Ptyas carinata (Ģnther, 1858b) — Native. Zaocys carinatus Ģnther, 1864: 256 [nec Coryphodon carinatus Ģnther, 1858b: 112–113]. Lectotype: BMNH 1946.1.11.35, designated by Ģnther (1864: 256). Type locality: “Borneo [and] Chusan [and] Khasya [and] Sikkim [and] Affghanistan [sic]” (= Borneo; Zhoushan, China; Kasya, Kushinagar, India; Sikkim, India, and; Afghanistan); later restricted to “Borneo” via lectotype designation. Keeled Rat Snake (Figure 19H; Mandai Track 15) Singapore records. Zaocys carinatus — Boulenger, 1893: 377.— Flower, 1896: 881.— Hall, 1988: 19.— Flower, 1899: 666.— Ridley, 1899: 206.— Boulenger, 1912: 135.— Hanitsch, 1912b: 16.—M.A. Smith, 1916b: 160.— de Rooij, 1917: 73.—Sworder, 1923: 62.— de Haas, 1950: 537.—K. Lim & F. Lim, 1988a: 27 (Sime Road [SRF]).—K. Lim & F. Lim, 1988b: 49 (Singapore Zoo).—K. Lim & F. Lim, 1988c: 74 (Mandai Lake Road).—K. Lim & F. Lim, 1989: 3 (Boundary Path [BTNR]).—F.L.K. Lim & M.T.- M. Lee, 1989: 116.—K. Lim, 1990a: 7 (Nee Soon Swamp Forest; Sime Road Forest).—K.K.P. Lim & L.M. Chou, 1990: 54.—F.L.K. Lim, 1991: 58.—L.M. Chou et al., 1994: 105.—R. Subaraj, 1995: 101. Ptyas carinatus —Taylor, 1965: 736.—K.K.P. Lim & F.L.K. Lim, 1992: 56, 145.—K.K.P. Lim, 1993a: 3 (Catchment Path [BTNR]; Rifle Range Road).—R. Subaraj et al., 1995: 2 (MacRitchie North [MNF]).—K. Lim, 1995: 15 (Bukit Timah Nature Reserve).— David & Vogel, 1996: 105.—K.K.P. Lim, 1996: 51.—R.C.H. Teo & Rajathurai, 1997: 383 (Bukit Timah [BTNR]).—Chan-ard et al., 1999: 35.— Iskandar & Colijn, 2001: 79.—K.P. Lim & F.L.K. Lim, 2002: 146.— Fry et al., 2003b: 2050. Zoacys [sic] carinatus —L.M. Chou, 1995: 148. Zaocys carinata — Manthey & Grossmann, 1997: 402. Ptyas carinata — Cox et al., 1998: 55.—N. Baker & K.P. Lim, 2008: 107, 161.— Das, 2010: 298.—L.L. Grismer, 2011a: 211.—P.K.L. Ng et al., 2011: 273.—N. Baker & K.P. Lim, 2012: 107, 161.— Das, 2012a: 63.—Wallach et al., 2014: 615.—Chan-ard et al., 2015: 171.— de Lang, 2017: 181.— Das, 2018: 74.—R.C.H. Teo & Thomas, 2019: 164, 181 (Bukit Timah Nature Reserve).— Charlton, 2020: 190–191 (Dairy Farm Nature Park).— Dubois & David, 2020: 112.—C.C. Ong & C. Yeong, 2020: 145 (Thomson Nature Park). Remarks. From early on, the occurrence of P. carinata in Singapore was known only from Boulenger (1893) who first reported it based on a specimen deposited at NHMUK collected by Dennys, and by Hanitsch (1898) who noted that this species is represented in the the Raffles Museum collection. However, the LKCNHM only has specimens from 1899, 1922, 1926, 1933, 1986, 1987, and two from 2008. After Hanitsch (1898), P. carinata was only next reported 90 years later (Table 2) from a live specimen detected at SRF on 26 June 1988 (Lim & Lim 1988a). That same year, another was seen at Singapore Zoo on 6 September 1988 (Lim & Lim 1988b), and on Mandai Lake Road on 23 December 1988 (Lim & Lim 1988c). Subsequent observations include a mating pair at BTNR on 12 February 1989 (Lim & Lim 1989), two seen at NSSF and SRF (Lim 1990a), two seen at BTNR and RRR (Lim 1993a), one observed eating a D. caudolineatus at MNF on 8 May 1994 (Subaraj et al. 1995), a roadkill at BTNR on October 1995 (Lim 1995), and Teo & Rajathurai (1997) noted a total of 21 records during their survey, some which likely include the antecedent records. Nowadays, P. carinata is considered common (Teo & Rajathurai 1997; Baker & Lim 2012), but surprisingly, no current records have been reported aside from one seen at BTNR (Teo & Thomas 2019) and one observed eating an O. octolineatus at TNP on 6 July 2020 (Ong & Yeong 2020). LKCNHM has two specimens from 2008, Charlton (2020) published a photograph of one from DFNP, and the individual in Figure 19H was seen at Mandai Track 15 on 21 October 2018 (I.S. Law pers. comm.). Occurrence. Restricted to CNR and surrounding Nature Parks and forests. Uncommon. Singapore conservation status. Vulnerable. Conservation priority. Highest. IUCN conservation status. Least Concern [2012]. LKCNHM & NHMUK Museum specimens. Singapore (no locality): BMNH 1880.9.10.2 (no date); Bukit Timah: ZRC.2.4555 (Feb-1922); Bukit Timah Nature Reserve: ZRC.2.6169 (no date); Hindhede Drive: ZRC.2.2305 (21-Feb-1986), ZRC.2.2306 (08-Oct-1987); Impounding [MacRitchie] Reservoir: ZRC.2.4551 (1899); Old Upper Thomson Road: ZRC.2.6735 (22-Jul-2008); Singapore Golf Club [SICC]: ZRC.2.4549 (21-Dec-1933); Thomson Road Reservoir [MR]: ZRC.2.4547 (May-1926); Upper Seletar Reservoir Road: ZRC.2.6713 (11-Jul-2008). Additional Singapore museum specimens. Singapore (no locality): AMNH. Singapore localities. Bukit Timah (not specified)—Bukit Timah Nature Reserve—Dairy Farm Nature Park— Hindhede Drive—MacRitchie North Forest—MacRitchie Reservoir—Mandai Lake Road—Mandai Track 15—Nee Soon Swamp Forest—Old Upper Thomson Road—Rifle Range Road—Sime Road Forest— Singapore Island Country Club— Singapore Zoo—Thomson Nature Park—Upper Seletar Reservoir Road.

Published as part of Figueroa, Alex, Low, Martyn E. Y. & Lim, Kelvin K. P., 2023, Singapore's herpetofauna: updated and annotated checklist, history, conservation, and distribution, pp. 1-378 in Zootaxa 5287 (1) on pages 172-173, DOI: 10.11646/zootaxa.5287.1.1, http://zenodo.org/record/7960319