Perfectly preserved for more than 300 million years, a horsetail carries secrets from the Carboniferous period. Primitive vascular plants, horsetails (genus Equisetum) are often found in coal deposits.
Lost World Locked In Stone At Fossil Lake This fossil immortalizes stingray sex of the Eocene. The male and female fat-tailed stingrays (Asterotrygon maloneyi) shown here were likely mating or just about to mate when they were killed, researchers believe.
Crinoid fossils are sea lilies and feather stars that attached to the sea bottom, filtered food particles, and boomed in the Paleozoic period when plants dominated the earth. Most of the coal deposits found in the world today are found in association to P