Micrurus diutius (BURGER, 1955)
Can you confirm these amateur observations of Micrurus diutius?
|Higher Taxa||Elapidae, Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Trinidad Ribbon Coral Snake|
S: Coral Acintada Trinitaria
S: Cobra Coral de Faixas de Trinidad
|Synonym||Micrurus lemniscatus diutius BURGER 1955|
Micrurus lemniscatus diutius — GASC & RODRIGUES 1980
Micrurus lemniscatus diutius — WELCH 1994: 85
Micrurus lemniscatus diutus [sic] — STARACE 1998: 361
Micrurus lemniscatus diutius — GORZULA & SEÑARIS 1999
Micrurus lemniscatus diutius — BARRIO-AMOROS et al. 2003
Micrurus lemniscatus diutius — FROTA et al. 2005
Micrurus lemniscatus diutius — FEITOSA et al. 2007
Micrurus diutius — STARACE 2013: 502
Micrurus diutius — JOWERS et al. 2019
Micrurus diutius — NOGUEIRA et al. 2019
Micrurus diutius — PIRES et al. 2021: 69
|Distribution||Trinidad, E Venezuela (incl. Carabobo), C Guianas / Guyana, Brazil (Roraima, Amapá, Amazônas, Pará fide Costa & Bérnils 2018; Nogueira et al., 2019)|
Type locality: “Tunapuna, Trinidad”
|Types||Holotype: FMNH 34472, male; paratypes: Carnegie Museum 7925 (from Cumanacoa, Sucre, Venezuela) and INHS (= UIMNH) 22626, adult male, from Hoso Rora, near Morawhanna, Northeast District, British Guiana|
|Diagnosis||Diagnosis. Micrurus diutius can be distinguished from all other triadal species of Micrurus by the following combination of morphological characters: black snout (rostral, internasals, anterior border of prefrontals, most of nasals, and 1–2 supralabials); white preocular transverse band covers most of prefrontals, anterior border of supraoculars, most of preoculars, and 1–2 supralabials; black cephalic cap includes most of frontal, supraoculars, postoculars, anterior 1⁄3 of parietals, 1⁄3–1⁄2 of temporals, and 2–3 supralabials; remainder of the head red, with or without black-tipped scales; venter of head red; irregular black markings on gulars, and infralabials highly variable; 1st triad separated from parietals by 2–7 scales; middle black ring slightly longer or same length as outer ones; white rings usually shorter than outer black rings; red rings shorter than entire triad or even middle black ring; red and white rings usually black-tipped, but with tendency to a less melanic pattern (Fig. 43C); and 6–16 body triads and 1 1⁄3 –12⁄3 tail triads (Pires et al. 2021: 69).|
Comparison with sympatric species. Micrurus diutius occurs sympatrically with Leptomicrurus collaris, four species of monadal Micrurus (M. averyi, M. pacaraimae, M. paraensis, and M. psyches) and eight triadal species (M. filiformis, M. hemprichii, M. isozonus, M. lemniscatus, M. obscurus, M. nattereri, M. spixii, and M. surinamensis). Micrurus diutius can be distinguished from L. collaris by the contact of the anteriormost infralabials behind the mental scale, and a triadal pattern (vs. the 1st infralabials separated by contact between the mental and anterior chin shields, and the bicolored pattern with incomplete rings). It differs from M. averyi, M. pacaraimae, M. paraensis, and M. psyches by the presence of a triadal pattern (vs. a monadal pattern); from M. filiformis by the number of ventrals (214–242 vs. 259–335), the number of body triads (6–15 vs. 12–23), and the number of white rings on the triads (2–5 vs. 1–2); from M. lemniscatus by a lower mean number of ventrals (227.6 vs. 245.8), a higher number of vertebral scales between the parietals and the first triad (2–4 vs. 6–8), and longer white rings on the triads (2.5–5 vs. 1.5–2); and from M. hemprichii, M. isozonus, M. spixii, M. obscurus, M. nattereri, and M. surinamensis by the presence of a white preocular transverse band (vs. the absence of a white preocular transverse band) (Pires et al. 2021: 70).
Variation. The head is red and might contain irregular black markings, black-tipped scales, or both. A white transverse band and a black cephalic cap are variable in length. The black cephalic cap usually reaches the anterior 2⁄3 (57.6%), 1⁄2 of the parietals (26.4%), or the anterior 1⁄3 (6.9%), but rarely reaches the entire parietals (9%). Ventrally, the chin contains irregular black markings that include the mental and most or all of the infralabials, in a typical horseshoe-shaped pattern (86.4%). Other patterns may include irregular semicircles (8.5%), black posterior infralabials (2.2%), black anterior gulars (1.4%), and other aberrant forms (1.5%) (Fig. 49). In males (N = 301), the ventrals = 186–270, the subcaudals = 20–41, and the body triads = 7–18; the HL = 7.9–38.0 mm, the SVL = 210–1,550 mm, and the TL = 12.8–100.9 mm. In females (N = 132), the ventrals = 210–276, the subcaudals = 21–40, and the body triads = 9–16; the HL = 8.0–34.3 mm, the SVL = 96–1,274 mm, and the TL = 13.1–85.7 mm. The 1st triad is separated from the parietals by 2–5 vertebral scales: 3 (54%), 4 (31%), 2 (11%), and 5 (4%). The black middle triad rings might be longer than the outer rings (84.8%), or all three might be semi-equal in length (15.2%). The white rings vary in length (1⁄2–3 dorsal scales) with the majority (84.5%) consisting of 11⁄2 (33.8%), 2 (30.4), and 21⁄2 (20.3%)
scales. The tail triads are 1–2, with a predominance of the 12⁄3 pattern (12⁄3 = 50%; 1 1⁄3 = 30.6%; 2 = 16.2%; 1= 3.2%). The degree of black pigmentation on the red rings is variable and can be irregular (86%), with all the scales containing black tipping (7.3%) or immaculate (6.7%). Similarly, the white rings can be irregular and marked with black (31.3%), immaculate (22%), or the scales might contain fine black tipping (46.7%) (Pires et al. 2021: 70).
Diagnosis (obsolete). Differs from the typical subspecies in having the white rings densely spotted with black above and the red rings moderately spotted; in having fewer ventrals, 219 — 226 in males, 226 — 239 in females (Table 1); and, perhaps, in reaching a larger size (Table 5). To distinguish the species lemniscatus from other coral snakes with which it is associated in Venezuela, the Guianas or Trinidad, reference may be made to the key in Burger 1955.
|Comment||Synonymy: Wallach et al. 2014: 448 listed this species as synonym of Micrurus lemniscatus.|
|Etymology||From the latin “diutius”, meanning too long. From the point of view of potential victims, a meter-long venomous snake is certainly too long (Burger 1955: 40).|