As for where LeBlond and Bousfield's conception of 'Cadborosaurus' came from in the first place, it appears to be almost entirely based on the Naden Harbour carcass:
This... thing... has yet to be seriously analyzed and I am not convinced some of the purported features (eyes, lips, nostrils, armored tail) are unambiguously present and not just a trick of the lighting. Just because it can't be identified does not necessarily make it a cryptid.
Not only are the traits assigned to 'Cadborosaurus' a house of cards, they barely resemble those given to the Hagelund specimen:
There are indeed many points of similarity between the puny animal of Figure 31, sketched by Hagelund, and the adult Caddy: the long, thin shape, the large eyes, the teeth, the short front flippers. The scaly back is suggestive of the serrations mentioned by Langley and Kemp. Upon later questioning, Captain Hagelund also confirmed his impression that the tail region of the small animal was formed by two overlapping seal-like flippers, and not a single tail fluke. He also mentioned that he had noticed the flippers separating briefly while the animal was swimming in the bucket on the deck of his boat.This is seriously weak reasoning. While both are described as "snake-like", 'Cadborosaurus' was illustrated as being much longer and thinner than the Hagelund specimen and was classified as being proportionally dissimilar. LeBlond and Bousfield classified the eyes of 'Cadborosaurus' as being "sometimes large", and hence they were penalized for occasional presence. The presence of "flippers" would be interesting, although Hagelund's account is ambiguous as to whether they were fin-like or limb-like. The similarity of the tails are ambiguous since LeBlond and Bousfield gave a bizarre and somewhat contradictory description: they appear to interpret the Naden Harbour carcass as having a fluke-like structure made out of pelvic appendages, however the "striking features" note that "posterior flippers absent or nearly fused with the body" and the tail is "split horizontally or fluke-like at the top" - "fluke-like" and "seal-like flippers" are vaguely similar at best. Considering the "scaly back" and "serrations" to be similar is a huge stretch as Hagelund's drawing has a fairly smooth back and the "plate scales" sticking out could be due to the haphazard style of illustration. The comparison with the Langley encounter is strange since it was described with "serrated markings along the top and sides" and Kent's description noted that "[t]oward the tail it appeared serrated like the cutting edge of a saw", which is certainly not the case with Hagelund's illustration. What LeBlond and Bousfield don't mention about Kemp's illustration (see below) is that its mane has a crest-like appearance and an apparent crest in the middle of the body may or may not also be formed by hair:
|The original has a much smoother back... whoops.|
|Kemp's 'Cadborosaurus' is the huge dark thing in the middle with three distinct "crests". The Hagelund specimen is the lower-most (and tiny) creature and LeBlond and Bousfield's 'Cadborosaurus' is just above it.|
There were a few points of unambiguous similarity between the Hagelund specimen and 'Cadborosaurus' that LeBlond and Bousfield did not mention; a "head held out of the water" was not directly mentioned but implied by the observations of long necks and heads, and a "long snout" was synonymized with the often horsey head. Similarly, the "undulatory movement" of the Hagelund specimen was implied to be lateral, but since it wasn't directly stated, it was chalked up as similar. This is probably way too lenient.
More and better candidates will follow, but first, what are the implications of losing the Hagelund specimen from the 'Cadborosaurus' data set?
A Baby Cadborosaur No More. Part 4: What is 'Cadborosaurus'?
Tet Zoo Coverage:
A baby sea-serpent no more: reinterpreting Hagelund’s juvenile Cadborosaurus
LeBlond, P. H. & Bousfield, E. L. (1995). Cadborosaurus: Survivor from the Deep. Victoria, British Columbia: Horsdal & Schubart.