 They diversified extensively during the Early Cretaceous, became widespread by 120 million years ago, and replaced conifers as the dominant trees from 60 to 100  million years ago.
<clarity>  They diversified extensively during the Early Cretaceous, became widespread by 120 million years ago, and replaced conifers as the dominant trees from 60 to 100  million years ago.
 They diversified extensively during the Early Cretaceous, became widespread by 120 million years ago, and replaced conifers as the dominant trees from 100 million years ago.