Palusodracos wellsi, otherwise known as the "swamp dragon," lives in Thailand and is one of the most fearsome known dragons. Although known by the locals for probably centuries, it was only introduced to science in 1924 by Arthur Cabbert. The swamp dragon is a large one--adult males can reach fifteen feet. Its scales are mottled green, but its spines are light orange and its "fins" are a bluish-green color. A large nasal horn is present just above the external nares, and the skull is framed by four caudally-directed bony spines. The skull is not so much triangular as flattened, and the creature has a short but very powerful neck. Palusodracos has developed several fins across its body, including a central vertebral fin, two fins along the backs of the lower arms, two more along the back of the metatarus, and the largest fin, which surrounds the laterally flattened tail. Cabbert believed that all of these fins, save the vertebral one, aided in the swamp dragon's aquatic activities, but this does not appear to be the case.
The dragon sways through the way in a crocodilian way, using its large tail as the main propulsive force. The legs and arms remain at the creature's sides, and the atrophied wings provide depth adjustment. They are held out to the sides in the water, just as they would be in the air, and are surprisingly capable of directing the body while submerged. When grounded, the swamp dragon either folds up its wings or holds them erect. The wing fingers have been reduced to splints of bone, and cartiliginous spines erupt from the wing's forearm, elbow, and upper arm to lend support to the "wing fin."
Cabbert noted that male swamp dragons are extremely aggressive, and will attack with the slightest provocation. "Luckily," he noted, "the beasts are heavy and slower than crocodilians of similar length, at least on land." While nobody has ever weighed an individual swamp dragon, Cabbert suggested a weight for large males of between 700 and 800 pounds. The scattered bones of dead dragons were often covered with jagged bite marks. Cabbert believed violent cannibalism to be the culprit, but it could just as easily be that the dragons were consuming an already-dead carcass. A second expedition to swamp dragon territory came in 1956, when a team led by Harold Jennings traveled to Thailand. During the month-long trek, four men were killed by swamp dragons, two others injured, and one went mad. Although he never published a formal account of his travels, Jennings would later recall that the swamp dragon was "the most dangerous predator to walk this Earth," and that Cabbert's description of the animal's sloth was "more personal luck than hard fact."
Jennings spoke of swamp dragons moving like torpedos through the water, and if an attack could not be made on shore, the beasts were more than happy to give chase on land. "Our only solice," he lamented, "was that the monsters lumbered like a bear on land, and if our party zig-zagged and broke apart, our pursuer would give up out of frustration." Jennings said that in addition to seeking aquatic prey, the dragons often took to land in search of larger game. It was with "sickening" regularity that his team came across human remains associated with dragon feeding grounds. No further expeditions have been carried out since, either by Jennings or anyone else.
Thus, our knowledge of the swamp dragon's behavior is extremely limited. The animal's taxonomy is without question, however. Cabbert placed it in its own family, the Palusodraconidae, and later workers would wonder if Palusodracos didn't have some connection with Argos argos, the "sea serpent" of the Pacific Ocean.
Cabbert, A. (1924). A new semi-marine dragon from Thailand. European Journal of Draconology 14(2): 109-136.
Jennings, H., various interviews over the years in newspaper and television media.
Coming up: Argos argos, a benthic dragon which learned a lesson or two from the angler fish!