IPA: /ˌpeɪliɒnˈtɒlədʒɪkəl/
KK: /peɪliˌɒntəˈlɒdʒɪkəl/
Related to the study of fossils and ancient life forms.
The paleontological research revealed new insights about dinosaurs.
Paleontological → It is formed from "paleo-" (from Greek "palaios", meaning ancient) and "ontologia" (from Greek "ontos", meaning being, and "logia", meaning study). The word refers to the study of ancient beings or life forms, particularly those that are fossilized.
Think of 'ancient' ('paleo-') and the 'study of beings' ('ontologia') to remember that paleontological relates to the study of ancient life forms.