Rebuttal of Zuiyo Maru Carcass from "Lake Monsters" Facebook Page:
Sea-monster or Shark?
A decayed carcass accidentally netted by a Japanese trawler near New Zealand in 1977 has often been claimed by creationists and others to be a likely plesiosaur or prehistoric "sea-monster." Plesiosaurs were a group of long-necked, predatory marine reptiles with four paddle-like limbs, thought to have gone extinct with the dinosaurs about 65 million years ago. However, several lines of evidence, including lab results from tissue samples taken from the carcass before it was discarded, strongly point to the specimen being a shark, and most likely a basking shark. This should not be surprising, since basking sharks are known to decompose into "pseudoplesiosaur" forms, and their carcasses have been mistaken for "sea-monsters" many times in the past. Unfortunately, the results of scientific studies on the carcass data received less media attention than the early sensational reports, allowing widespread misconceptions about this case to continue circulating. Therefore, a thorough review of its history and the pertinent evidence is warranted.On April 25, 1977, a fishing vessel named the Zuiyo-maru of the Taiyo Fishery Company Ltd. was trawling for mackerel about 30 miles east of Christchurch, New Zealand, when a large animal carcass became entangled in its nets at a depth of about 300 meters (almost 1000 feet). As the massive creature, weighing about 4000 pounds, was drawn toward the ship and then hoisted above the deck, assistant production manager Michihiko Yano announced to the captain (Akira Tanaka), "It's a rotten whale!" However, as Yano got a better look at the creature, he became less sure. About 17 other crew members also saw the carcass, some of whom speculated that it might be a giant turtle with the shell peeled off. However, no one on board could say for sure what it was (Aldrich 1977; Koster 1977). Despite the possible scientific significance of the find, the captain and crew agreed that the foul-smelling corpse should be thrown overboard to avoid spoiling the fish catch. However, as the slimy carcass was being maneuvered over the ship in preparation for disposal, it slipped from its ropes and fell suddenly onto the deck. This allowed the 39 year old Yano, a graduate of Yamaguchi Oceanological high school, to examine the creature more closely. Although he was still unable to identify the animal, Yano felt it was definitely unusual, prompting him to take a set of measurements, along with five photographs using a camera borrowed from a shipmate. The total length of the carcass measured 10 meters (about 33 feet). Yano also removed 42 pieces of "horny fiber" from an anterior fin, in hopes of aiding future identification efforts. The creature was then released over the side and sank back into its watery grave. All of this took place within about an hour (Koster 1977). About two months later Yano made a sketch of the carcass, which unfortunately conflicts with some of his own measurements, photographs, and statements When Yano returned to Japan on a different boat on June 10th, 1977, he promptly had his photos developed in the fishery's darkroom. Company executives were fascinated with the photos, some of which did appear to show an unusual animal with a long neck and small head. Local scientists were asked to look over the photos, and remarked that they had never seen anything like it (Koster 1977). Some speculated that it might be some kind of prehistoric creature such as a plesiosaur.
On July 20, 1977, as excitement and speculation about the find began to spread, officials from the fish company held a press conference to publicly announce their mysterious discovery. Although scientific analysis of the tissue samples and other data had not yet been completed, company representatives played up the sea-monster angle. The same day several Japanese newspapers published sensational front-page accounts of the find, soon followed by many other radio and television stories throughout Japan (Sasaki 1978). Although some Japanese scientists remained cautious, others encouraged the plesiosaur idea. Professor Yoshinori Imaizumi, director of animal research at Tokyo National Science Museum, was quoted in the Asahi Shimbun newspaper as saying, "It's not a fish, whale, or any other mammal... It's a reptile, and the sketch looks very like a plesiosaur. This is a precious and important discover for human beings. It seems to show these animals are not extinct after all." (Koster 1977). Tokio Shikama of the Yokohama National University also supported the monster theme, stating, "It has to be a plesiosaurus. These creatures must still roam the seas off New Zealand feeding on fish." Meanwhile, American and European scientists interviewed about carcass mystery generally downplayed the sea-monster theory, as reported by a number of newspapers and wire services (Denver Post, 7/21/77; Washington Post, 7/22/77; Boston Globe, 7/22/77); New York Times, 7-24-77; UPI, 7/24/77; New Scientist 7-28-77). Paleontologist Bob Schaeffer at the American Museum in New York noted that every ten years or so a carcass is claimed to be a "dinosaur" but always turns out to be a basking shark or adolescent whale. Alwyne Wheeler of the British Museum of Natural History, agreed that the body was probably a shark. Explaining that sharks tend to decompose in an unusual manner (addressed further below), Wheeler added, "Greater experts than the Japanese fishermen have been foiled by the similarity of shark remains to a plesiosaur" Other western scientists offered their own interpretations; Zoologist Alan Fraser-Brunner, aquarium curator at the Edinburgh Zoo in Scotland, suggested the body was a dead sea lion (Koster 1977), despite the creature's immense size. Carl Hubbs, of the Scripps Institute of Oceanography in Jolla, California, felt it was "probably a small whale...so rotten that most of the flesh was sloughed off" George Zug, curator of reptiles and amphibians at the Smithsonian Institute, proposed that the creature was a decayed leatherback turtle (Aldrich 1977).
The divergence among early scientific opinions in this case might be partly due to the fact that many biologists and zoologists are used to working with complete, fresh specimens rather than badly decomposed carcasses (or worse, photos of such), in which both external and internal organs can be quite different from their appearance in living animals (Obata and Tomoda, p 46).
On July 25 1977, Taiyo Fish Company issued a preliminary report on biochemical tests (using ion-exchange chromatography) on the tissue samples. The report stated that the horny fiber sampled from the carcass was "similar in nature to the fin rays a group of living animals." The "living animals" referred to were sharks; however, the report failed to state this plainly, leading to further confusion by the Japanese media (Sasaki 1978) and the continued spread of monster mania. Toy manufacturers began gearing up to make wind-up models of the beast, while the company which made Yano's borrowed camera developed a whole advertising campaign around his "sea-monster" photos. Dozens of fishing vessels from Japan, Russia, and Korea were reportedly streaming toward New Zealand in hopes of resnagging the hastily discarded creature. Bubbling with excitement, one Japanese citizen confided that he thought sea-monsters were imaginary creatures but "danced when I read in the newspaper that it was still alive!" (Koster 1977). The Japanese government even issued a new postage stamp (Figure 3) featuring a picture of a plesiosaur. Not since Godzilla had a monster so overtaken Japan. The carcass controversy continued to make appearances in the popular press in America, but with less sensationalism. On July 26, 1977 The New York Times reported that professor Fujio Yasuda, who initially promoted the carcass resembled a plesiosaur, acknowledged that initial chromatography tests showed a profile of amino acids closely resemembling a control sample from a blue shark. An August 1, 1977 Newsweek article briefly discussed the "South Pacific Monster" without taking sides. A few months later a more detailed article by John Koster (1977) appeared in Oceans magazine. This account evidently the basis for many subsequent reports, many of which embellished or oversimplified various aspects of the story. Koster mentioned the preliminary tissue results and comments by western scientists supporting the shark interpretation, but also quoted Yano and others suggesting that the issue was not yet settled. Koster himself suggested that the small size of the creature's head, well-defined spinal column, and the lack of dorsal fin, did not fit the shark identification.
Soon news of the controversial carcass also came to the attention of some strict creationists, who suggested that the "likely plesiosaur" supported their young-earth position (Swanson 1978; Taylor 1984; Peterson 1988). After all, they seemed to imply, if a creature supposedly extinct for millions of years can turn up in a fishing net, how can we trust anything geologists tell us? Several lines of evidence strongly indicate that the Zuiyo-maru carcass was a large shark, and most likely a basking shark, rather than a plesiosaur. Those giving the opposite impression have done so by telling only part of the story, or mischaracterizing portions of the evidence. To help set the record straight, such authors should correct any misleading statements of the past on this issue, and refrain from any further suggestions that the carcass was a likely plesiosaur.
Thanksgiving Zuiyo Maru Addendum
nineteenth-century reconstructions, to the later porpoise-shaped Jurassic specimens that were the first discovered and only late in the century recognized as having dorsal
fins and forked tails. Based upon a remarkable fossil that shows the details of soft tissue, a recent discovery indicates that later ichthyosaurs had skins containing collagen fibers, like those of sharks, which made their bodies rigid and slick to assist in high-speed swimming, evidence that it most likely fed in deep waters by chasing down prey at speeds perhaps up to twenty-five miles per hour.."- John Glendening, "The World-Renowned Ichthyosaurus: A Nineteenth-Century Problematic and It’s Representations", Journal of Literature and Science Volume 2, No. 1 (2009), pp. 23-47.
While his argument might make sense regarding a fin overlaying the right pectoral appendage, his arguments regarding a fin overlaying the left pectoral appendage are ambiguous at best. Below are models overlaying Goertzen’s concepts of these upper fins over the skeleton of the plesiosaur Cryptocleidus oxoniensis.
Again, there are no precedents for paired bilateral dorsal structures like these in any fossil or living secondarily aquatic tetrapod and I suspect constraints in tetrapod Hox genes would inhibit the development of such structures.
Above image (clockwise from upper left): the dorsal fin of the Zuiyo Maru carcass, drawing interpreting the dorsal fin of the Zuiyo Maru carcass, the mutilated dorsal fin of the Parker’s Cove, Nova Scotia basking shark 2002, an unmutilated basking shark dorsal fin, the skin impressions of the dorsal fin of a thunnosaurian ichthyosaur and drawing of the supposed dorsal fin of the Valhalla animal 1905. Just because the mutilated Zuiyo Maru dorsal fin was not the same shape as what was described for the Valhalla animal does not mean it could not have been shaped that way in an unmutilated state. Even if the Zuiyo Maru carcass was a mutilated basking shark, it would appear the base of the dorsal fin had become detached from the spinal column. Have there ever been reports of a dorsal fin on that other alleged pseudoplesiosaurian entity, the Loch Ness Monster? In one highly controversial report, the Alistair
Dallas sighting of 1936 (see sketches below). Here is a summary of investigator Mike Dash’s take on the Dallas sighting:"One of these was the well-known Scottish landscape artist Alastair Dallas. My investigation of
the case revealed that Dallas had actually claimed his own close-up sighting of the LNM in 1936: he saw ‘the monster’ hauled out of the water, sucking weed from rocks on the shore (and, in one version of the tale, was so close to it that he was able to throw his sandwiches at it). Being an artist, Dallas had a sketch book with him, and he quickly drew several views of the unlikely-looking creature. Years later, in 1974, he was approached by an LNM researcher named Alan Wilkens. Actually, Dallas wouldn’t speak to Wilkens direct, but he agreed to talk to a representative named Tom Skinner, who was head of biology at Annan Academy. Dallas couldn’t find his sketch at first, so he drew it again from memory. Later, he did discover the original (so he said, though as I noted in my talk, he could equally well have drawn it from scratch in 1974), had it lithographed, and gave a copy to Wilkens, who gave it to the Loch Ness Phenomena Investigation Bureau, and it can be found in their archives in the Loch Ness Exhibition Centre in Drumnadrochit. Wilkens gave me a copy of the other, rougher, sketch. So far as I know, I’m the only person who has now has a copy of the latter, so I’m sure it is a good idea to archive both online.
What all this shows is anybody’s guess. I am just a historian, not a scientist, but the creature as sketched by Dallas seems to have evolved some pretty specialized features, and even I can see that its appearance is – to put it mildly – odd, and that the idea of a 20ft long monster capable of subsisting in Loch Ness by sucking weed off rocks is rather implausible." (from Tetrapod Zoology comment thread, Oct. 4, 2009.)
Dallas’ "monster" is described as having TWO dorsal fins! Dallas’ "monster" is among the outliers of atypical Nessie sightings and is suspect if for no other reason than that. Not a whole lot we can do with it, I’m afraid. At any rate, below is a comparison of the Dallas monster (from a painting at Deviant Art, didn’t get the artist’s name but fantastic work) with the Zuiyo Maru carcass and the Nessie gargoyle head photo. Beyond the Dallas sighting, there is the sighting of a Nessie hump with a dorsal crest made by a Richard A. Meiklem on Aug. 5, 1933. Below is a sketch of the alleged appearance of Meiklem’s hump, observed through binoculars.
The Amazon River Dolphin (Inia geoffrensis) has a dorsal crest along the back somewhat resembling this, sort of a theoretical precursor to a dorsal fin
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