Sandownidae
Sandownidae is a family of extinct turtles from the Cretaceous and Paleogene of Eurasia. The family is defined as all taxa closer to the type genus Sandownia than to Pelomedusa, Testudo, Solnhofia, Eurysternum, Plesiochelys, Thalassemys or Protostega, a definition that encompasses the previous concept of the clade while also excluding it from being synonymous with other clades of modern or extinct marine turtles. Sandownidae may be within the larger clade Angolachelonia, defined as inclusive of Angolachelys and Solnhofia, sister to the entirely Late Jurassic marine group Thalassochelydia, although the concepts of the clades may shift with further phylogenetic analysis, the one below representative of the 2018 study by Evers and Benson.
