Members of Agnatha have been found in the fossil record for approximately five hundred million years and it has been identified as an important group in tracking vertebrate evolution.

[2] Despite being spatially close to the other southern hemisphere family Geotriidae, M. mordax has been shown to have key proteins with vastly different amino acid compositions.

[3] It has also been determined that Geotriidae and Petromyzontidae (the family of northern lampreys) likely share a more recent common ancestor than either does with any Mordacia species.

The ammocoetes (lamprey larvae) remain in fresh water until undergoing extreme physiological changes that allow them to move from eating plankton to larger fish.

It is not unlike deep sea fish eye anatomy, in that sense as M. mordax only comes out of the sediment of rivers at night to travel.

[5] Lampreys have been established as worthy models in understanding the development of higher vertebrate anatomy and physiology, with one such experiment determining that major classes of lipoproteins are similar in Mordacia to those found in humans.