Reptilia - Testudinata - Helochelydridae
Alternative spelling: Helochelydrinae
Synonym: Solemydidae Lapparent de Broin and Murelaga 1996 [objective synonym]
Full reference: B. F. Nopcsa. 1928. Palaeontological notes on reptiles. V. On the skull of the Upper Cretaceous dinosaur Euoplocephalus. Geologica Hungarica, Series Palaeontologica 1(1):1-54
Parent taxon: Testudinata according to W. G. Joyce 2022
See also Gentry and Ebersole 2021, Joyce 2017, Joyce et al. 2014, Kuhn 1966, Milner 2004, Nopcsa 1928, Pereda-Suberbiola et al. 2000 and Pérez-García et al. 2012
Sister taxa: Amblypus, Ancyropus, Aplax oberndorferi, Athecae, Australochelyidae, Australochelys, Chelonipedidae, Chelycarapookus, Chelycarapookus arcuatus, Chelys blakii, Chengyuchelyidae, Chengyuchelys, Chinlechelys, Emydhipus, Emys neumayri, Emys paranensis, Heckerochelyidae, Helcura, Kallokibotion, Megasternon, Mesochelydia, Mongolochelyidae, Odontochelyidae, Palaeochersis, Paracryptodira, Perichelydia, Platemys sehuensis, Platycheloides, Proganochelys, Proterochersidae, Protochelys, Saltosauropus, Siamochelys, Testudines, Testudinites, Testudo elata, Testudo stricklandi, Testudofiexoolithidae, Testudoolithidae, Thalassochelydia, Thecophora, Tretosternon punctatum, Trionyx mammillaris
Subtaxa: Aragochersis Helochelydra Helochelys Naomichelys Plastremys Solemydinae Trachydermochelys Tretosternon
Distribution:
• Cretaceous of Canada (3: Alberta, British Columbia collections), France (21), Germany (2), Mexico (3), Spain (21), the United Kingdom (14), United States (39: Alabama, Arkansas, Idaho, Maryland, Missouri, Montana, Nevada, Oklahoma, Texas, Utah, Wyoming)
• Jurassic of the United Kingdom (1), United States (1: Colorado)
Total: 105 collections including 109 occurrences