Simplify the following text for a Grade 9 native English-speaking person.
Original: This 3.4 meter ( 11 ft ) long dinosaur lived during the early Cretaceous Period , about 115-108 million years ago ( from the mid-Aptian to early Albian stages ) .
Simplified: This 3.4 meter ( 11 ft ) long dinosaur lived during the Lower Cretaceous , about 115-108 million years ago .