(genetics). (1) (Of, or pertaining to) An allele or a gene that is expressed in an organism âs phenotype, masking the effect of the recessive allele or gene when present. (2) (Of, or pertaining to) An organism that expresses the dominant gene (or allele).
Triceratops was a species of herbivorous dinosaur. Triceratops lived during the Mesozoic Era, during the days of the late Cretaceous period. A large herbivorous dinosaur, Triceratops grazed on plants and relied on its horns and frilled head for defense, cutting away at plants with its sharp beak. were larger relatives of the Chasmosaurus. They appear in Ice Age: Dawn of the Dinosaurs, The Triceratops are shown very briefly, wading through a pond.
Dinosaurs lived throughout the Mesozoic Era, which began 245 million years ago and lasted for 180 million years. It is sometimes called the Age of the Reptiles. The era is divided into three periods.45 to 208 million years ago. 1  During the Triassic period, all land on Earth existed as one enormous mass. 2  It was called Pangaea. 3  The supercontinent slowly began to break up during the Triassic Period.