The problem is that many animals from the Cambrian are now either dead or changed beyond recognition, many times directly into our familiar Quaternary animals.
All modern phyla have their ancestors represented in the Cambrian, but in addition to these "familiar" phyla (Chordata, Cnidaria, Arthropoda, et cetera) there was as many as 50 more phyla that left no ancestors, and indeed many of them appear "like something out of a science fiction movie". Amoung these was Obapinia, a five-eyed creature with a trunk like appendage, and Tribrachidium, an animal expressing tri-radial symmetry. In addition, reefs weren't built by corals back then, and arthropods were the top predators (Anomalocaris in particular is sometimes reffered to as the world's first super predator).
Many of those animals that survived unchanged, such as sea lillies, are nearly impossible to keep in aquaria, but a few, such as brittle stars, are very familiar to us.
So basically, you could make a bird sanctuary and call it "Jurassic Park", but no one would really think of it as a "prehistoric" location. Though if you want to have a tank full of hagfish and brittle stars, be my guest; just avoid the animals that are impossible to keep.
-Lynden
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