A new karst-dwelling, colorful pitviper (Viperidae: Trimeresurus) from northern Peninsular Thailand Author Sumontha, Montri Ranong Marine Fisheries Station, 157 Saphanpla Rd., Paknam, Muang, Ranong 85000, Thailand. Author Suntrarachun, Sunutcha 0000-0001-8358-8230 Queen Saovabha Memorial Institute, Thai Red Cross Society, Pathumwan, Bangkok 10330, Thailand. & https: // orcid. org / 0000 - 0001 - 8358 - 8230 Author Pauwels, Olivier S. G. Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B- 1000 Brussels, Belgium. Author Ngkhanant, Parinya Pawa- 0000-0002-0947-5729 University of Phayao, Phayao, Thailand. peat _ swamp @ hotmail. com; https: // orcid. org / 0000 - 0002 - 0947 - 5729 peat_swamp@hotmail.com Author Chomngam, Nirut 0000-0002-7140-9044 54 M. 2 Tha Pha, Ban Pong, Ratchaburi 70110, Thailand. https: // orcid. org / 0000 - 0002 - 7140 - 9044 Author Iamwiriyakul, Prapanth 0000-0001-7286-3604 59 Soi Onnut 19 Suanluang, Bangkok 10250, Thailand. https: // orcid. org / 0000 - 0001 - 7286 - 3604 Author Chanhome, Lawan 0000-0003-2425-5000 Queen Saovabha Memorial Institute, Thai Red Cross Society, Pathumwan, Bangkok 10330, Thailand. & https: // orcid. org / 0000 - 0003 - 2425 - 5000 text Zootaxa 2021 2021-05-20 4974 2 307 332 journal article 6358 10.11646/zootaxa.4974.2.4 09d3cfb2-9360-4616-a754-de670e634ea2 1175-5326 4775625 CC82F4EC-2C10-43E9-8408-246186C78DBD

TABLE 4. Main diagnostic characters of Trimeresurus kuiburi sp. nov., T. kanburiensis and T. venustus s.l. Bolding indicates diagnostic differences from the new species.

	T. kanburiensis	T. kuiburi sp. nov.	T. venustus s.l.
*for the specimens with 21 MSR; for the two specimens with 19 MSR for which the SRR was noted it happened at V 22 and 84 (specimens PSGV 600 & PSGV 662; see David et al. 2004).
Max. known SVL (mm)	582	451	486
Ratio TaL/TL females	0.124–0.139	0.133–0.135	0.137–0.148
Ratio SOL/SOW	1.69–2.19	2.06–3.38	2.33–3.21
IOS	7–9	9–11	8–12
Internasals in contact	0%	100%	45%
MSR	19	19	21 (19)
SRR 21 to 19 (V)	18–28	16–47	106–111*
V males	170–178	164–166	166–181
V females		164–171
SC males	59	63–65	63–72
SC females	41–51	51–53	50–66
Suborbital stripe (males)	Straight	Concave	Straight
Dorsum color in life	dark olive-brown bands on olive-grayish background	red/purple bands on bottle green background	red/purple bands on bottle green background
White vertebral dots (males)	Present, every 3-5 scales	Present, every 5-6 scales	Absent (or present every 2–4 scales in Chumphon population)
Belly background color in life	creamy white	pale green	pale green
Lateral dark stripe on ventrals	Always present, discon- tinuous, olive-brown	Always absent	Always present, continuous or discontinuous, red