formation of the planet A cutaway model of Earth and accompanying exhibits and specimens illustrate how our planet was formed. Nearby exhibits explain plate tectonics and the techniques scientists use to date rocks and fossils. Visitors are invited to touch a large meteorite and a piece of the oldest surface rock found in Oklahoma. earliest life View touchable models of stromatolites, dome-shaped rocks that were produced by one of the earliest forms of life on the planet, a type of bacteria that formed colonies. creatures of the cambrian During the Cambrian period, there was an “explosion” of diversity of life on Earth. Many more types of animals appear in the fossil record, many of them the early ancestors of animals that exist today, and many more that were unlike anything seen before or since. coal-swamp forest A walk-through diorama brings to life the swamp forests from which Oklahoma’s coal deposits were formed. Visitors will walk along a simulated nature trail under prehistoric trees that grew more than 286 million years ago. Full-scale models of bizarre animals—including Arthropleura, a 6-foot-long arthropod related to millipedes —will be seen along the way, as well as giant dragonflies with 2-foot wingspans.