Dipsas vagus (JAN, 1863)
Can you confirm these amateur observations of Dipsas vagus?
|Higher Taxa||Colubridae (Dipsadinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Jan's Tree Snake|
|Synonym||Leptognathus vagus JAN 1863: 100|
Leptognathus vaga — COPE 1868: 136
Pareas vagus — BOETTGER 1888: 145.
Pseudopareas vagus — BOULENGER 1896: 462
Pseudopareas vagus — WERNER 1922: 200
Pseudopareas vagus — DUNN 1923: 187
Pseudopareas vagus vagus — AMARAL ‘‘1929’’a : 33
Pseudopareas vagus vagus — AMARAL ‘‘1929’’b : 201
Pseudopareas vagus vagus — AMARAL ‘‘1929’’c : 75
Sibynomorphus vagus — PETERS 1960: 164
Sibynomorphus vagus — LEHR et al. 2002
Sibynomorphus vagus — CADLE 2007
Sibynomorphus vagus — WALLACH et al. 2014: 671
Dipsas vagus — ARTEAGA et al. 2018
|Distribution||Peru (Piura: Huancabamba), elevation 1,810 to 1,920 m.|
Type locality: Hong Kong (designated as South America by Dunn 1923: 187)
|Types||Holotype: MSNM (Museo Civico di Storia Naturale, Milan) (probably destroyed during the bombing of 1943).|
|Diagnosis||Diagnosis in Cadle 2007.|
|Comment||Synonymy that of PETERS & OREJAS-MIRANDA 1970|
The holotype of Sibynomorphus vagus, illustrated by Jan and Sordelli (1860–1881) (Fig. 34), was a specimen in Milan’s Museo Civico di Storia Naturale. Jan’s (1863: 100– 101) diagnosis of Leptognathus vagus appeared in a key to the genus, in which L. vagus was diagnosed by the following characteristics:  scale rows, loreal in contact with the eye, and 8 supralabials. Jan and Sordelli’s (1860–1881) illustration of the holotype shows the following character i s t i cs : body s l i ght l y compr es s ed; smooth dorsal scales in 15 rows anteriorly and at midbody; supralabials 8 with 4–5 touching the eye on each side, 2–4 bordering the loreal; infralabials 10/10, the ﬁrst pair in contact behind the mental; three pairs of polygonal chin shields (the ﬁrst pair somewhat elongate) followed by three preventrals (the ﬁrst with a partial suture); loreal and preocular bordering the anterior edge of the eye (preocular superior to loreal); loreal longer than tall; postoculars 2/2; primary temporals 1/1, secondary temporals 2/2, tertiary temporals 2/2 (with the upper secondary temporal fused with the upper tertiary temporal on the left side); anal single; subcaudals 50. The anterior body has a series of irregular lateral vertical markings one scale row or less in width and separated by 2–3 rows. Middorsally is a series of smaller irregular ﬂecks that are aligned with or slightly off- set from the lateral series. Top of the head without distinct pattern (stippled uniformly); a slight concentration of dark pigment is on suture lines of the posterior supra- labials. The ventrals and subcaudals are heavily patterned with bold half-moon markings; on the posterior body, these tend to align into longitudinal rows on the outer portion of the ventrals [from CADLE 2007].
Diet: primarily molluscs (T. de Lema, pers. comm., 16 Oct 2015).
Habitat: fully arboreal (Harrington et al. 2018).
|Etymology||The common meaning of the speciﬁc epithet, vagus, is wandering or roaming. However, the word can also mean diffuse or indeﬁnite (as in vague). Cadle (2007) suspects that this is a reference to the diffuse dorsal pattern of Sibynomorphus vagus compared with other species of Leptognathus known at the time of its description—as seen especially by comparing the illustration of S. vagus with the other species illustrated on the same plate by Jan and Sordelli (1860–1881): Dipsas incerta, S. mikanii, and the Asian colubrid Pareas laevis (all in the genus Leptognathus at the time); these are much more boldly marked than S. vagus.|