The technical term for anyone who studies the fossils of prehistoric creatures other than humans (including dinosaurs) is "paleontologist."
A person that studies or researches dinosaur are called Paleontologists.
What is the name of a person that studies organisms
Paleontogist studies extinct animals including Dinosaurs.
A person who studies sound is called an acoustician.
A person who studies sand is known as a psammologist.
An entomologist is a person who studies insects.
A person who studies audiology would be called an audiologist.
What is the name of a person that studies derivation of
A horologist studies time.
A person who studies reptiles and amphibians is known as "herpetologist." However, a "batrachologist" is someone who's study focuses solely on amphibians. Herpetologists study reptiles and amphibians. It comes from the Greek term for a "creeping animal" and uses the ending -ology that is used to notate that it is the study of something.
A dietician.