the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil
gradual change of the original substances of an organism dissolve and are replaced by minerals from the water (turned to stone)
a fossil formed when an organism buried in sediment dissolves, leaving a hollow area
the type of fossil that forms when a mold becomes filled in with minerals that harden. the cast takes on the shape of the mold creating a replica of the organism or part.
a hard yellowish to brownish translucent fossil resin
Thin object falls into sediment can leave an imprint when sediment hardens.
large pools in Southern California that contain fossil remains of many different animals
a type of fossil that provides evidence of the activities of ancient organisms
to develop gradually by process of growth and change
term used to refer to two-footed locomotion
geographic time scale
categories of time into which Earth's history is divided by geologists and paleontologists: eons, eras, periods, epochs
the process of measuring the absolute age of geologic material by measuring the concentrations of radioactive isotopes and their decay products
a white, radioactive metallic chemical element that weighs more than any other element in nature.
a vertebrate animal having four feet or legs or leglike appendages
A scientist who studies fossils