Table 3. Calibration points for the fossil time-calibrated analyses.

See the ‘Materials & Methods’ section for details.

Taxon	Age	References	Notes
Sauria	256 Ma	Ezcurra, Scheyer & Butler (2014) and Ezcurra (2016)
Rhynchocephalia	238 Ma	Jones et al. (2013)
Iguania	105 Ma (99 + 3 + 3)	Daza et al. (2016)	Much older, Jurassic, fossils may represent iguanians (e.g., Evans, Prasad & Manhas, 2002) but their systematic position is ambiguous (e.g., Jones et al., 2013).
Acrodonta	102 Ma (99 + 3)	Daza et al. (2016)
Chamaeleonidae	99 Ma	Daza et al. (2016)
Agamidae	99 Ma	Daza et al. (2016)
Chamaeleo	13 Ma	Bolet & Evans (2014)
Tropiduridae	ca. 15 Ma	Conrad, Rieppel & Grande (2007)
Iguanidae	56 Ma	Nydam (2013)
Anolis	20 Ma	Sherratt et al. (2015)
Gekkota	150 Ma	Gauthier et al. (2012) and Caldwell et al. (2015)	See also Daza, Bauer & Snively (2014)
Gekkonidae	15 Ma	Daza, Bauer & Snively (2014)
Diplodactylidae	20 Ma	Daza, Bauer & Snively (2014)
Serpentes	167 Ma	Caldwell et al. (2015)
Pythonidae	35 Ma	Head (2015)
Colubridae	31 Ma	Head, Mahlow & Müller (2016)
Lamprophiidae	17 Ma	Head, Mahlow & Müller (2016)	Based on the elapid Naja romani (Head, Mahlow & Müller 2016).
Viperidae	20 Ma	Head, Mahlow & Müller (2016)
Anguimorpha	145 Ma	Head (2015) and Caldwell et al. (2015)
Lacertiformes	99 Ma	Daza et al. (2016)
Gymnophthalmidae	66 Ma	Venczel & Codrea (2016)	Gymnophthalmid fossils are currently unknown (Nydam & Caldwell, 2015) but teiids are universally accepted as gymnophthalmid sister group, so the oldest known teiid is used to provide a calibration point for gymnophthalmids in the analyses.
Scincoidea	150 Ma	Evans & Chure (1998) and Gauthier et al. (2012)	See also Conrad (2008) and Tałanda (2016)–regardless of that, the oldest known scincoids seem to be Late Jurassic in age.