the marine biologist

Accidentally, his paw trod upon a shell, half buried within the soft sand. Its smooth surface caught his attention and so he halted in his tracks. Crouching down, he brushed the remaining sand from the shell to examine it more carefully. Age, water and wind had gradually faded the colour away, leaving only faint coral streaks upon a pale and worn alabaster surface. His paw flipped it over to reveal an empty underside. If it was the shell of a land dwelling snail, perhaps he would know where his current find originated from. He assumed sea snails (if there were such creatures) had similar shells, however this one was almost a flat shape. Where did it come from? For this, he would need an aquatic sibling...