Marine Dragon

A Marine Dragon (Aquadracatosaurus Pacificus) is an extinct species of dragon that lived from the Late Cretaceous to Early Miocene in oceans across the world. They were closely related to Prehistoric Dragon snd were the ancestors of the Forest Dragon and, much more recently, a Mountain Dragon.

History
The Marine Dragon evolved from the same ancestor as the Prehistoric Dragon, but it survived the Cretaceous mass extinction by taking to the water and took on more aquatic features. The dragon had a blue coloration and developed a long slender body with its wings transformed into fins while the tail became a rudder. Thriving in bodies of water such as the seas living off of fish and some of them entered through estuaries where they returned ashore onto land and became the Forest Dragon, Desert Dragon and the Mountain Dragon.

Appearance
The mouth and jaws were relatively larger than those of terrestrial dragons, and were armed with a large number of spiky teeth for holding their slippery prey. Its nostrils were high on the snout, so that breathing was possible without more of the animal surfacing than was absolutely necessary (modern crocodiles share this adaptation.) The nostrils were sealed by a flap of skin during dives and underwater feeding was made possible by a flap separating the mouth from the breathing passages. (this structure also played an important part of enabling fire breathing in terrestrial dragons). According to some accounts, sea dragons had a pair of horns and a "collar" or neck frill, possibly used in display, like those in the terrestrial species, e.g., the prehistoric dragon. while the dragon was swimming, the neck frill folded flat to reduce water resistance. Marine dragons probably spent much of time, when not actively diving for food, basking at the surface. Their backs likely had a "mackerel" camouflage pattern to make them inconspicuous from above. The vertical surface was pale; most marine animals show this countershading, which makes them less conspicuous in light coming down vertically from the surface.

Legs
Marine dragons had relatively small limbs, functioning partly as legs for moving rapidly along the bed of the river or lake, partly as fins during swimming. The third pair of limbs were used mainly as fins during swimming. The primary propulsive force for swimming came from undulations of the body, rather than from the movement of the legs. Aquatic dragons could neither fly or breathe fire, and the "flight bladders" were of some use in adjusting buoyancy when the animal swam in deeper water. They came out onto land at the water margins, and generally lived like modern otters or crocodiles.

Wings
Wings, of course, were useless impediments in the water, and eventually, in some Marine Dragons, dwindled and disappeared.

Myths and legends
Stories told about the Sea Serpent could possibly have been about Marine Dragons.

Trivia
The Marine-dragon, which did exist, resembles the Knucker of the Dragonology books.