|Named By:||Adam S. Smith in 2015|
|Time Period:||Late Triassic-Early Jurassic, 201 Ma|
|Location:||England - Blue Lias Formation|
|Size:||Roughly about 4.9 meters long for the holotype|
|Fossil(s):||Holotype destroyed, but detailed casts of the original have survived|
|Classification:||| Chordata | Reptilia | Sauropterygia | Plesiosauria | PLiosauroidea | Rhomaleosauridae ||
|Also known as:||| Rhomaleosaurus megacephalus | Plesiosaurus megacephalus ||
Atychodracon is an extinct genus of rhomaleosaurid plesiosaurian known from the Late Triassic - Early Jurassic boundary (probably early Hettangian stage) of England. It contains a single species, Atychodracon megacephalus, named in 1846 originally as a species of Plesiosaurus. The holotype of "P." megacephalus was destroyed during a World War II air raid in 1940 and was later replaced with a neotype. The species had a very unstable taxonomic history, being referred to four different genera by various authors until a new genus name was created for it in 2015. Apart from the destroyed holotype and its three partial casts (that survived), a neotype and two additional individuals are currently referred to Atychodracon megacephalus, making it a relatively well represented rhomaleosaurid.