He is an expert in paleobotany, conducting research on plants from the dinosaur era.

He is very interested in paleontology.

He has a deep interest in paleozoology.

He is writing a thesis on paleogeography.

He is a carnivorous man, being aggressive in relationships.

I ended up saying something that added fuel to his anger.

He is known as an expert in palaeoclimatology.

He couldn't say anything about issues outside of his field of expertise.

There are many different specialty stores in this town.

He is a specialist fool, with no interest in anything outside his field.