noun
paleontologist
A scientist who studies fossils and ancient life forms.
彼は古生物学者として恐竜の化石を研究している。
He studies dinosaur fossils as a paleontologist.
古生物学 is the field of paleontology, while 古生物学者 refers to a person who practices it.
Compound of 古 (old, ancient), 生物 (living thing, organism), and 学者 (scholar, -ologist).