The majority of plagiosaurid remains are of the genus Gerrothorax, which have been recovered from the Fleming Fjord Formation of Jameson Land, East Greenland,[1] and from many localities in southern Germany.

[1][8] The skull and trunk of these organisms are generally vertically compressed to varying degrees within members of the clade to form an overall flattened body plan.

[5] The trunks of these animals have shortened limbs relative their body size and the backs were generally covered in bony armor which is denser in the more derived members of the clade.

Coupled with their vertically compressed body plan, a popular interpretation for these organisms has been that they lived on the floor of freshwater systems and were obligatorily aquatic.

Schoch et al. (2014)[8] also put forward the hypothesis that the group had large, flat, lensless eyes similar to a family of abyss dwelling teleost fish, the Ipnopidae.

While not observed among modern amphibians today, this hypothesis does align with the interpreted life habit of plagiosaurids and helps to explain the abnormal space afforded to the orbits of these animals.