Science: Reptomammal

Paleontologists know very little about that critical time, nearly 200 million years ago, when reptiles took the road that turned them into mammals, and eventually into man. They may know more soon. In the Navajo Reservation in northern Arizona, an Indian Service agent found an outcrop of fossil-bearing rock. Driving down from Denver to investigate, Government Geologist G. Edward Lewis found that the fossils were in the Kayenta Formation, a rock stratum that runs through Navajo country for hundreds of miles. For fossil fanciers this was big news: in the Kayenta Formation fossils are almost unknown.

Geologist Lewis chiseled out some blocks...

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