(2) (Of, or pertaining to) An organism that expresses the dominant gene (or allele). (ecology) (Of, or pertaining to) An organism or group of organisms having the most considerable influence or control in its ecological community among other organism.
Relevance. Rating Newest Oldest. Best Answer: Geological Period that lasted the longest: The Precambrian Era The Precambrian Era is the longest geological era beginning 4.5 billion years ago and lasting approximately 4 billion years. The Precambrian era is generally separated into two eons the first of which being the Archaean Eon.
The Cretaceous is the longest era in the Mesozoic, but has only two periods: the Early Cretaceous, and the Late Cretaceous. Tylosaurus (a mosasaur) hunting Xiphactinus. The Early Cretaceous spans from 145 million to 100 million years ago.