Paroplocephalus atriceps (STORR, 1980)
Can you confirm these amateur observations of Paroplocephalus atriceps?
|Higher Taxa||Elapidae (Hydrophiinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Lake Cronin Snake|
|Synonym||Brachyaspis atriceps STORR 1980|
Notechis atriceps — STORR 1982
Echiopsis atriceps — COGGER 1983
Denisonia atriceps — STORR 1984
Suta atriceps — GOLAY et al. 1993
Echiopsis atriceps — COGGER 2000: 649
Paroplocephalus atriceps — KEOGH et al. 2000
Paroplocephalus atriceps — WILSON & SWAN 2010: 494
Paroplocephalus atriceps — WALLACH et al. 2014: 538
|Distribution||Australia (Western Australia)|
Type locality: open eucalypt woodland on sandy loam at Lake Cronin, Western Australia, in 32°23'S, 119°45'E.
|Types||Holotype: WAM R67330|
|Diagnosis||Diagnosis: A small elapid snake with large black head; large, somewhat obtrusive eyes; narrow neck; 19 scale rows at midbody; anal and subcaudals single. Further distinguishable from B. curta (Schlegel) by head parallel-sided in plan (rather than widest at rear, from which it steadily narrows towards pointed snout), fewer temporals, longer tail, more numerous ventrals and subcaudals, and iris entirely golden orange (rather than uppermost sector only). Further distinguishable from Denisonia suta (Peters) by lack of pale stripe through eye, longer tail and more numerous subcaudals.|
Diagnosis. A monotypic genus containing P. atriceps, a terrestrial hydrophiine elapid snake with anal and all subcaudals undivided; dorsal scales smooth but not highly glossed; head moderately broad and distinct from neck; eye large, pupil round; 3 noncanaliculate maxillary teeth behind diastema; temporal scales 2 + 2 + 3 (N 7), 2 + 2 + 4 (N 8), 2 + 3 + 4 (N 1) and 2 + 3 + 5 (N 1) (formula follows definition in Scanlon, 2000); preocular without canthus rostralis, contacts undivided nasal and 2nd supralabial; 6 supralabials (41%), or 7 (59%) when temporolabial (lower anterior temporal) reaches lip between 5th and last; parietal separated from lower postocular; 7 infralabials. ‘Oxyuranus type’ of venom-gland musculature (sensu McDowell, 1967; main dorsal portion of m. adductor externus medialis reaching transverse crest of supraoccipital and overlapping anterior part of m. depressor mandibulae, but not attaching to quadrate). Neck and posterior trunk slender, and body somewhat laterally compressed; ventral scales extend to lower lateral surface of body, and their posterior edges arcuate (lateral parts concave; see Ehmann, 1993). Scale rows 21–23 at first ventral, sometimes reducing to 17 on neck, 17 (N 2) or 19 (N 15) at midbody; two or three reductions, (17–15–13) or (19–17–15–13) respectively posterior to midbody, sometimes increasing again to 15 rows at or just before last ventral. Ventrals 171–190 (N 17, mean 180), males 171–183 (N 12, mean 178.1), females 180–190 (N 5, mean 184.8). Subcaudals 41–52 (N 17, mean 47), males 44–52 (N 12, mean 48.1), females 40–48 (N 5, mean 42.8). Upper iris pale, reducing to a narrow pale band bordering remainder of pupil (golden orange in life: Storr,  – see Figure 1B this study); body reddish brown, olive green (in eastern part of range), or blackish brown; head dull black or dark grey with pale spots on upper and lower labials, and denser black collar on neck, pale-edged posteriorly; dorsal bands or blotches absent (Figure 7); oral lining pale, tongue dark. Largest live specimen is a female (currently kept at Snakes Harmful & Harmless) with snout-vent length (SVL) 730 mm, undamaged tail length 90 mm (12.3% SVL vs. 16.1% in WAM R132047, a female examined by Keogh et al. 2000); the largest male (WAM R151290) has SVL 530 mm, tail 99 mm (18.7%). Presumed to be viviparous, but reproduction and natural diet unknown apart from a single prey record of an agamid lizard.
Most like Hoplocephalus spp. in body form and scalation (also cranial morphology, Keogh et al. 2000); distinguished by lower number of ventrals (171–190 vs. 190–250) and usually of subcaudals (41–52 vs 40–70), lower number of midbody scale rows (17–19 vs 19–21), only weakly angled and scalloped ventral scales (vs usually distinctly keeled and notched as an adaptation for climbing). Distribution restricted to arid eucalypt woodlands of Western Australia (Figure 2) v east coast, hinterland and arid eucalypt woodlands of New South Wales and Queensland (from Bush 2017).
Type species: Brachyaspis atriceps STORR 1980 is the type species of the genus Paroplocephalus KEOGH et al. 2000.
Habitat: arboreal (Bush 2017).
|Etymology||Named after its color, Latin “ater, atra, atrum” = dark or black, and “-ceps”, a short form of “caput” = head.|