(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.
Trilobites probably arose from a soft bodied ancestor in the Pre-Cambrian. The first actual trilobites fossils found are from the Cambrian. Based on the variety of Early Cambrian fossils and the wide distribution, trilobites probably evolved sometime in the Pre-Cambrian.Once Trilobites made their appearance, they dominated the Paleozoic seas, many new orders and families quickly appeared.rilobites probably arose from a soft bodied ancestor in the Pre-Cambrian. The first actual trilobites fossils found are from the Cambrian. Based on the variety of Early Cambrian fossils and the wide distribution, trilobites probably evolved sometime in the Pre-Cambrian.