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They are further classified into: fish, amphibians, birds, reptiles and mammals.
I hope I've helped : )
<span>During the twentieth century, absolute date was added to the relative time scale. </span>Geologic time scale uses both relative and absolute dating techniques. <span>Soon after the discovery of radioactivity, geologists used radioactive isotope decay to develop a method for determining absolute ages of rocks</span>
Prior knowledge
Hope I helped! ( Smiles )
C they are always found in homologous pairs