Xenopeltis intermedius ORLOV, SNETKOV, ERMAKOV, NGUYEN & ANANJEVA, 2022
Can you confirm these amateur observations of Xenopeltis intermedius?
|Higher Taxa||Xenopeltidae, Henophidia, Pythonoidea, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Xenopeltis intermedius ORLOV, SNETKOV, ERMAKOV, NGUYEN & ANANJEVA 2022: 241|
|Distribution||Vietnam (Mang Canh)|
Type locality: Kon Plông, Kon Tum Province, Mang Canh Vietnam (14°41’25’’ N 108°19’31’’ E)
|Types||Holotype: ZISP 30354 (Figs. 2 – 4). Adult male, collected in May 2006 by N. L. Orlov at an elevation of 1250 m a.s.l.|
Paratypes (Figs. 5 – 7). Four specimens including two adult females ZISP 30355 and 30356 and two adult males ZISP 30357, 31660 collected in Kon Plông, Kon Tum Province, Mang Canh Vietnam in May 2006 by N. L. Orlov at elevations of 1150 – 1250 m a.s.l.
|Diagnosis||Diagnosis: Xenopeltis intermedius sp. nov. characterized by a combination of following characters: snout-vent up to 715 mm, tail length up to 65 mm; supraoculars — 2, preoculars 1; postoculars 1; suboculars 2; supralabilas formula 7 (3-2-2); infralabials — 7; no loreal; ventrals 174 – 185; subcaudal 16 – 22 pairs. These and other meristic and morphological differences listed in Tables 2 – 3. Skull elongated; lateral process of prefrontal short, only slightly protruding forward; parietal of less elongated shape than in X. unicolor; flat pentagonal surface in anterior part of parietal occupies significantly less than half of area of dorsal surface of parietal; from this surface a flat single ridge passes backward on midline of parietal, in observed specimens it bifurcates at the end; prominent basipterygoid processes strongly protruding from surface of basishenoid absent. Upper part of quadrate located above joint mandible wide and extends more backward than forward; lateral process on pterygoid in place of its articulation with ectopterygoid absent. (Orlov et al. 2022)|
Coloration in life. The coloration is even without patterns, the dorsal surface is beige — light brown or grayish brown, the ventral side is lighter, yellowishcream. Like all sunbeam snakes (Xenopeltidae), it has a highly iridescent scale surface (Fig. 4). (Orlov et al. 2022)
Comparisons. Xenopeltis intermedius sp. nov. differs from X. unicolor and X. hainanensis in a number of pholidosis characters and skeletal elements. X. unicolor (n = = 15) has 2 PtO, SupraLab 8 (3-2-3), ventrals 181 – 196, 26 – 31 Scd; X. hainanensis (n = 15) has 1 PtO, SupraLab formula 7 (3-2-2), ventrals 152 – 174 and subcaudals 16 – 19 pairs (Orlov, 2000), while X. intermedius (n = 5) has 1 PtO, SupraLab formula 7 (3-2-2), ventrals 174 – 185 and 16 – 22 pairs of Scd. Thus, from X. unicolor the new species differs in the presence of 1 PtO (2 PtO in X. unicolor) and the number of ventrals (174 – 185) and subcaudals (16 – 22), while X. unicolor has 181 – 196 ventrals and 26 – 31 pairs subcaudals. From X. hainanensis it differs by a higher (174 – 185) number of ventrals (152 – 174 in X. hainanensis) and slightly higher number of pairs of subcaudals (16 – 22 in X. intermedius and 16 – 19 in X. hainanensis). Both the shape and elongation of the head and the size of the eye are intermediate between X. unicolor with a more elongated and more flattened head, a more flattened body and larger eyes, and X. hainanensis with a shorter and less flattened head, more cylindrical body, smaller sunken eyes and broader subcaudals. If we compare the degree of adaptation of the body shape to a burrowing mode of life, then X. hainanensis shows the higher degree of adaptation for burrowing, X. intermedius sp. nov. occupies an intermediate position and X. unicolor is the least adapted.
In general, the skeleton of X. intermedius has some similarities with other species of this genus. By some cranial characters (short lateral process of prefrontal; wide quadrate projecting backward more than forward; sharp transition to surangular process on compound bone) X. intermedius is more similar to X. hainanensis than to X. unicolor. The skulls of X. hainanensis and X. intermedius are more compact, shorter, less cylindrical, and apparently have less kinetic ligaments. The skull of X. intermedius is less elongated than in X. unicolor and somewhat more elongated than in X. hainanensis. X. intermedius demonstrates differences in size, shape proportions and relief of the parietal bone from X. hainanensis and X. unicolor (Fig. 11). The shape of some bones in X. intermedius varies in the degree of its similarity to X. hainanensis and X. unicolor (nasals and to some degree supratemporals). The pterygoid is more similar to this bone in X. unicolor. Several characters of the dental system demonstrate an intermediate condition: 19 palatine and pterygoid teeth in X. intermedius vs. 15 – 16 in X. hainanensis and 21 – 22 in X. unicolor. In X. intermedius dental bears 18 teeth vsþ 11 – 13 in X. hainanensis and 25 – 26 in X. unicolor. The maxilla bears a smaller number of teeth (19) than in X. hainanensis (22 – 24) and X. unicolor (39 – 41). (Orlov et al. 2022)
|Etymology||The specific epithet intermedius is derived from Latin and refers to the intermediate state of morphological characters of the snake described herein.|