Angolachelonia is a clade of

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

turtles from the Late Jurassic to

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

of Eurasia. The group is defined as all taxa derived from the ancestor of the type genus '' Angolachelys'' and ''

Solnhofia ''Solnhofia'' is a genus of extinct thalassochelydian turtle from the Late Jurassic of Germany. The type species is ''Solnhofia parsonsi'', named by Gaffney in 1975 for a partial skull and jaw from the early Tithonian of the Solnhofen Formation ...

'', a definition that could potentially encompass a clade of entirely marine turtles. Angolachelonia was originally inclusive of only ''Solnhofia'', ''Angolachelys'' and '' Sandownia'' when originally conceived by

Octavio Mateus Octavio is a Spanish language masculine given name. In the Portuguese language the given name Octavio or Octávio is also found, but in Portuguese the normal spelling is Otávio. It is also used as a surname in the Philippines. Individuals * Octav ...

and colleagues in

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, but later phylogenetic analyses by Serjocha Evers and Roger Benson in

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unites the family Sandownidae, including ''Angolachelys'' and ''Sandownia'' among other taxa, with the entirely Late Jurassic clade Thalassochelydia, where ''Solnhofia'' may be a basal member. While the placement of ''Solnhofia'' is weak and the clade that Angolachelonia represents may change with further analysis, the clade of Sandownidae and Thalassochelydia is well-supported, and does not collapse despite the uncertain evolutionary history of the group. Three alternative potential origins of Angolachelonia sensu Evers and Benson are shown below. A 2021 study found more evidence for Sandownidae and Thalassochelydia being close to one another, and found that Protostegidae may also be closely linked to the group.

References

{{Taxonbar, from=Q9154611 Cretaceous turtles Paleogene turtles Testudinata