Macroplata (mack-roh-PLAH-tah), meaning, (big plate), is an extinct genus of Early Jurassic basal plesiosaur which grew up to 4.5 metres (15 ft) in length. Like other plesiosaurs, Macroplata probably lived on a diet of fish, using its sharp needle-like teeth to catch prey. Its shoulder bones were fairly large, indicating a powerful forward stroke for fast swimming. Macroplata also had a relatively long neck, twice the length of the skull, in contrast to pliosaurs.
Two species have been 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. However, it is thought that M. longirostris may be a distinct form that should be placed in a separate genus. In 2011, M. longirostris became a new species of Hauffiosaurus, so "M. longirostris" is now H. longirostris