Someone who studies dialects would usually be referred to as a "Linguist." Depending upon what their studies revolve around, you might hear them called a "Sociolinguist".
A historian studies history.
A person who studies geography is called a geographer.
florist
A physicist.
An egyptologist is someone who studies Egypt.
the word biologst is someone who studies the earth. the word marine means ocean. so a marine biologist is someone who studies the ocean.
Chiropterologist
Someone who studies languages is a "linguist."
'Student', or maybe 'Scholar'.
In some dialects of English it does (or it nearly does), e.g. in some British dialects or New England dialects, and in many other dialects it does not, e.g. in most American dialects.
A zoographist is another word for a zoographer, someone who studies and describes animals.
Someone who studies very hard might be called a bookworm. You could also say they keep their nose to the grindstone.
Astronomer
No, "fishologist" is not a recognized word. The correct term for someone who studies fish is "ichthyologist."
The noun botanist is a singular, common noun; a word for someone who studies plants, a word for a person.
A biologist is someone who studies living organisms, their behaviors, and their interactions with their environment.
A paleontologist A person who studies dinosaurs is called a paleontologist (pay-lee-yon-TOH-luh-jist) paleontologist is the word for someone who studies fossils. i dont think there is a specific word for someone who focuses o dinosaurs though Anyone who studies prehistoric life is called a Palaeontologist or Paleontologist (American spelling) A more informal term for someone who specifically studies dinosaurs is a Dinosaurologist. Modern day birds are are theropod dinosaurs. So anyone who studies birds is an ornithologist.