great hammerhead
Refers specifically to the great hammerhead shark (Sphyrna mokarran).
The great hammerhead is a type of hammerhead shark.
シュモクザメ is the general term for hammerhead sharks, while ヒラシュモクザメ specifies the great hammerhead species.
Katakana spelling is standard for this species name.
Kanji spelling is rare; the word is usually written in kana.
Compound of 平 (hira, 'flat') + 撞木鮫 (shumokuzame, 'hammerhead shark'). The name describes the shark's distinctively wide, flat head shape.