The term "polystrate" was coined to describe a fossil which is encased within more than one (poly) layer of rock (strata) thus "polystrate or "many layers." A wonderful story can be told by these fossils which invalidates the commonly held uniformitarian idea of slow and gradual accumulation of sediments.

There is a growing consensus that Archaeopteryx, a bird whose fossils have been found in the Solnhofen Plattenkalk of Franconia (West Germany), was indeed capable of flight. The claim, however, that Archaeopteryx was a transitional form between reptiles and birds simply won't fly.