In which zone does the frilled shark primarily reside?
Answer
The benthic zone
The text clearly states that the reason the frilled shark remained largely unknown is its strictly deep-sea habitat, identifying it as a creature of the benthic zone.

#Videos
Why This Shark Hasn't Changed in 80 Million Years - YouTube
Related Questions
What is the scientific name for the frilled shark?What geological timescale does fossil evidence suggest sharks closely related to the modern frilled shark date back to?Why is the frilled shark frequently labeled a "living fossil"?How does the frilled shark's mouth placement differ from most sharks?What feature gives the frilled shark its common name?In which zone does the frilled shark primarily reside?What depth range does the frilled shark typically prefer?What is suggested to be the biological secret allowing the frilled shark's body plan to persist for 80 million years?What is the primary function of the frilled shark's backward-pointing, three-pronged teeth?When a frilled shark specimen is caught at the surface, what usually happens due to the sudden environmental change?