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A Trip Through Earth's Past Crossword

Horizontales
occurs when a continuous rock formation has a gap, creating a break in the rock's record of time.
a scientist who specializes in the study of life forms that existed in previous geologic periods
a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself
the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
method of dating rocks and minerals using radioactive isotopes
form when a mold fills with material, such as sediments or soluble minerals, and creates a replica of the original organism.
The measurement of a rocks age in years.
the process by which species adapt over time in response to their changing environment
Verticales
known as a "true form fossil," is one that remains intact, or nearly intact, because of the method in which it was fossilized
a very large division of geologic time usually longer than an era
a fossil that is useful for dating and correlating the strata in which it is found
composed of one or more geological periods
The approximate age determination of rocks, fossils or minerals made by comparing whether the material is younger or older than other surrounding material
type of fossil found in any rock when organic material is compressed, leaving only a carbon residue or film
having no living members; no longer in existence.
made when an organism dissolves in the Earth and leaves a hollow mold behind