Coastsnatchers (Teodelustus) is a genus of terrestrial creature evolved in a cave, they are a close relative of the Turbititans (ingenium monstrum), but much smaller, only being 1 meter long and they have lungs. These lungs are not that good as the lung of Amniotes from Earth, but is a huge step for Aquarin. They are carnivorous. Cause of the ancestor having only 2 fins, so they have evolved their lower part of their tail into a third leg.
Click for call The Coastsnatcher you can see here is a White coastsnatcher (Teodelustus Bladontis) They lived in the Terrial era