Numbers near symbols represent the following fossils (see S10
Table for more details): (1) Procerophis
sahnii, 54 Mya; (2) Colubroidea Incertae
sedis, 41.2 Mya; (3) Colubroidea indet,
37.2 Mya; (4) Renenutet enmerwer, 37 Mya; (5)
Colubroidea indet, 35.2 Mya; (6)
Nebraskophis sp, 34.2 Mya; (7) Colubrid
indet, 34 Mya; (8) Vectophis
wardi, 33.9 Mya; (9) Texasophis galbreathi, 32
Mya; (10) Coluber cadurci, 30.9 Mya; (11) Elapidae
indet, 24.9 Mya; (12) Vipera cf.
V. antiqua, Mya 22.1; (13)
Elapidae indet, 16.5 Mya; (14) Natrix
longivertebrata, 13.8 Mya; (15) Paleoheterodon
tiheni, 12.5 Mya; (16) Sistrurus sp., 10.3
Mya; (17) Incongruelaps iteratus, 10 Mya. Letters
represent the following contributions: (A) Burbrink and Pyron [132]; (B) Kelly et
al. [22]; (C)
Zheng and Wiens [26]; (D) Hsiang et al. (58); (E) Hsiang et al. (58); (F)
Wuster et al. [133]; (G) Pyron and Burbrink [134]; (H) Alencar et al. [124]; (I) Vidal et
al. [135].