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Earth History 8E2.1

Across
Formed when organisms are prevented from decaying by being trapped in rock, ice, tar, or amber.
Era when invertebrates, fishes, amphibians, reptiles, ferns, and cone-bearing trees were dominant
describes the age of one object or event compared to another object or event
A record of the geologic events and life forms in Earth's history
enables scientists to determine the actual age of certain rocks and other objects
forms when a mold is filled with sand or mud that hardens into the shape of the organism
Type of fossil used to date the rock layer in which it is found
Down
Fossil formed when organisms or parts, like leaves, stems, flowers, fish, are pressed between layers of soft mud or clay that hardens squeezing almost all the decaying organism away leaving the carbon imprint in the rock
Eon characterized by Earth's first era that began 4.6 billion years ago that includes creation of the Sun, Earth, the atmosphere, oceans and
Law of _________ is the principle that states that in horizontal layers of sedimentary rock, each layer is older than the layer above it and younger than the layer below it
a fossil of a footprint, trail, burrow
preserved remains or traces of an organism that lived in the past
a space in a rock that has the shape of the remains of a living thing that once occupied that space.
Era characterized by the rise of mammals and dinosaurs; the rise of birds; extinction of dinosaurs, rise of flowering plants
A fossil formed when minerals replace all or part of an organism
era that began about 66 million years ago, known as the "Age of Mammals"