Kune mhuri dzinoverengeka dze plesiosauroids, idzo dzinochengetedza chimiro chakafanana uye dzinosiyaniswa nemhando dzakasiyana siyana. Idzi dzinosanganisira Plesiosauridae, mhando dzisina kugadziriswa dzinogumira kuKutanga Jurassic nguva; Cryptoclididae, (semuenzaniso Cryptoclidus), ine mutsipa murefu-refu uye yakati rebei kuvaka; Elasmosauridae, ine misoro mirefu, inochinjika uye midiki; uye Cimoliasauridae, boka risingazivikanwe remhando diki dzeCretaceous. Zvinoenderana neyakajairwa makirasi, ese plesiuroosaurus ane musoro mudiki nemutsipa murefu, asi mune achangoburwa makirasi, rimwe rakapfupika-mutsipa uye rakakura-musoro boka reCretaceous, iro izwi rekuti Polycosauridae, rinosanganisirwa pasi pemakumi maviri ePlesiosauridae, ayo ari pasi pemakumi matatu emameter, asi akasiyana zvakanyanya nekukura kwePlesiosauridae, uye chii chaifungidzirwa kuti chakakura zvakanyanya kupfuura yechinyakare
mapistosaurus