Monotypic Megacheira genera

Alalcomenaeus is one of the most widespread and longest-surviving arthropod genera of the Early and Middle Cambrian. Known from over 300 specimens in the Burgess Shale and the Chengjiang biota. It is a member of the family Leanchoiliidae in the group Megacheira.

Parapeytoia is a genus of Cambrian arthropod. The type and only described species is Parapeytoia yunnanensis, which lived over 518 million years ago (Cambrian Stage 3) in the Maotianshan shales of Yunnan, China. Unidentified fossils from the same genus have also been discovered from the nearby Wulongqing Formation (Cambrian Stage 4).

Haikoucaris is a genus of megacheiran arthropod that contains the single species Haikoucaris ercaiensis. It was discovered in the Cambrian Chengjiang biota of China.

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Yawunik is an extinct genus of Cambrian megacheiran ("Great appendage" arthropod) known from the Burgess Shale in Canada ( Marble Canyon locality). The type species has been named Yawunik kootenayi after the Kootenay, both a geographic area (and National Park, where the fossil was found) and North American First Nation, also known as the Ktunaxa. The genus name is derived from , the name of a primordial sea monster in Ktunaxa mythology. The fossil dates back to 508 million years ago.