Anilios systenos ELLIS & DOUGHTY, 2017
Can you confirm these amateur observations of Anilios systenos?
|Higher Taxa||Typhlopidae (Asiatyphlopinae), Typhlopoidea, Serpentes, Squamata (snakes)|
|Common Names||E: Sharp-snouted Blindsnake|
|Synonym||Anilios systenos ELLIS & DOUGHTY in ELLIS et al. 2017|
Anilios systenos — TIATRAGUL et la. 2023
|Distribution||Australia (Western Australia)|
Type locality: 15 km east of Geraldton (28°46'S; 114°37'E), Western Australia.
|Types||Holotype: WAM R114892, subadult male collected in 1992 by T. Backshall. Paratypes (3). WAM R1734, Newmarracarra, 21 km east of Geraldton (28°43'S; 114°49'E); WAM R113398, locality and collection data unknown; WAM R114893, 15 km east of Geraldton (28°46'S; 114°37'E), Western Australia.|
|Diagnosis||Diagnosis: A moderately long, slender Anilios to about 270 mm total length. Distinguished from all other Anilios by a combination of midbody scales in 18 rows, dorsal body scales 598–621, snout bluntly angular in profile, tapering to a rounded point, snout tapering to a narrow rounded edge with faint trilobed appearance in dorsal view, hardened anterior rostral edge extending slightly ventrally to form a weak hook, nasal cleft originating from second supralabial, extending anteriorly to reach nostril and terminating at rostral scale, presence of a terminal tail spine, colouration pale with dorsum slightly darker than ventrum and lack of any black pigment on head, body or tail.|
Comparison with other species. Anilios systenos sp. nov. can be distinguished from 33 of the 45 described Anilios species by the number of midbody scale rows (18 vs 16, 20, 22 and 24), which does not vary within any Anilios species. Of the 11 Anilios species that also possess 18 MBSR (i.e. A. affinis, A. aspina, A. chamodracaena, A. grypus, A. guentheri, A. howi, A. margaretae, A. micromma, A. obtusifrons sp. nov., A. yampiensis and A. zonula), A. systenos sp. nov. can be distinguished based on the shape of the head in dorsal view, faintly trilobed and tapering to a rounded point anterior to rostral-nasal suture (vs bluntly rounded or rounded in A. affinis, A. aspina, A. chamodracaena, A. guentheri, A. micromma, A. obtusifrons sp. nov. and A. zonula) and bluntly angular in profile (vs rounded in A. aspina, A. guentheri, A. howi, A. micromma, A. obtusifrons sp. nov., A. yampiensis and A. zonula), absence of a prominent hooked beak (vs present in A. grypus), ovate rostral scale not narrowing anteriorly until beyond the nasal scale (vs elliptical in A. aspina, A. guentheri and A. howi), higher number of DBS (<560 in A. aspina, A. chamodracaena, A. howi, A. margaretae, A. micromma, A. yampiensis and A. zonula), origin of nasal cleft from second supralabial (vs preocular in A. yampiensis; first or preocular in A. grypus), termination of nasal cleft at rostral scale dividing nasal scale (vs not divided in A. aspina, A. chamodracaena, A. grypus, A. guentheri, A. margaretae and A. obtusifrons sp. nov.), nasal cleft not visible in dorsal view (vs visible for A. aspina and A. micromma), presence of a terminal tail spine (vs absent for A. aspina and A. zonula) and lack of any black colouration on head and/or tail (vs present for A. chamodracaena, A. grypus and A. guentheri).
Six species are known or considered to possibly occur in sympatry with the species: A. australis, A. grypus, A. hamatus, A. leptosoma, A. obtusifrons sp. nov. and A. waitii. It differs from A. australis by its slender appearance (vs thicker stout appearance of A. australis), fewer MBSR (18 vs 22), higher number of DBS (598–621 vs 278– 357); from A. grypus by the lack of a prominent hooked beak and lack of any black pigment on head or tail; from A. hamatus by fewer MBSR (18 vs 22), higher DBS (598–621 vs 330–396), and from A. waitii by fewer MBSR (18 vs 20) and snout not strongly trilobed (prominently trilobed in A. waitii).
Within its known distribution A. systenos sp. nov. is most similar in appearance to A. leptosoma and A. obtusifrons sp. nov. It differs from A. leptosoma by higher MBSR (18 vs 16) and a narrower and more pointed snout anterior to rostral-nasal suture in dorsal view. It differs from A. obtusifrons sp. nov. by greater number of DBS (598–621 vs 581–590), shape of snout in profile (tapering to a blunt point anterior to rostral-nasal suture vs bluntly rounded), presence of a hardened anterior and ventrally-facing rostral protrusion and termination point of nasal cleft (at rostral vs midway between nostril and rostral).
|Etymology||Derived from the Greek word systenos, meaning ‘tapering to a point’ in reference to the tapering appearance of the head and snout to a rounded point when viewed dorsally.|