Crotalus tlaloci BRYSON, LINKEM, DORCAS, LATHROP, JONES, ALVARADO-DÍAZ, GRÜNWALD & MURPHY, 2014
Can you confirm these amateur observations of Crotalus tlaloci?
|Higher Taxa||Viperidae, Crotalinae, Colubroidea, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Crotalus tlaloci BRYSON, LINKEM, DORCAS, LATHROP, JONES, ALVARADO-DÍAZ, GRÜNWALD & MURPHY 2014: 483|
Crotalus triseriatus triseriatus — CAMPBELL & LAMAR 2004: 527 (part.)
Crotalus triseriatus triseriatus — FLORES-VILLELA & HERNÁNDEZ-GARCÍA 1989: 16
Crotalus triseriatus triseriatus — PÉREZ-RAMOS et al. 2000: 34
Crotalus triseriatus triseriatus — FLORES-VILLELA & HERNÁNDEZ-GARCÍA 2006: 270
|Distribution||Mexico (Guerrero, Estado de México, Michoacán, Morelos, possibly W Puebla)|
Type locality: “Los Llanos” (18°36’N, 99°37’W; 2200–2300 m above sea level; asl hereafter), 10 km by road from Taxco to Tetipac, Sierra de Taxco, municipality of Tetipac, state of Guerrero, Mexico
|Types||Holotype: MZFC 3666, adult female, collected 20 June 1986 by Efrain Hernández-García. Paratypes. 11 specimens. MEXICO: GUERRERO: Cerro del Huizteco, Sierra de Taxco, municipality of Taxco (18°36'N, 99°36'W; 2300–2520 m asl); collected 22–23 August 1986 by E. Hernández-García (MZFC 3664–3665). “Arroyo las Damas”, Sierra de Taxco, municipality of Tetipac (18°38'N, 99°37'W; 1600–1850 m asl); collected by E. Hernández-García (MZFC 3666). ESTADO DE MÉXICO: Acatitlán, municipality of Valle de Bravo; collected 7 September 1988 by T. Hentschel-Maida (MZFC 4324). Los Álamos, municipality of Valle de Bravo (19°11'20.2"N, 100°03'57.2"; 2201 m asl; NAD27 Mexico); collected 23 May 2008 by J. Jones, C. I. Grünwald, and R. W. Bryson Jr. (HINIRENA 725–726). Los Álamos, municipality of Valle de Bravo (19°11'20.2"N, 100°03'57.2"; 2201 m asl; NAD27 Mexico); collected 22 July 2009 by R. W. Bryson Jr. and M. Torocco (MZFC 25114–25115). MORELOS: Km 12, Carr. Cuernavaca-Ocuilán, municipality of Cuernavaca; collected 17 March 1990 by M. Torres Chávez (MZFC 4657). Carr. Cuernavaca-Ocuilán, near state border, municipality of Cuernavaca (18°58'54.43"N, 99°18'20.43"W; 2268 m asl; WGS84); collected 13 June 2009 by J. Jones, C. I. Grünwald, and R. W. Bryson Jr. (MZFC 25111). MICHOACÁN: N Arroyo Seco, municipality of Aporo (19°40'28.3"N, 100°22'35.8"W; 2463 m asl; NAD27 Mexico); collected 24 May 2008 by J. Jones, C. I. Grünwald, and R. W. Bryson Jr. (HINIRENA 724).|
|Diagnosis||Diagnosis. Crotalus tlaloci can be distinguished from all members of the C. triseriatus species group by the combination of the following characters: (1) presence of intercanthals, (2) undivided upper preocular, (3) 152–164 ventrals in males, 156–165 in females, (4) 27–33 subcaudals in males, 22–32 in females, (5) small rattle (proximal rattle width 11.1–14.5% of head length), (6) long tail (8.9–11.3% of total body length in males, 8.0–10.7% in females), (7) usually two pairs of symmetrical, similarly sized intercanthals, and (8) dark postocular stripe that noticeably narrows before reaching the posterior of the eye.|
Crotalus tlaloci is most similar to species of the C. triseriatus group distributed along the Trans-Mexican Volcanic Belt. Crotalus tlaloci is distinguished from these species by the presence of intercanthals (lacking in C. pusillus), undivided upper preocular (divided 14.3% of the time in C. armstrongi and 9.4% of the time in C. triseriatus), high number of ventrals (overlapping with C. pusillus, but mean number in C. tlaloci higher than C. pusillus: 156 vs. 154, respectively), high number of subcaudals (mean number in females higher than in C. pusillus, C. armstrongi, and C. triseriatus: 28 vs. 26, 24, and 24; in males, higher than in C. armstrongi and C. triseriatus: 30 vs. 28 in both), proportionately small proximal rattle (mean width smaller than in C. armstrongi and C. triseriatus: 12.8% of head length vs. 14.0% and 15.8%), and proportionately longer tail (mean length in females higher than in C. pusillus, C. armstrongi, and C. triseriatus: 9.2% of total length vs. 8.6%, 8.3%, and 8.3%). Most specimens (10/12) possess two pairs of symmetrical, similarly sized intercanthals, creating the appearance of butterfly wings. Of the 100 specimens in the C. triseriatus group that we examined, this symmetrical paired arrangement of intercanthal scales in the prefrontal region (“butterfly wings”) was observed in only one other specimen (C. armstrongi, CNAR 4498). Crotalus tlaloci also possess a dark postocular stripe that noticeably narrows before reaching the posterior of the eye. In C. pusillus, C. armstrongi, and C. triseriatus, the postocular stripe is generally of uniform width, although on rare occasions in C. pusillus and C. armstrongi it tapers slightly before reaching the eye.
|Comment||Habitat: open areas in cloud forest and humid oak-pine forest.|
|Etymology||This species is named for Tláloc, the Aztec god of rain.|