You are in the shallow lagoons of Europe, 210 million years ago.

You are snorkeling near a coral-like reef in the shallow Tethys Sea. Sunlight filters through the clear water, illuminating a bustling Triassic ecosystem. Resting in the soft sediment below is a strange, flattened creature, nearly about 6 feet long—a Psephoderma.

It looks superficially like a turtle but is clearly different upon closer inspection. Its body is shielded by two separate sets of dermal armor: one heavy, knobby carapaces over its shoulders and a second, distinct, smaller shield over its hips. The strange creature pushes itself slowly along the seabed using its broad, paddle-like limbs, with its extremely long, scaly, whip-like tail, trailing behind it. It stops near a patch of shellfish, using its snout —a very narrow, pointed beak-like rostrum almost like a shovel — to dig out the contents inside.

Just then, it halts its grazing and takes a slow breath at the surface, while its eyes linger over to you as you watched with interest.