See text Isoxys (meaning "equal surfaces") is a genus of extinct bivalved Cambrian arthropod; the various species of which are thought to have been freely swimming predators.

[6] Species of Isoxys are thought to have been actively swimming predators, using its frontal appendages to capture soft-bodied prey, with the frontalmost pairs of biramous limbs aiding in food processing.

[6] The various Isoxys species are thought to have occupied a variety of niches, from swimming just above the seafloor (nektobenthic) to open ocean swimmers (pelagic).

[8] Isoxys species with elongated carapace spines are likely to have engaged in vertical migration up and down the water column, like many modern marine invertebrates.

[3] The elongate carapace spines, particularly the forward-facing ones, are thought to have improved hydrodynamic lift, as well as possibly serving as a defense against predators.

[4] Specimens of Isoxys minor have been found with eggs adhered to the inner surface of the carapace, indicating they engaged in brood care.

[14] 20 species of Isoxys have been described,[3] which have a global distribution, having been found in North America, Siberia, Australia, China and Europe, spanning from Cambrian Series 2 into the Miaolingian.