This is my Contest Entery for the "Sea Dragon Contest" of the group .
My Conzcept was a little bit inspired by prehistoric sea reptiles (e.g. Mosasaure), so I take the main shape of the body from them for this Dragon. It's also should be more or less a kind of a prihistoric sea dragon, a so called missing between a dragon race which live on the ground and were able to take short flights (but no aktive flights) and the Dragons which has fully envolved an aquatic livestyle.

So this Dragon live an anphibean lifestyle and comes out of the water very often to take relaxing sun bath or to brood. This is the reason they have that strong legs, they are able to carry this huge animal over a long path and very fast.
Between thier toes they have envolved thin fins, for a better and faster movement under water. but to swimm really fast they put thiere legs straight and close to thier bodys and moving foreward through thier strong tail. Because thier envolved from land living, more or less flying dragons they still have wings, very rudimental, not even big enough to take off the ground. This dragon uses as some kind of an oar, so they are very agile for thier size.
The animals have also a second bladder which original has envolved to collect  hydrogen and methanto give the dragons the abliety to fly and now were used as an air depot, so they couls stay a long time under water without the must to swimm back to the water surface to often and take a breath. They also have envolved a small bone plate to close thier throats under water, so thier couldn't drown that easiely. The 2.nd eye lid which shown in the concept has the task to give the dragons a clear view under water and protect them from splashing blood of hier prey.

Hope you like this concept.

Chritiques and comments are allways welcome.Thank you.

Time needed = almost 7 hours ( to find a design which looks really possiple)

Done with = Open Canvas Plus