You are here » home advanced search search results Thamnophis foxi

Thamnophis foxi ROSSMAN & BLANEY, 1968

Can you confirm these amateur observations of Thamnophis foxi?

Add your own observation of
Thamnophis foxi »

We have no photos, try to find some by Google images search: Google images

Higher TaxaColubridae (Natricinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)
Common NamesE: Fox's Mountain Meadow Snake
S: Pradera de Fox 
SynonymAdelophis foxi ROSSMAN & BLANEY 1968
Adelophis foxi — ROSSMAN & WALLACH 1987
Adelophis foxi — LINER 1994
Adelophis foxi — DE QUEIROZ et al. 2002
Adelophis foxi — WALLACH et al. 2014: 8
Thamnophis foxi — HALLAS et al. 2021
Thamnophis foxi — NUÑEZ et al. 2023 
DistributionMexico (Durango)

Type locality: "from a meadow in pine forest (8,600 feet) 1/4 mi. E Mil Diez (approx. 2 mi. W El Salto), Durango, México."  
TypesHolotype: LSUM 14330, a 419 mm female (D.A. Rossman and R.M. Blaney, 16 July 1966). 
DiagnosisDiagnosis: A species of natricine snake distinguished from its sole congener, Adelophis copei Dugès, by possessing 17-17-17 dorsal scale rows (15-15-15 in copei), a semidivided nasal (entirely divided in 6 of 8 cases in copei), a discrete loreal scale (fused with prefrontal in copei), longer anterior than posterior genials (posterior longer in copei), 4th and 5th supralabials of nearly equal size (5th equal to combined length of 2nd, 3rd, and 4th in copei), six infralabials (five in copei), two posterior tem porals (one in copei), a proportionately longer muzzle (frontal only 28.3 to 28.6 per cent longer than muzzle1 in male foxi, 37.2 to 51.7 per cent longer in male copei?), a proportionately longer tail (23.4 to 25.6 per cent of total length in adult male foxi, 19.8 to 21.0 per cent in male copei), 20 or 21 maxillary teeth (23 of 24 in copei), a pair of dark paravertebral stripes (lacking in copei), and no light lateral stripe (present in copei). The combined characteristics of an undivided anal plate and no dorsal scale row reduction readily distinguish the genus Adelophis from all other New World natricines. (Rossman & Blaney 1968)

DEFINITION (foxi). The larger member of the genus Adelophis, characterized by: 17 -17 -17 dorsal scale rows; presence of a loreal; two posterior temporals; 4th and 5th supralabials subequal in size; 132-137 ventrals in females, 133-139 in males; 48-57 subcaudals in females, 52-64 in males; tail 21-23% of total length in females, 21.5-25.5% in males; dorsal pattern with 1 pale stripe and 4 dark stripes on a grayish brown or olive brown ground color; 20-21 maxillary teeth. (Rossman & Wallach 1987)

Description of holotype. Dorsal scales in 17 rows throughout, keeled except for those in row 1, which are smooth and enlarged (those in row 2 are weakly keeled and slightly enlarged); ventrals 132; subcaudals 51 ; anal entire. Supralabials 5, third and fourth entering orbit; infralabials 6, 4 in contact with anterior genials, which are longer than posterior genials (A/P= 1.168); nasal semidivided, suture below naris; loreal rectangular; preocular single; postoculars 2 on left, 1 on right; temporals 1+2. Scales on top of head normal; internasal suture 77.4 per cent length of prefrontal suture; frontal 20.3 per cent longer than muzzle, and 31 per cent shorter than parietals. Total length 419 mm, tail length 90.5 (21.6 per cent of total length). (Rossman & Blaney 1968)

Teeth: Maxilla with 20 moderately slender, slightly recurved teeth, decreasing slightly in size posteriorly (anteriormost 3 or 4 also smaller). Ten teeth lie anterior to the prefrontal process. (Rossman & Blaney 1968)

Coloration: Ventrolateral stripe and dorsal scale rows 1, 2, and 3 oakbuff (Maerz and Paul 13D7) in living animal. Row 4 and rows 7 and 8 coffee (15A11), with black pigment on anterior half of each scale, giving impression of dark lateral stripe and paravertebral stripe. Rows 5 and 6 gray stone (13A2), keels coffee. Vertebral row gray (13A1) with yellow pigment at anterior end of each scale. Center and posterior edge of ventral scales corn yellow (10J5) overlaid with buff (12J5). (Rossman & Blaney 1968)

Variation. Coloration of adult paratypes differs from that of holotype primarily in being lighter and brighter (see Figure 1). The anterior end of each scale in rows 1 and 2 of an adult female paratype (LSUMZ 14326) was touched with orange in life. The newly born young have a pattern similar to that of the adults, but in life the coloration is duller (in large part because of the total lack of any yellow or orange pigment) and the dark stripes are less distinct (because of less extensive distribution of the black pigment). The venter appears dull white. In preservative the original epidermal scales slough off easily in both adults and juveniles leaving a uniformly grey dorsum, save for the light and dark stripes. Variation in those characters that show sexual dimorphism or ontogenetic variation is summarized in Table 1. Males tend to have a longer tail, more subcaudals, a longer head, and a shorter muzzle than the females. Larger series of adults probably will reveal that males also have more ventrals and do not attain as great a length as females. Proportional tail length increases ontogenetically, juvenile males having the tail only about as long propor tionately as in adult females. The marked differences between juvenile and adult females in ventral and subcaudal number probably is attributable to the small size of the sample. One juvenile (LSUMZ 14328) is aberrant in several respects: half scutes are present at ventrals 106, 131, and 134; subcaudals 3, 4, 45, 46, and 47 are single; an extra row of dorsal scales appears irregularly between tows 3 and 4 (giving a maximum count of 19), finally dropping out at the level of ventral 71 on the right and 84 on the left; the tail is unusually short for a male, which is reflected by both a low tail length/total length value and a low number of subcaudals (only 1 of the 6 females has fewer). One of the adults (LSUMZ 16411) also has half scutes, all on the left side of the venter (at V 14, 26, 67, and 132). (Rossman & Blaney 1968) 
CommentAdelophis foxi and its congener, A. copei, share several morphological characteristics not seen in Thamnophis, including the presence of only five supralabial scales (vs six or more in all Thamnophis) and a lack of reduction in dorsal scale row numbers posteriorly. In addition, both species of Adelophis have striping patterns unlike those of any Thamnophis, although they also differ from each other in this respect (Rossman and Blaney, 1968). However, all of these traits can be interpreted as autapomorphies of Adelophis as a whole or of A. foxi and A. copei individually. If this is the case, these traits would have no bearing on the relationships of Adelophis to other taxa. Interestingly, both species of Adelophis possess the one obvious morphological synapomorphy for Thamnophis, an undivided anal plate (Rossman and Blaney, 1968). Interestingly, Adelophis foxi is nested within Thamnophis by DNA analysis (De QUEIROZ et al. 2002, Hallas et al. 2021). 
EtymologyNamed after Dr. Wade Fox Jr. (1920-1964), zoologist and herpetologist at the University of California, Berkeley until he died from a heart attack. 
  • Beolens, Bo; Michael Watkins, and Michael Grayson 2011. The Eponym Dictionary of Reptiles. Johns Hopkins University Press, Baltimore, USA - get paper here
  • Burbrink FT, Futterman I. 2019. Female‐ biased gape and body-size dimorphism in the New World watersnakes (tribe: Thamnophiini) oppose predictions from Rensch's rule. Ecol Evol. 00:1–10
  • HALLAS, JOSHUA M.; THOMAS L. PARCHMAN & CHRIS R. FELDMAN. 2021. Phylogenomic analyses resolve relationships among garter snakes (Thamnophis: Natricinae: Colubridae) and elucidate biogeographic history and morphological evolution. Molecular Phylogenetics and Evolution 107374. [2022 in print] - get paper here
  • Heimes, P. 2016. Snakes of Mexico. Chimaira, Frankfurt, 572 pp
  • Lemos-Espinal JA, Smith GR, Gadsden-Esparza H, Valdez-Lares R, Woolrich-Piña GA 2018. Amphibians and reptiles of the state of Durango, Mexico, with comparisons with adjoining states. ZooKeys 748: 65-87 - get paper here
  • Nuñez, L.P., Gray, L.N., Weisrock, D.W., Burbrink, F.T., 2023. The Phylogenomic and Biogeographic History of the Gartersnakes, Watersnakes, and Allies (Natricidae: Thamnophiini). Molecular Phylogenetics and Evolution - get paper here
  • Queiroz, Alan de; Robin Lawson and Julio A. Lemos-Espinal 2002. Phylogenetic Relationships of North American Garter Snakes (Thamnophis) Based on Four Mitochondrial Genes: How Much DNA Sequence Is Enough? Molecular Phylogenetics and Evolution 22: 315-329 - get paper here
  • Rossman D A; Wallach V 1987. Adelophis Duges. Mountain meadow snakes. Catalogue of American Amphibians and Reptiles ( 408: 1-2 - get paper here
  • Rossman, Douglas A. & Blaney, R. M. 1968. A new Natricine snake of the genus Adelophis from western Mexico. Occasional papers of the Museum of Zoology, Louisiana State University (35): 1-12 - get paper here
  • Valdez-Lares, R.; R. Muñiz-Martínez; E.Gadsden; G. Aguirre-León; G. Castañeda-Gaytán; R. Gonzalez-Trápaga 2013. Checklist of amphibians and reptiles of the state of Durango, México. Check List 9 (4):714-724 - get paper here
  • Wallach, Van; Kenneth L. Williams , Jeff Boundy 2014. Snakes of the World: A Catalogue of Living and Extinct Species. [type catalogue] Taylor and Francis, CRC Press, 1237 pp.
  • Webb, R.G. 1984. Herpetogeography in the Mazatlán-Durango Region of the Sierra Madre Occidental, Mexico. Vetrebrate Ecology and Systematics - A ribute to Henry S. Fitch; Museum of Natural History, University of Kansas, Lawrence, pp. 217-241
External links  
Is it interesting? Share with others:

As link to this species use URL address:

without field 'search_param'. Field 'search_param' is used for browsing search result.

Please submit feedback about this entry to the curator