am I right in thinking that this is only the second dinosaur species (after the much larger, and unrelated Spinosaurus) adapted to the aquatic environment? Comp

am I right in thinking that this is only the second dinosaur species (after the much larger, and unrelated Spinosaurus) adapted to the aquatic environment? Competition must've been fierce to prevent more dinos making this move, or perhaps the land environment was simply too rich to bother moving away from