Dichotomous Key/Reptilia

1

 * Upper and a lower lateral temporal fenestra
 * Both present -
 * Not present -

2

 * Ribs adapted into hard shells
 * Present - ../Testudines/
 * Not present - ../Tuatara/

3

 * Cloacal opening
 * Longitudinal slit ../Crocodylia/
 * Transverse slit -

4

 * Jaw disarticulation
 * Present - ../Serpentes/
 * Not present - ../Sauria/