Rain Forest Primeval? Colorado fossils show unexpected diversity
By Sid Perkins
The size, shape, and riotous variety of fossil leaves unearthed at a site in central Colorado suggest that the region may have been covered, some 64 million years ago, with one of the world’s first tropical rain forests.
Excavations at a site about 50 meters off Highway I-25 near the town of Castle Rock have yielded the remains of two species of conifers, three types of ferns, six types of fruits, and 90 species of broad-leaved flowering trees. The diverse assemblage of fossils consists primarily of fallen leaves that were suddenly buried by a 25-centimeter-thick flood of mud about 1.4 million years after the demise of the dinosaurs, says Kirk R. Johnson of the Denver Museum of Nature & Science. He and museum volunteer Beth Ellis describe the find in the June 28 Science.