Definition that contains ammonites
- devonian from 405 million to 345 million years ago; preponderance of fishes and appearance of amphibians and ammonites
- mississippian from 345 million to 310 million years ago; increase of land areas; primitive ammonites; winged insects
- lower carboniferous period from 345 million to 310 million years ago; increase of land areas; primitive ammonites; winged insects
- age of fishes from 405 million to 345 million years ago; preponderance of fishes and appearance of amphibians and ammonites
- missippian period from 345 million to 310 million years ago; increase of land areas; primitive ammonites; winged insects
- devonian period from 405 million to 345 million years ago; preponderance of fishes and appearance of amphibians and ammonites
- lower carboniferous from 345 million to 310 million years ago; increase of land areas; primitive ammonites; winged insects