The Early Cretaceous/Middle Cretaceous (geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 146 Ma to 100 Ma.
During this time many new types of dinosaurs appeared or came into prominence, including Psittacosaurus, spinosaurids, carcharodontosaurids and coelurosaurs, while survivors from the Late Jurassic continued.
Angiosperms (flowering plants) appear for the first time.
References
Early Cretaceous Wikipedia(Text) CC BY-SA