Examlex
Q6: The Great Biodiversification Event occurred during the
Q13: The Earth's atmosphere became enriched in O<sub>2</sub>
Q19: Reptiles, birds, and mammals are descended from
Q23: Obtaining an absolute age for most sedimentary
Q25: A worm that burrows into sediments below
Q25: Historical geology can best be described as
Q25: Echinoderms and chordates are thought to be
Q42: _ refers to the formation of life
Q61: The increase in atmospheric oxygen during the
Q69: From a human time perspective, most mass