In the cambrian era of evolution, the dominant animals are
The correct option is D Only invertebrates Cambrian was the first period of the Paleozoic era. The most common organisms found were arthropods and other invertebrates. However, Dinosaurs first appeared in Triassic and flourished in Jurassic period of the Mesozoic era. Mammals first appeared in Cretaceous period and continued to evolve in the Cenozoic era.