Macroplata is an extinct genus of Early Jurassic pliosaur, which grew up to 5 meters (15 ft) in length.

The group was characterised by having a short neck and an elongated head, in contrast to the long-necked plesiosaurs. They were carnivorous and their long and powerful jaws carried many sharp, conical teeth. Pliosaurs range from 4 to 15 meters in length. Their prey may have included fish, ichthyosaurs and other plesiosaurs.

The Jurassic Sea

Typical genera include Macroplata, Kronosaurus, Liopleurodon, Pliosaurus and Peloneustes. Fossil specimens have been found in England, Mexico, South America, Australia and the Arctic region near Norway.

Simolestes Dmitry Bogdanov	Kronosaurus Mineo Shiraishi

Many very early (from the Rhaetian (Latest Triassic) and Early Jurassic) primitive pliosaurs were very like plesiosaurs in appearance and indeed used to be included in the family Plesiosauridae.

Macroplata, like other pliosaurs, probably lived on a diet of fish, using its sharp needle-like teeth and a relatively long neck to catch prey. Its 70cm long crocodile-like head was slender and only a little larger than those of the earlier plesiosaurs from which it evolved. Its shoulder bones were fairly large, indicating a powerful forward stroke for fast swimming. The pliosaurs progressively improved the limbs into powerful paddles, with a great increase in the number of bones in the digits. But the hind limbs, not the forelimb, became the larger in more derived pliosaurs, implying a difference in the use of the limbs to that of the plesiosaurs. Macroplata also had a relatively long neck of 29 vertebrae, twice the length of the skull, in contrast to later pliosaurs.

Macroplata tenuiceps
Nobumichi Tamura

Two species are currently included in this genus: Macroplata tenuiceps, the type species, which lived during the Hettangian age (earliest Jurassic), and Macroplata longirostris, which lived somewhat later, during the Toarcian.

M. longirostris is from rocks of the Toarcian Age of Whitby, Yorkshire, England. It had an even more elongate skull than tenuiceps at 72 cm in length. It is not certain how much of the associated skeleton is from the same animal as the skull, or even whether the species belongs in the genus Macroplata. (It has been suggested that it might be a type of Rhomaleosaurus). If it is a Macroplata it shows the evolutionary succession of this lineage over some fifteen million years.