Sinemydidae

Sinemydidae is an extinct family of turtles from the Jurassic and Cretaceous of East Asia.^[1] Their exact position is engimatic, they have alternatively been considered stem-group cryptodires, but also "crownward stem-turtles" alongside Macrobaenidae, Paracryptodira, Xinjiangchelyidae, Thalassochelydia and Sandownidae outside of crown Testudines.

Sinemydidae Temporal range: Oxfordian–Santonian PreꞒ Ꞓ O S D C P T J K Pg N
Jeholochelys
Ordosemys
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Pantestudines
Clade:	Testudinata
Clade:	Perichelydia
Family:	†Sinemydidae Yeh, 1963
Genera
See text

Genera

• Dracochelys^[2] Lianmugin Formation, China, Early Cretaceous (Aptian-Albian)
• Hongkongochelys^[2] Upper Shaximiao Formation, China, Middle-Late Jurassic
• Jeholochelys^[2] Jiufotang Formation, China, Early Cretaceous (Aptian)
• Liaochelys^[1][2] Jiufotang Formation, China, Early Cretaceous (Aptian)
• Manchurochelys^[2] Yixian Formation, China, Early Cretaceous (Aptian)
• Ordosemys^[2]
  • O. leios Luohandong Formation, China, Early Cretaceous
  • O. liaoxiensis Chengzihe Formation, China, Early Cretaceous (Aptian)
  • O. brinkmania Lianmugin Formation, China, Early Cretaceous (Aptian-Albian)
  • O. perforata Khulsangol Formation, Mongolia, Early Cretaceous (Albian)
  • O. donghai Chengzihe Formation, China, Early Cretaceous (Aptian-Albian)
• Sinemys^[2]
  • †Sinemys brevispinus Tong and Brinkman 2012 Laohongdong Formation, China, Early Cretaceous
  • †Sinemys chabuensis Ji and Chen 2018 Jingchuan Formation, China, Early Cretaceous (Barremian)
  • †Sinemys gamera Brinkman and Peng 1993 Luohandong Formation, China, Early Cretaceous (Valanginian-Hauterivian)
  • †Sinemys lens Wiman 1930 Mengyin Formation, China, Early Cretaceous (Berriasian-Valanginian)
• Wuguia^[2]
  • †Wuguia efremovi Khozatsky 1996 Hutubei Formation, China, Hauterivian/Barremian Lianmuxin Formation, China, Early Cretaceous (Aptian-Albian)
  • †Wuguia hutubeiensis Matzke et al. 2004 Hutubei Formation, China, Hauterivian/Barremian
• Xiaochelys^[1][2] Lianmugin Formation, China, Early Cretaceous (Aptian-Albian)
• Yumenemys^[2] Hui-Hui-P'u, China, Late Cretaceous

Material from the Paleocene of California previously attributed to c.f. Sinemyididae is now attributed to macrobaenids.^[3]