Tuesday, September 20, 2011

A Baby Cadborosaur No More. Part 3: Dealing With Traits

William A. Hagelund's specimen was given a very detailed description with 24 traits: an eel-like (or sea snake-like) appearance, head held out of the water while swimming, undulatory movement, dark eyes, limpid eyes, large eyes, seal-like face, slender head, slightly hooked snout, long snout, length of 16 inches (40 cm), diameter of 1 to 1.5 inches (2.5–3.8 cm), tiny teeth in both jaws, plate-like scales on the back, undersides with a soft yellow fuzz, flipper-like feet near the shoulder, spade-shaped tail, tail composed of two overlapping flipper-like fins, lips, whiskers, coloration of black on top and brown on the sides, yellow tail, and a head length of 3 inches (7.6 cm). Woodley et al. (2011) considered that the "ragged ends" of the tail in the illustration probably represent damage and not an actual trait. As many of the candidates in Woodley et al. (2011) are fish, the traits of dorsal fin(s), pelvic fins, and an anal fin were added. Due to LeBlond and Bousfield's claim that the Hagelund specimen represented a 'Cadborosaurus', "striking" traits absent in the former were added: ears and/or horns, tail dorsally toothed or spiky, and a long neck.

For almost all of these traits, their precise meanings and applicability to the candidates is subjective. A formula was devised where traits could be awarded partial credit... which I'll explain further on when dealing with individual candidates.

Perhaps the least ambiguous trait is "tail dorsally toothed or spiky", which only applies to LeBlond and Bousfield's 'Cadborosaurus'. Another 'Cadborosaurus' trait is the presence of "ears and/or horns", which can be reasonably defined as anything projecting out of the dorsal or lateral surfaces of the head. I don't think there is a universal definition of a "long neck", so we decided that since LeBlond and Bousfield's illustration of 'Cadborosaurus' shows a neck about twice the length of the head, that would serve as our definition.

Descriptions of colors can be culturally subjective, but this shouldn't a problem with two Englishmen and an American analyzing the account of a Canadian. Thus, the traits "black on the top and brown on the sides" and "yellow tail" can be treated fairly literally. Hagelund's description of "dark eyes" was problematic since the illustration doesn't provide any clues as to how dark they were; candidates with black eyes or eyes that are darker than the surrounding body were given credit. There was no way to define "limpid eyes" (i.e. clear) in a way which would give comparative value, however, it was kept due to the Finn John report's oddly similar usage.

The presence or absence of fins (dorsal(s), pelvics, anal) would seem like a simple matter, but it is complicated by the fact that some fins can be folded, transparent, or small enough to be easily overlooked. The "flipper-like feet near the shoulder" were synonymized with any sort of pectoral appendage, as the illustration confusingly showed fins-rays while the description implied something more limb-like. The "tail composed of two overlapping flipper-like fins" was treated literally (with pinnipeds getting full credit), although partial credit was given to fish with forked tails which could potentially fold and resemble the illustrated morphology. Hagelund's description of the tail as "spade-shaped tail" is, frankly, baffling in conjuction with the prior description, the illustrated morphology, and the fact that he (and nobody else, apparently) described the Sperm Whale's tail as such; the trait wasn't thrown out because the Finn John report interestingly used the same wording.

In the prior article, I wondered if "eel-like" was an appropriate description as the illustrated morphology and given measurements suggest it would barely qualify. Eel-like animals were given full credit, although others which are described as "elongated" were given justifiable partial credit. The measurements of body diameter and head length were modified into proportions relative to the total length, further controlling for Hagelund's dubious description. The "undulatory" locomotion was interpreted as anguilliform (having been compared to snakes and eels), however, I honestly have difficulty picturing the illustrated animal swimming in that manner and some partial credit was awarded to elongated fish which weren't quite anguilliform swimmers. As Hagelund didn't specify a plane, "undulatory" was awarded to swimmers in either plane (although lateral is implied).




The trait of the "head held out of the water while swimming" was hard to test for, but was given to obligate air-breathing candidates which would likely engage in the behavior. The possibility of a fish engaging in surface behavior is of course not impossible, although anomalous.

Hagelund's illustration was useful for determining the threshold of several traits: "large eyes", "long snout", and "slightly hooked snout". The portrayed depth of the head was used to determine a "slender head", although the possibility that Hagelund was referring solely to width should be raised. It was decided to not treat "tiny teeth in both jaws" with a similar threshold as Hagelund may have been drawing as small as he could (i.e., the teeth could have been much smaller than portrayed) and just testing for the presence or absence of teeth was deemed to be significant. The trait was simplified to "teeth" since no Sperm Whales or Beaked Whales were candidates and we didn't have to worry about teeth being present in only one jaw.

"Whiskers" was broadened to include barbels, and the location wasn't specified since the origin of the Hagelund specimen's "whiskers" aren't clear.

Hagelund unfortunately did not illustrate lips, so anything that would be described as possessing lips was given credit (i.e. all but the reptilian candidates).

The "plate-like scales on the back" were synonymized with the possession of any plate-like scales (scutes), as the illustration seems to imply that they covered much more of the body than the back. Precisely how much of the body the "soft yellow fuzz" covered was ambiguous (what, if anything, was between that and the plate-like scales?) and none of the candidates were given full credit. Candidates which are fully hairy and those with ventral structures which could possibly be interpreted as "fuzz" were given partial credit.

The meaning of a "seal-like face" is not at all clear, and it may be a reference to how the "dark eyes" made the face appear. It also implies that the eyes were visible from the front, however, this applies to most fish, yes even pipefish and sturgeon, so the comparative value of the speculative trait would be very limited. The only candidates which can justifiably said to have this trait are... pinnipeds.


Previous entries:


Tet Zoo Coverage: 
A baby sea-serpent no more: reinterpreting Hagelund’s juvenile Cadborosaurus




References:

Hagelund, W. A. (1987). Whalers No More. Vancouver: Harbour Publishing.

LeBlond, P. H. & Bousfield, E. L. (1995). Cadborosaurus, Survivor from the Deep. Victoria, British Columbia: Horsdal & Schubart.

Woodley, M. A., Naish, D. & McCormick, C. A. (2011). A Baby Sea-Serpent No More: Reinterpreting Hagelund's Juvenile "Cadborosaur" Report. Journal of Scientific Exploration 25(3), 495-512.

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