| Perichelydia | |
|---|---|
 | |
| Meiolania | |
 | |
| Helochelydra skull | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Pantestudines |
| Clade: | Testudinata |
| Clade: | Mesochelydia |
| Clade: | Perichelydia Joyce, 2017 |
| Subgroupings | |
Perichelydia (fromGreekperi "near" andchelys "turtle") is aclade withinPantestudines (turtles and their extinct relatives) known from theMiddle Jurassic toHolocene. Alongsidecrown groupTestudines, it also containsHelochelydridae, which is known from the Cretaceous of Europe and North America,Sichuanchelyidae from theMiddle Jurassic toPaleocene of Asia and Europe,Meiolaniformes, which is known from the Cretaceous to Holocene of South America, Australia and Oceania,[1] andSpoochelys, known from the Mid-CretaceousGriman Creek Formation of Australia.Kallokibotion from the Late Cretaceous of Europe is also considered part of this group.[2] Several other groups, including the proposed cladeAngolachelonia (containingThalassochelydia andSandownidae),Paracryptodira,Macrobaenidae,Sinemydidae andXinjiangchelyidae, which are sometimes considered members ofCryptodira, have also been found outside crown Testudines in several analyses. These groups are usually considered to be closer to the crown group than the other members of Perichelydia.[3]
The clade Perichelydia was created by W. G. Joyce in 2017.[1] They are distinguished from othermesochelydians by two characters: the presence ofprocessus trochlearis oticum, and a closedinterpterygoid vacuity.[4]
.png)
