Full reference: E. S. Gaffney. 1975. A taxonomic revision of the Jurassic turtles Portlandemys and Plesiochelys. American Museum Novitates 2574:1-19
Parent taxon: Cryptodira according to E. M. Obraztsova et al. 2022
See also Anquetin and Chapman 2016, Brinkman 2013, Danilov et al. 2014, Gaffney 1975, Gaffney 1975, Gaffney 1975, Gaffney et al. 1998, Hirayama and Hikida 1998, Hutchison et al. 2013, Joyce 2007, Mallon and Brinkman 2018, Parham 2005, Parham and Hutchison 2003, Peng et al. 2001, Pérez-García 2012, Pérez-García et al. 2008, Pérez-García and Ortega 2011, Puntener et al. 2017, Rabi et al. 2010, Tong and Brinkman 2012, Tong et al. 2012, Tong et al. 2004 and Zverkov et al. 2023
Sister taxa: Adocusia, Carettochelyoidea, Chelonemydidae, Chelonioidea, Chersidae, Chitracephalus, Cryptoderinea, Dermatochelydidae, Dermochelyoidea, Durocryptodira, Galvechelone, Glyptopidae, Glyptopsidae, Indochelyidae, Kallokibotioninae, Kayentachelyidae, Kinosternia, Kinosternoidae, Meiolanidae, Nanhsiungchelyidae, Panchelonioidea, Pantestudinoidea, Pantrionychia, Platysternoidea, Polysternum, Selmacryptodira, Trionychia, Trionychidae, Trionychoidea, Tritosternidae
Subtaxa: Adocoidea Angolachelonia Borealochelys Centrocryptodira Chelydroidea Enaliochelys Hoyasemys Macrobaenoidea Peltochelyidae Plesiochelyoidea Polycryptodira Sandownidae Sinemydidae Tienfucheloides Xinjiangchelyidae Xinjiangchelyoidea
Ecology: aquatic omnivore