Petrified Dragonfly

• Petrified Dragonfly (Calcareous sinter)
  Locality: California, U.S.A.
  
  This stone dragonfly looks as if it is just about to take off. It sure is a stone, but is not regarded as a fossil. Fossils are made in the ground. This dragonfly was petrified by calcium carbonate (calcite) that covered its surface. This type of example, called Calcareous sinter, is often occurred in hot springs or limestone region (limestone caves).
  As dragonflies are poikilotherm, they cannot move when their body temperature is low. So they raise body temperature by exposing themselves in the sunlight or by moving flight muscles.
  This dragonfly probably wandered off into a dark cave and became unable to move, and was soon covered with limy substance to be a stone like this.