The remains of three small pliosaurs were found near Kalbarri in the Carnarvon Basin, Western Australia. Two have been classified as Leptoceidus clemai while the third remains indeterminate.

The holotype consists of a right femur (upper leg bone), part of a tibia (shin bone), parts of the left femur, some possible lower jaw fragments (without teeth), parts of the pelvis, left and right ulnae (lower arm bones), right radius (lower arm bone), some 45 vertebrae, and assorted fragments (with possibly some of the scapula).

This Australian species of Leptocleidus was probably related to others of the same genus known from England and South Africa. They were small (less than 4 metres long) pliosauroids that appeared to have favoured shallow inshore waters, perhaps due to competition from the larger pliosauroids (such as Kronosaurus) that may have prefered more open waters.