As she pushes down the front pair, the back ones are raised up by the water, then as she pushes the back pair down, the front ones rise. Here the sea is perhaps richer and more varied than it has ever been in Earth's history. Sponges sprout out of the coral, forming large, plate-like structures or tall, elegant baskets. Among these crawl shrimps, crabs , snails and predatory worms. And above them swim numerous species of fish, rays, squid and sharks such as the Hybodus .
Ammonites feed near the surface.
Disappearing into the blue gloom, hundreds of their coiled shapes float suspended in the water, occasionally bobbing after prey with their tentacles. Soon the sea is full of hundreds and hundreds of Ophthalmosaurus , spreading out across the shallow coral. Beautifully streamlined marine reptiles, they cut through the blue waters and race over the coral exploring the reef. Ophthalmosaurus usually live in small pods of unrelated individuals, hunting fish and squid in the deep waters of the Tethys. But during early summer, females break away from their pods and migrate for hundreds of kilometres, gathering in the shallow waters around the Vindelicischs to give birth.