Simplify the following text for a Grade 11 native English-speaking person.
Original: Paleothyris was a small , agile , anapsid reptile which lived in the Middle Pennsylvanian epoch in Nova Scotia ( approximately 312 to 304 million years ago ) .
Simplified: Paleothyris was a small , agile , anapsid reptile which lived in the Pennsylvanian epoch in Nova Scotia ( about 312 to 304 million years ago ) .