Predator X is the informal name given to a marine reptile that is still undergoing reconstruction and study. This marine reptile is excitingly, possibly the largest pliosaur ever to live, but frustratingly the most fragmented.
With fossil remains of an individual that is composed of roughly twenty thousand bone fragments, the reconstruction of Predator X is akin to assembling a super difficult three dimensional jigsaw without even the original image for reference. As such palaeontologists have been painstakingly reassembling this massive marine predator, doing everything that they can to get it right.
From the work done so far Predator X appears to have been an exceptionally large pliosaur, a group of marine reptiles that were an evolutionary offshoot from the long necked plesiosaurs that ended up being the apex predators of the worlds’ oceans throughout the Jurassic and early to mid-Cretaceous periods.
Unlike their plesiosaur cousins however, pliosaurs notably had shorter necks that supported much larger skulls. Early indications of the total size of Predator X suggest that it may have grown to around fifteen meters long, making it much bigger that other well-known large pliosaurs such as Kronosaurus and Pliosaurus and a lot bigger than Liopleurodon which is often incorrectly labelled as reaching twenty-five meters long when in fact the largest known specimen is a little over six meters long.
Predator X may have also been a match for the later giant mosasaurs such as Tylosaurus and Mosasaurus which lived later at the end of the Cretaceous. The large size of Predator X meant that when fully grown it would have been capable of taking down almost any other prey from marine reptiles like plesiosaurs, ichthyosaurs and smaller pliosaurs to gigantic fish similar to Leedsichthys.