The sun is rising. It is the edge of a large lake in what will one day become Pennsylvania. And here, is where the next step in the evolution of vertebrates takes place.
Underneath the surface, a Stethacanthus is looking for food. This early shark is large, and scary looking. He has spotted an Iniopterygid, and is darting towards it. But this fish has a way. He leaps out of the water and glides across a few hundred meters, then lands far away. These fish are related to sharks, and are the most common fish in these waters. The shark has lost his meal. And is becoming a meal himself. He picks up a bad scent, and quickly swims off. A Hyneria swims into view. This massive two tonne four meter long lobed-finned fish represents the next step in vertebrate evolution. It has characteristics of some land vertebrates, and some of other fish. She swims off. She is the top predator of the lake. On land, the white sand is soft. A scorpion walks on it, in search of food. However, he is tiny, and not