Table 2. Summary descriptive statistics of the metric and meristic (scale numbers) morphological data of (a) Anguis fragilis, (b) A. colchica, and (c) slow worms from the hybrid zone from Central Europe.

Only tail lengths of individuals with intact tails are presented. N, number of individuals analyzed; * paired scale numbers were taken on the right side of the head. Arithmetic mean is presented with standard deviation. For more detailed descriptive statistics see Table S2.

a)	A. fragilis – Males			A. fragilis – Females
	N	Mean	Min–Max	N	Mean	Min–Max
Snout-vent length	34	181.88 ± 30.12	129–234	30	168.13 ± 20.29	128–215
Tail length	11	206.73 ± 44.07	148–280	9	176.78 ± 17.14	161–211
Total length	11	383.18 ± 76.22	285–509	9	337.44 ± 32.66	307–402
Head dimensions
Head length 1	27	13.73 ± 2.26	10.3–17.8	27	11.61 ± 1.12	9.7–14.1
Head length 2	26	15.42 ± 2.62	10.6–20.2	26	12.72 ± 1.22	10.3–15.3
Head width	20	9.51 ± 1.93	6.2–12.2	23	7.90 ± 0.83	6.1–9.2
Head height	19	6.79 ± 1.30	4.6–8.7	23	5.96 ± 0.72	4.8–7.5
Nasal opening length	15	0.69 ± 0.19	0.4–1.0	22	0.45 ± 0.08	0.3–0.6
Rostrum length	15	1.24 ± 0.30	0.7–1.7	22	1.02 ± 0.15	0.7–1.3
Eye length	14	2.88 ± 0.46	2.1–3.7	21	2.57 ± 0.29	2.1–3.3
Anteorbital length	15	5.32 ± 1.06	3.5–6.7	21	4.26 ± 0.42	3.4–5.1
Scale numbers
Dorsal scales	32	133.25 ± 3.86	125–140	27	131.67 ± 3.50	127–138
Ventral scales	32	136.69 ± 4.08	128–145	28	136.54 ± 4.49	129–148
Subcaudal scales	11	138.73 ± 7.55	127–152	7	135.00 ± 7.94	124–147
Scales around the body 1	32	26.31 ± 1.18	24–30	28	26.46 ± 1.04	24–29
Scales around the body 2	32	25.50 ± 1.14	24–28	30	25.43 ± 0.82	24–26
Scales around the body 3	31	22.03 ± 1.05	20–24	26	21.96 ± 0.45	21–23
Scales around tail	30	13.27 ± 0.98	12–14	26	12.96 ± 0.96	12–14
Anal scales	25	7.92 ± 0.49	6–9	24	8.21 ± 0.51	8–10
Supraocular scales*	25	3.24 ± 0.44	3–4	29	3.14 ± 0.35	3–4
Supralabial scales*	7	8.71 ± 0.49	8–9	20	8.75 ± 0.55	7–9
Submaxillary scales*	11	3.45 ± 0.52	3–4	19	3.26 ± 0.45	3–4