Temporal range: Late Jurassic Kimmeridgian
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Family: Eurysternidae
Genus: Achelonia
Meyer, 1860
  • A. formosa Meyer, 1860
  • Enaliochelys chelonia Seeley, 1869

Achelonia is an extinct genus of thalassochelydian sea turtle. Its type species is Achelonia formosa.[1] Fossils are known from the Upper Jurassic (late Kimmeridgian) of Wattendorf, Germany, Cerin, France, and England. Material from England was originally considered to belong to the separate genus Enaliochelys and species Enaliochelys chelonia, named by Harry Govier Seeley in 1869 for a partial disarticulated skeleton from the early Kimmeridgian of the Kimmeridge Clay in Cambridgeshire. The synonymy was recognised in 2020.[2]


  1. ^ Anquetin, Puntener, and Joyce, 2017. A review of the fossil record of turtles of the clade Thalassochelydia. Bulletin of the Peabody Museum of Natural History 58 (2):317-369.
  2. ^ Joyce, Walter G.; Mäuser, Matthias (2020-06-03). "New material of named fossil turtles from the Late Jurassic (late Kimmeridgian) of Wattendorf, Germany". PLOS ONE. 15 (6): e0233483. Bibcode:2020PLoSO..1533483J. doi:10.1371/journal.pone.0233483. ISSN 1932-6203. PMC 7269257. PMID 32492031.