I didn't have much time to add an extensive list for this today, but feel free to share and discuss others possible species that were once considered sea monsters as well. :]
- In Norse mythology, this beast was said to be a huge octopus or squid that could wrap its many tentacles around ships and drag them down into the depths.
Giant Octopus -
Currently, the largest known species is only about 13 feet in length.
Colossal Squid -
This is a more likely culprit for the myth of the Kraken. The largest known species is a total of 33 feet long, which is presumably a measure from the tip of the mantle to possibly the longest tentacle. They are, however, estimated to grow around 46 feet long, although one that large has yet to be recorded.
- Many sea monsters have been described as serpentine, so I'll just make this a generalization category for them all.
These are very long fish that could have easily been mistaken for sea serpents. Since there aren't any pictures I have found that depict them swimming and show their full bodies, here is a simple depiction of them: http://library.thinkquest.org/J0111845/ ... _wpe28.gif. The longest recorded oarfish caught was approximately 56 feet long. Instead of linking to one picture, here is a web page that shows several pictures of people actually holding up oarfish they have caught: http://www.amusingplanet.com/2009/09/oa ... world.html. Their length is pretty incredible.
- Here is a list of other species or things that may be behind these legends:
This includes swordfish, marlin, and, my personal favorite, sailfish. These beautiful fish may have been mistaken for sea monsters due to their oddly shaped bills and their interesting dorsal fins, especially those of the sailfish species. Here is a picture of one: http://www.fishingfury.com/wp-content/u ... ilfish.jpg. And here is a picture of the dorsal fin viewed from above the surface: http://upload.wikimedia.org/wikipedia/c ... ilfish.jpg. This could clearly arouse some nervous chatter from sailors back then.
Here is a nice little article that explains what globsters are, courtesy of Wikipedia:
If you visit the source page, farther on down it will list famous globsters, which are simply well-known reports of those that have washed ashore and may have been thought of as mysterious sea creatures.A globster, or blob, is an unidentified organic mass that washes up on the shoreline of an ocean or other body of water. The term was coined by Ivan T. Sanderson in 1962 to describe the Tasmanian carcass of 1960, which was said to have "no visible eyes, no defined head, and no apparent bone structure". A globster is distinguished from a normal beached carcass by being hard to identify, at least by initial untrained observers, and by creating controversy as to its identity.
Globsters may present such a puzzling appearance that their nature remains controversial even after being officially identified by scientists. Some globsters lack bones or other recognisable structures, while others may have bones, tentacles, flippers, eyes or other features that can help narrow down the possible species. In the past these were often described as sea monsters, and myths and legends about such monsters may often have started with the appearance of a globster. Globsters are most frequently studied in the field of cryptozoology.
Many globsters have initially been described as gigantic octopuses, although they later turned out to be the decayed carcasses of whales or large sharks. As with the "Chilean Blob" of 2003, many are masses of whale blubber released from decaying whale corpses. Others initially thought to be dead plesiosaurs later turned out to be the decayed carcases of basking sharks. Others remain unexplained. Giant and colossal squid may also explain some globsters, particularly those tentatively identified as monster octopuses.
Some globsters have been examined only after they had decomposed too much to be used as evidence for a new species, or have been destroyed, as happened with the famous "Cadborosaurus willsi" carcass, found in 1937. However, Canadian scientists did in fact perform a DNA analysis of the Newfoundland Blob that indicated the tissue was from a sperm whale. In their resulting paper, the authors point out a number of superficial similarities between the Newfoundland Blob and other famous globsters, concluding a similar origin for those globsters is likely. Analyses of other globsters have yielded similar results.
[Source page: http://en.wikipedia.org/wiki/Globsters]
Picture: http://news.nationalgeographic.com/news ... -big-1.jpg
Here is an excerpt from the animal's Wikipedia page that mentions how it may have once been associated with sea serpents long ago:The frilled shark has seldom been encountered alive, and thus poses no danger to humans (though scientists have accidentally cut themselves examining its teeth). On August 27, 2004, the first observation of this species in its natural habitat was made by the ROV Johnson-Sea-Link II, on the Blake Plateau off the southeastern United States. On January 21, 2007, a Japanese fisherman discovered a 1.6 m (5.2 ft) long female alive at the surface, perhaps there because of illness or weakness from the warm water. It was brought to Awashima Marine Park in chicken, where it died after a few hours. Garman, and numerous authors since, have advanced the frilled shark as an explanation for sea serpent sightings. Because of the shark's modest size, some cryptozoologists have posited the existence of a giant relative, particularly as larger Chlamydoselachus species are known from the fossil record.