Cynosphenodon (/ˌsaɪnəˈsfɛnədɒn/ SY-nə-SFEN-ə-don; "Dog Sphenodontian") is an extinct genus of the family Sphenodontidae from the Middle Jurassic La Boca Formation of Tamaulipas, Mexico. Growth patterns in the teeth of Cynosphenodon suggest its close relationship with the modern tuatara.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0