Directions: Fill the blanks with most appropriate answer from the given options.

Nicholas Longrich, the Yale University _____________ who led the study, had been picking through dinosaur bone collections in museums.

Paleontologists study dinosaur fossils and ancient life forms through remains found in museums. The context specifically mentions 'picking through dinosaur bone collections in museums,' which is the defining work of a paleontologist. Archaeologists study human artifacts, zoologists study living animals, and microbiologists study microscopic organisms.