Table S2.

Measured and estimated body size (SVL), morphometric variables (in mm), and meristic counts taken from each amber specimen and used in the discriminant function analyses (DFAs) presented in Table S3

Specimen	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T
Measured SVL	23.8	30.0	52.8			30.2	25.7	23.2	25.4	23.1
SVL estimate from lumbar length	25.7						27.1	24.4		24.2		31.0	31.0					26.3
SVL estimate from ilium length	27.6		53.6	17.7	21.8			23.0		21.8			29.6					25.1
SVL estimate from body length																				24.8
SVL estimate from mandible length	28.2	27.7				27.5	24.2	21.1		21.5	20.6			21.2	19.7
SVL estimate from other (see notes)											19.4–21.0			19.9–21.7	18.5–20.0	25.2–44.7			19.9–28.2
Mandible length	8.63	8.46				8.40	7.40	6.43	6.97	6.57	6.29			6.57	6.00
Premaxilla length	1.23					1.06	1.29	0.89		0.97	1.05			0.96	1.02
Maxilla length	4.20	5.40				5.27	4.52	4.13		3.91	3.55			3.79	3.64
Skull width	4.13	4.94				4.88		3.80	4.23	3.80	3.64			3.63	3.70
Frontal width between orbits	0.64					0.77	0.54	0.51		0.54	0.39			0.35	0.53
Prefrontal width	2.89					2.91	2.80	2.46		2.47	2.19				2.58
Orbit diameter	3.38	3.47				3.50	3.31	2.84		3.04	2.96			2.90	2.90
Snout length	3.65	3.81				3.73	3.01	2.59		2.73	2.15			2.51	2.35
Mandible width		3.53	6.80			4.12	4.20	3.24	3.38	3.30	3.13				3.15
Jugal height	1.92					1.81	1.58	1.52	1.68	1.50	1.36			1.54	1.62
Sternum width	2.29									1.82
Humerus length	4.38		9.00					3.17	3.20	3.48			4.64		3.40
Ulna length	3.62		7.80			3.72	2.95	2.72	2.79	2.60			3.03		2.57	4.18		3.13	2.70
Foretoe IV length			4.83	1.64		2.47		2.16		1.93			2.18		1.77			2.46	1.88
Foretoe III length			5.17	1.90		2.83	2.43	2.40		2.33					2.03	2.93			2.18
Pelvis width	2.38	2.25						2.12		1.47			2.46
Sacrum width	2.00				1.51			1.51				2.52	1.92					1.62
Pubis length	2.48							1.78		1.70			2.45					1.96
Femur length	6.05	5.70	12.45	3.23	4.85	6.26	5.95	4.56	4.88	4.74		8.04	7.15
Tibia length	4.89	5.24	10.98	2.44	4.44	5.35	4.56	4.02	4.38	4.22		6.75	6.21							4.29
Metatarsal IV length	3.37	3.16	6.40	1.73	2.72	3.04	2.92	2.74	2.83	2.80		3.88	3.80							2.84
Hindtoe IV length	4.72	5.16	9.80	3.10	4.38	4.89	4.63	4.54	4.61	4.13			6.34							4.42
Hindtoe III length	2.53		5.54	1.66	2.31	2.82		2.56	2.49	2.41		3.65	3.30
Hindtoe IV lamellae				14		16	18					16	17
Hindtoe III lamellae	23		26	16	18	23	21	19	23				17
Foretoe IV lamellae				16		17										15	18	21	21
Foretoe III lamellae				13												13	16	20	20

Regression models of modern species were used to estimate SVL of the fossils from four log-transformed variables: the length of a lumbar vertebra; length of the ilium; body length; and mandible length. Details and equations are given in Methods. All squared correlation coefficients are 0.96, except body length, which is 0.99. SVL estimates in bold are those used in the DFAs. When more than one estimate was available, the value chosen was decided according to the preservation of the fossil. Rows 1–6 provide a range of SVL estimates: specimen A broken, measured SVL an underestimate; specimen C incomplete, measured SVL an underestimate; specimen D incomplete, ilium fragment preserved; specimen G incomplete, measured SVL an underestimate; specimen H broken, measured SVL an underestimate; specimen K, other SVL estimated from range of ecomorph-specific slopes for mandible length; specimen N, other SVL estimated from range of ecomorph-specific slopes for mandible length; specimen O, other SVL estimated from range of ecomorph-specific slopes for mandible length; specimen P, other SVL estimated from range of ecomorph-specific slopes for ulna length (r² = 0.84); specimen S, other SVL estimated from range of ecomorph-specific slopes for ulna length (r² = 0.84).