species, and I'm sure those interested in underwater robots mimicking animals will find this species of interest.

So that's the story so far for this anomalous genus. One of these days we'll have a more complete picture of whatever odd mechanics are occurring, but probably never fully complete. I have the feeling that this elongation is not comparable to that of some archaeocetes, but we'll have to wait and see. It seems like there's always something left to be discovered and described about species, so unfortunately I can never write a truly complete post. Oh well.


I'm currently waiting for something to ship to me and when it does, expect a post of monstrous proportions...

-Cameron



References:

Arnason, Ulfer et al. 2004. Mitogenomic analyses provide new insights into cetacean origin and evolution. Gene vol. 333.

Buchholtz, Emily A. & Schur, Stephanie A. 2004. Vertebral osteology in Delphinidae (Cetacea). Zoological Journal of the Linnean Society, 140, 383–401.

Harlin-Cognato, April D. and Honeycutt, Rodney L. 2006. Multi-locus phylogeny of dolphins in the subfamily Lissodelphininae: character synergy improves phylogenetic resolution. BMC Evolutionary Biology 6:87.

Fish, Frank E. 1996. Transitions from Drag-based to Lift-based Propulsion in Mammalian Swimming. Amer. Zool. 36:628-641.

Jefferson, Thomas A. & Newcomer, Michael W. 1993. Lissodelphis borealis. Mammalian Species. No. 425, p. 1-6.

Newcomer, Michael W. et al. 1996. Lissodelphis peronii. Mammalian Species. No. 531 p. 1-5.

Perrin, William F. 1991. Why are there so many kinds of whales and dolphins? BioScience vol. 41 n. 7, 460-461.

Rankin, Shannon et al. 2007. Patterned burst-pulse vocalizations of the northern right whale dolphin, Lissodelphis borealis. J. Acoust. Soc. Am. 121
(2), p. 1213-1218.

Stewart, Brent S. et al. National Audubon Society Guide to Marine Mammals of the World. Knopf, 2002.

New World Old World Vultures?

Quite a while ago I discussed the fossil history (and perhaps origin) of the cathartids or "New World" vultures in the Old World - and hinted at a "tale for another day". The cathartids are of rather uncertain taxonomic placement (a distinct order?) while the "Old World" vultures are placed in order Falconiformes* in the family Accipitridae and sub-family Aegypiinae. BUT - and there always is one regarding classification these days - this should be "Aegypiinae" since genetic evidence suggests that Gypaetus (Bearded vulture), Neophron (Egyptian vulture), Gypohierax (Palm-nut vulture) and perhaps Polyboroides (Harrier-Hawks) form a clade rather distanced from the remaining 6 genera of "vultures" (Griffiths et al., 2007). So Aegypiinae is apparently both para- and polyphyletic, huh. As the photos suggested, the three genera of "vultures" are superficially rather aberrant looking so perhaps this is not too much of a shock. Siebold & Helbig 1995 suggested the sub-family Gypaetinae for Gypaetus and Neophron; and I'll use Aegypiinae for the remaining and more conventional "vultures".

*Or Accipitriformes, Griffiths et al. 2007 placed Falco pretty far away. I probably shouldn't get into this.


Why go through all this trouble? Reportedly, both Gypaetinae and Aegypiinae have occupied the New World at some point of time. This is rather remarkable on top of the vulturids/cathartids living there and caracaras (Polyborinae). Marabou stork relatives (Leptophilini) were also present, but there's nothing to suggest they were scavengers (Jabiru isn't). Oh and teratorns don't appear to have been scavengers, despite their common depiction as super-condors.

Anyways, let's take a look at these New World Old World vultures:


Gypaetinae

Neophrontops is a genus with five species related to Neophron that lived in North America from the mid-Miocene to upper Pleistocene (Fedducia, 1974), so it certainly did not have a very casual appearance. I should note that Fedducia's described species, Neophrontops slaughteri, was named for, ehem, one Bob Slaughter. Fedducia's vulture species did not appear to overlap chronologically but a later study (Rich, 1977) showed that two species (N. americanus and N. vallecitoensis) were both present in the mid-Pleistocene with different sizes (the latter was larger); this could make it a radiation of sorts, albeit a rather brief one. Fedducia notes that Neophron fossils have not been found in Africa (this still appears to be true) and suggests that, gulp, the current species is the result of an invasion of Old World vultures to the Old World from the New World perhaps as recently as the Pleistocene. The genetic grouping with Old World species may not be entirely inconsistent, although it would require this lineage to be oddly invasion prone.


Aegypiinae?

While the Neophron/Neophrontops relation appears to be rather unambiguous one, larger reported New World Old World vultures are rather, well, problematic. Two genera have been classified in Aegypiinae: Palaeoborus and Neogyps. In the description of a new Palaeoborus species by Miller & Compton 1939, it (well, its ulna) is noted as being similar to Neogyps except for differences in the shape of the condyle; oh and it is somewhat comparable to Haliaeetus. Why does this stick out to me? Hertel 1995 notes that Neogyps, the "Errant eagle" was originally considered an eagle with vulturine habits, then re-classified in Aegypiinae; but skull indices used to determine diet classified it as a mammalivore, possibly a generalized one. I unfortunately couldn't find Patricia Rich's book on the subject of fossil vultures, but the book The Origin and Evolution of Birds* by Alan Fedducia (partially available here, p. 299-300) notes that she couldn't conclude on their relations and raised the possibility that they are one or more separate branches of hawks or eagles.

*Oh, and it mentions that Ciconia maltha was the ecological equivalent of the marabou stork. I haven't seen this confirmed elsewhere.


I haven't seen any more recent work on the phylogenetics of these species, although that would be difficult seeing as how Accipitridae is currently undergoing upheavals. Are the genera related? Palaeoborus is from the Upper Miocene to Lower Pliocene and Neogyps is from the Upper Pleistocene (Fedducia, 1974), so there is only a mild ghost lineage. Fedducia hinted at the possibility of Old World vultures having New World origins, but we'd have to assume that eagle-like characteristics were due to the basal nature of the genera. These seem to be rather ambiguous species here, so it doesn't seem as if we can do much aside from speculating on their relations. I guess for now that we'll have to conclude that there is no unambiguous evidence for New World members of Aegypiinae.


Not having Rich's book has made this post difficult, but it appears that nothing more definitive can be known. I for one thought things were a little more definitive before starting this post for one thing, but I learned better. Well, at least we got New World Old World "vultures" of a sort.

Next time I think I'll blog on something less old and ambiguous.

-Cameron

References:

Fedducia, Alan. 1974. Another Old World Vulture from the New World. The Wilson Bulletin. Vol. 83, No. 3. Available (for free).

Griffiths, Carole S. et al. 2007. Phylogeny, diversity, and classification of the Accipitridae based on DNA sequences of the RAG-1 exon. J. Avian Biol. 38: 587- 602.

Hertel, Fritz. 1995. Ecomorphological Indicators of Feeding Behavior in Recent and Fossil Raptors. The Auk, Vol. 112, No. 4., pp. 890-903.

Miller, Alden H. & Compton, Lawrence V. 1939. Two Fossil Birds from the Lower Miocene of South Dakota. The Condor, Vol. 41, No. 4., pp. 153-156.

Siebold, Ingrid & Helbig, Andreas. 1995. Philosophical Transactions : Biological Sciences, Vol. 350, No. 1332, pp. 163-178

Rich, Patricia Vickers. 1977. Temporal range extension of Neophrontops americanus (Accipitridae). The Condor, 79: 494-509. Available (for free)

Four Finned Cephalopods

On this old post, I mentioned the factoid that the vampire squid has four fins at one developmental stage. Vampire squids (Vampyroteuthis infernalis), as mentioned at this other old post, are a distinct group of cephalopods usually connected with octopodes - although this may not be the case. And yes, continuing with the recent trend this is the sole species of an entire order (superorder?) which may have originated as early as the Devonian.

Despite the very strange morphological feature of another pair of fins (briefly), I've seen no discussion of it and assumed it was some bizarre slip of the pen until I saw the picture I linked to earlier. Considering that all other cephalopods have either one pair of fins or none, this occurrence really should have raised eyebrows. Mercifully, the article by Donovan et al. (available on the Internet Archive) not only appears to be the first discussion of this oddity, but demonstrated that the vampire squid is not an isolated case.

For one thing, the Chiroteuthid Grimalditeuthis also possesses 2 pairs of fins as an adult and Chiroteuthis does in juvenile forms (Donovan et al 2003), although if you note from the links the secondary pair of fins are referred to as "fin-like flotation devices" and the larvae of Chiroteuthis are, well, extremely bizarre with siphonophore imitating growths which appear to be retained. Since this is not present in any other species of Chiroteuthid or decapodiform, we can fairly confidently say these are not homologous structures. It would be interesting to if the "fins" are modified portions of existing fins or non-homologous structures - or both maybe. But this is aside from the point.

Trachyteuthis is a fossil coleoid from the Upper Jurassic which was first described in 1896 (known since at least 1829) and subsequently reconstructed something like this. Other specimens hinted at the possibility of two pairs of fins; the specimen described by Donovan et al. made it clear that the species did posses them. The specimen was at the upper size limit for the species (~380 mm gladius length), so there is no question that this is an adult specimen. The animal was preserved showing the dorsal surface with the four fins present; they each appear have a base and the proximal pair has thicker muscle bundles. The fins appear to be directly attached to the gladius, although it is not clear if by a fin root pocket or directly by cartilage. Trachyteuthis, apparently had a well-muscled mantle and could presumed capable of jet propulsion, so these fins were likely used for stability or control of altitude rather than propulsion (Donovan et al 2003), like cirrate octopuses. The potential mechanics of why two pairs were needed was not discussed, although since Vampyroteuthis re-absorbs its extra fins presumably they don't offer that much of an advantage (for its lifestyle). Here's the obligatory link on many-finned fishes, which demonstrates that extra fins may sometimes have advantages.

So what exactly is Trachyteuthis? There is a noted resemblance between the three-part gladius of this species and Vampyroteuthis (plus Mesoteuthoidea and Prototeuthoidea), although Vampyroteuthis resembles Loligosepia much more, suggesting Trachyteuthis is a sort of side branch. The arm crown is a more definitive way of determining cephalopod identity; while fossil Trachyteuthis have left the impression of eight arms, it is possible for two more arms/tentacles/filaments to have been present and not preserved. The authors conclude that the four fin condition may have been primitive in Octobranchia, and it cannot be determined if all coleoids once possessed this feature (Donovan et al., 2003).

So there we go, we went from a factoid occasionally mentioned in books and websites to a potentially very old feature. Since vampyromorpha appears to be a very old lineage, I don't find the suggestion that all octopodes also started off with four fins. Would the extra fins be detectable in their embryos (do incirrates absorb fins?) as it is in juvenile vampire squid? I should mention that Pohlsepia was an incredibly old (~300 mya) "octopus" with eight arms, two fins, and no shell; although that last feature suggests it wasn't an ancestor of cirrates/incirrate octopodes which presumably split in the Jurassic from an ancestor with an internal shell. If the shell was mis-interpreted as something else and it was an octopod-ancestor maybe four fins wasn't an ancestral characteristic for octopodes, or vanished quickly. The lack of soft bodies preserved and the apparent fact the the gladii of fossil cephalopods tend to convergently evolve (Donovan et al., 2003) would seem to make fossil cephalopods a taxonomic nightmare. It could be possible that Trachyteuthis was an unrelated cephalopod that also possessed a feature one of Vampyroteuthis' ancestors evolved (and somewhat lost), but that coupled with gladius similarities does suggest a connection, albeit a rather tenuous one.


Ah, I like not having to look up a couple dozen articles. I've got a handful of post ideas at once here (most lengthy), so let's see what happens. Probably no more fossil cephalopods, yeesh.



Reference:


Donovan et al. 2003. Two pairs of fins in the late Jurassic Coeleoid Trachyteuthis from Southern Germany. Berliner Paläobiol. Abh. 03, p. 091-099. Available

Attempted re-re-reconstruction of Trachyteuthis. I chose to portray this as a pelagic Vampyromorphan - characteristics of this group include a broad gladius extending the full length of the mantle (~380 mm) and no clear head/mantle differentiation. Earlier reconstructions showed the latter feature, although that appears to be speculative. The body is reconstructed as being bullet-shaped like a pelagic squid (e.g. Loligo) assuming the fossils were somewhat flattened; the impressions support the idea of large eyes. I chose to portray it with 8 appendages (filaments hidden or lost) with a single row of suckers (ancestral to vampire squids and octopodes?) and no cirri (a deep water adaption?). An ink sac and chromatophores are probably not present, unless it converged upon decapodiformes. I'd suggest that one pair of fins could be held in a plat plane and the other somewhat upwards, perhaps in an analogy to the pectoral/pelvic fins of fishes or the wings of Microraptor; they are <70 mm long.

More Anguilliform than Anguillidae

As I realized with the pig-nosed turtles, writing on just one species can be very difficult. I'm still not entirely sure how some people can write far-reaching articles summarizing entire groups, my hat goes off to them. Despite spending an entire semester coping with writing papers on the death penalty, juggling 20 articles or more at once still ain't easy, even on vacation. I don't want to spend another week on a post like I did the last one, yeesh.

Well, enough complaining. As you could tell from my previous post I clearly had "primitive fishes" on the mind, in addition to turtles, particularly lampreys and hagfish. Discovering that I do indeed have access to the book Primitive Fishes outside of Maine made writing a post on them inevitable. Note the title for a hint at where this is leading.

While the pig-nosed turtle was a relict that could shed light on early cryptodire or possibly chelonian evolution, hagfish (Myxiniformes) and lampreys (Petromyzontiformes) branched off somewhere close to the origin of vertebrates themselves. While they share features such as pouch-like gills, a lack of jaws, horny "teeth", and a protractible/retractable "tongue"; hagfish lack vertebrae and display many "invertebrate" characteristics. Genetic and morphological evidence still hasn't determined if lampreys and hagfish form a monophyletic group ("cyclostomes") or not; if they do then either hagfish have many reverted characteristics or lampreys have converged significantly upon jawed fishes (Janvier p. 13). The concept of lampreys being the sister grouped to jawed vertebrates and hagfish being non-vertebrates seems to be the most common, and in my opinion the best supported. Hagfish and lampreys have apparently retained highly derived characteristics for at least 305 and 360 million years respectively (Janvier p. 6-7) and presumably these adaptations allowed them to survived for as long as they have. I don't really prefer the term "primitive" because it conveys that there is something inadequate about the creature, but evolution works by the concept of "if it ain't broken, don't fix it?" Hagfish are capable of incredibly slime production, which suffocates fish gills (indicating that they can tolerate no oxygen for extended periods), and their flexible spine allows them to tie themselves in knots to clean off mucous or make it hard for predators to handle (Ilves & Randall p. 523). At least one species of lamprey is capable of surviving out of water in humidified are for at least four days while maintaining the same metabolic rate, and they are very capable swimmers (Brauner & Berenbrink p. 229).

This brings us, eventually, to the what inspired this post. From the "Locomotion in Primitive Fishes" chapter it is noted that eels (Anguillidae) move with anguilliform locomotion which involves bending a large portion of a uniform body; but lampreys and hagfish exhibit a lot of rostral movement which eels lack, and and arguably have a more characteristic anguilliform locomotion than the eels themselves (McKenzie et al., p. 322-323). Despite lots of research on the neurology of lampreys, the swimming method has not been very well studied. At low speeds in hagfish, tail beat frequency decreases with increased speed (possibly due to the notochord stiffness) although at a point speed increases with beat frequency. The authors suggest that "The recent work on hagfish suggests that there are likely to be interesting and fundamental principles of swimming that have yet to be described in these unusual fishes". That's an absolutely remarkable statement, although given the fishes in question perhaps it is not that surprising. Lamprey and Hagfish have encountered numerous radiations of animals throughout hundreds of millions of years with no major structural changes, so it is likely that there are many fundamental differences between them and conventional fish.

Exactly what advantages this form of locomotion has cannot be answered, but perhaps this locomotion is the ancestral condition for craniates/vertebrates which these two groups subsequently modified.

While not the exact same form of locomotion, tadpoles are also noted as wobbling their heads as they swim, which has been noted as poor swimming, and even used as a model for an inefficiently swimming vertebrate (Azizi et al., 2007). One early authority even declared that ‘‘the locomotion of the oldest vertebrates must have been of the relatively ineffective and uncontrolled type seen in a frog tadpole’’. However, oscillations of the head actually do appear to contribute to thrust, and a model of a tadpole without the "wobbliness" was less efficient. The vertebral column of tadpoles is very short (Azizi et. al, 2007), so it isn't too clear how comparable this could be to primitive fishes. Still, this and the remarkable swimming performance of lampreys suggests that "primitive" or "inefficient" locomotion can have some hidden surprises.

Since this article also somewhat functioned as an introduction to "cyclostomes", it looks like I'll have to make a few more posts...

Oh, and with the tadpoles, I should mention that this is the Year of the Frog.


References:

Azizi, Emanuel et al. 2007. Vertebral function during tadpole locomotion. Zoology 110, 290–297.

Brauner, C. J. & Berenbrink, M. "Gas Transport and Exchange" from Fish Physiology pages 213-283.

Ilves, K. L. & Randall, D. J.. "Why Have Primitive Fishes Survived" from Fish Physiology pages 515-537.

Janvier, Philippe. "Living Primitive Fishes and Fishes from Deep Time" from Fish Physiology pages 1-51.

McKenzie, D. J. et al. "Locomotion in Primitive Fishes" from Fish Physiology pages 319-380.

The Pig-Nosed Turtle

It seems like I have a soft spot in my heart for weirdo relicts. As I recall, one of the highlights of my previous semester was finding the book Primitive Fishes which discussed why fish like bowfin, gar, sturgeon and "fish" like lamprey and hagfish still linger on. It never ceases to fascinate me how an entire radiation can be reduced to a few species. I'll have to wait for those guys when I feel like talking about fish, but today I will discuss a group related to the softshell turtles, the Carettochelyidae.

This family of turtle has a single living species Carettochelys insculpta, the pig-nosed turtle of New Guinea and Northern Australia. It was described from the late 19th century as a New Guinea species (hence the alternate name Fly River turtle) and it wasn't known to have a breeding population in Australia until the 1970's (Georges & Kennett 1989). The species does not have epidermal scutes like most turtles; coupled with the fleshy snout and leather carapace and plastron it resembles members of Trionychidae, the softshell turtles. The limbs are paddle-like with two claws, and the species has been called the species of freshwater turtle most suited to an aquatic environment. I have not seen studies on the shell/plastron of this species, the reason why it evolved, and what advantages having such a shell would be; Trionychid shells offer many apparent advantages (lightweight, bendable, strong, able to absorb oxygen) although the pig-nosed turtle and extinct relatives do not have the same integumentary adaptations (Scheyer et al., 2007). It takes water in through the mouth and up through the nostrils, which may serve a respiratory function (Georges & Kennett 1989); I haven't seen any figures for how frequently it needs to surface, so the efficiency of this isn't clear. Carettochelys is apparently capable of living in salt water as well as rivers (Friar, 1985), although I have not seen any information if specimens do indeed move from New Guinea to Australia or if it posses adaptations to live long term in such an environment.

The distribution itself is unusual, since Carettochelys is the only freshwater non-pleurodire (side-necked turtle) in Australia (G. & K.), although one early authority considered it to be a pleurodire that convergently evolved upon Trionychidae (Friar, 1985). This apparently wasn't based upon biogeography and I'm baffled why the neck anatomy wasn't a dead giveaway. Due to the presence of flippers and a form of locomotion in between a freshwater and marine turtle (Friar, 1985) as well as the superficial similarity to Trionychidae, pig-nosed turtles were once considered to be transitional between marine and softshell turtles (Friar, 1983). Superficiality aside, Carettochelys is now strongly linked to the family Trionychidae forming the clade Trionychia, grouping with extinct forms in Trionychoidae, which in turn groups with the families Dermatemydidae and Kinosternidae to form Trionychoidea (Meylan et al., 2000). In a predictably unpredictable sort of way recent genetic evidence suggests that Trionychoidea is an invalid group, and that Trionychoidae is a distinctive lineage that split off very early from other turtle (Krenz et al 2005). Previous molecular clocks calculated pleurodires and cryptodires to have diverged 176 and 175 million years ago respectively with Trionychoidae branching off 155 million years ago, supporting one model of them being basal cryptodires. However, another possible model in Krenz et al 2005 suggests that Trionychoidae is a paraphyletic group encompassing the first two major divisions in the turtle lineage! If Carettochelys is the most basal turtle known that would be astounding (and the early worker was right about a pleurodire connection), though I think the previous model was much more probable. Genetic evidence seems to be undergoing a lot of flux, so I think it will be safe to wait before making any bold conclusions (which the authors didn't).

Figure 4 from Krenz et al 2005.

A photo marked "public" from Flickr. Note that the flippers are wider than those of sea turtles and have two prominent claws.

Regardless of whether or not this species occupies a very interesting position in the turtle family tree, its fossil relatives should be of species interest, well, to me at least. How does a group of animals wind up having only one species left and what caused it to survive? The group has been known since the Cretaceous in Asia, where it spread to Africa, Europe and North America post-KT only to wind up going extinct (Joyce et al., 2004). As of 1988 there appear to have been 6 genera of the family (18 were reported, many were unrelated or synonymous) (Meylan, 1988) in two subfamilies: Anosteirinae and Carettochelyinae. Anosteirine Carettochelyids are distinguished by the presence of marginal scutes which Carettochelyine Carettochelyids lost, apparently independently from Trionychidae (Joyce et al., 2004); other distinguishing characteristics include a small size (25-38 cm carapace length), one or more spines on the dorsal keel, and modified vertebral scutes and xiphiplastra (fourth lateral plate on the plastron) (Meylan, 1988). Large size is apparently a plesiomorphy in trionychoids which Carettochelyines retained - Carettochelys has a 55 cm+ carapace (Georges & Kennett, 1989), and Burmemys had one over 1 m (Hutchinson et al, 2004). Relict fish also tend to be rather large, although I can't be sure if size offers the same advantages to Carettochelys, if any. It is noted that this group is highly adapted to riverine environments (Joyce et al., 2004), and it is possible this is why (perhaps coupled with omnivory and large size) they survived the KT extinction and continued to straggle on like choristoderes.

Actually, it is somewhat puzzling now why this species has such a limited range. Georges & Kennett 1989 noted that it is a very broad omnivore, leaning towards herbivory, and it has been known to consume fruits, leaves, aquatic insects, fungi, and mammals such as flying foxes (presumably scavenged). It can of course survive a wide range of habitats include saline ones and its relatives have been known to inhabit temperate zones, so the authors suspecting it had to do with seasonal movements or the requirements of young individuals. Regardless of some areas with high densities it is considered a rare species (that term being hard to define), and it occupies home ranges much larger than those of other aquatic turtles: 36 hectares or 7.6 km linearly, much more than turtles of comparable sizes (Doody et al., 2002).

So here we have it, a remarkable relict species which may have survived due to its size and freshwater habitat and now appears to be somewhat constrained by it. Despite the late discovery and apparent rarity, this species does seem to be very well-studied; I've covered about half of the articles I've come across, many of which were from this decade. There certainly is a lot more to learn about this vulnerable species for those interested.

Is this what most American kids do on their 21st birthday anyways? Sigh...



References:

Doody, J. S. et al. 2002. Sex Differences in Activity and Movements in the Pig-Nosed Turtle, Carettochelys insculpta, in the Wet-Dry Tropics of Australia. Copeia, pp. 93–103

Friar, Wayne. 1983. Serological Survey of Softshells with Other Turtles. Journal of Herpetology, Vol. 17, No. 1., pp. 75-79.

Friar, Wayne. 1985. The Enigmatic Plateless River Turtle, Carettochelys, in Serological Survey. Journal of Herpetology, Vol. 19, No. 4., pp. 515-523.

Georges, Arthur and Kennett, Rodney. 1989. Dry-season Distribution and Ecology of Carettochelys insculpta (Chelonia : Carettochelydidae) in Kakadu National Park, Northern Australia. Aust. Wildl. Res., 16, 323-35.

Joyce, Walter G. et al. 2004. Carettochelyine Turtle from the Neogene of Europe. Copeia, Vol. 2004, No. 2., pp. 406-411.

Krenz, James G. et al. 2005. Molecular phylogenetics and evolution of turtles. Molecular Phylogenetics and Evolution 37, 178–191.

Meylan, Peter A. 1988. Peltochelys dollo and the relationships among the genera of the Carettochelyidae (Testudines: Reptilia). Herpetologica, 44(4), 440-450

Meylan, Peter A. et al. 2000. Sandownia harrisi, a highly derived Trionychoid turtle (Testudines: Cryptodira) from the early Cretaceous of the Isle of Wight, England. Journal of Vertebrate Paleontology 20(3):522–532.

Scheyer, Torsten M. et al. A plywood structure in the shell of fossil and living soft-shelled turtles (Trionychidae) and its evolutionary implications. Organisms, Diversity & Evolution 7, 36–144