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| [Juvenile & Adult] Varanus tanimbar Weijola & Kraus, 2023 (photos by Valter Weijola, Richard How). |
ABSTRACT
We describe two new species of Varanus, one each endemic to the Louisiade and Tanimbar Archipelagos in Papua New Guinea and Indonesia, respectively. The new species belong to the subgenus Euprepiosaurus and, therein, to the widely distributed and relatively species-rich Varanus indicus group. They can be distinguished from all other recognised species by scalation, colour-pattern and genetic differences. The new species from Tanimbar is most closely related to V. indicus and V. melinus, from which it can be distinguished by its dark blue/grey tongue and higher middorsal and midventral scale counts. The new species from the Louisiades can be distinguished from its phylogenetically and geographically nearest relative, V. chlorostigma, by the presence of dorsal crossbands, the mostly pink tongue mottled with grey, and higher midbody scale count. The Louisiades constitute the easternmost archipelago of Milne Bay Province in eastern Papua New Guinea, and they host a diverse herpetofauna with a high degree of endemism; Varanus louisiadensis sp. nov. increases the known number of herpetofaunal endemics in that archipelago to 60. The Tanimbar Islands are situated in the southern part of Maluku Province (Moluccas), Indonesia, and are a minor centre of vertebrate endemism; Varanus tanimbar sp. nov. increases the number of known herpetofaunal endemics there to six.
KEYWORDS: Melanesia, Wallacea, endemic, reptile, lizard, taxonomy
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| The holotype (ZMUT Sa197) of Varanus louisiadensis sp. nov. on Misima Island (photo Valter Weijola). |
Varanus louisiadensis sp. nov.
Diagnosis: Varanus louisiadensis sp. nov. is a member of the subgenus Euprepiosaurus, which is defined by having the unique combination of an asymmetric sperm groove on the hemipenis and a laterally compressed tail (Ziegler et al. Citation2007). Molecular phylogenetic analyses place it within the V. indicus species group defined by the unilateral paryphasmata ornamentation of the hemipenis and lack of blue pigmentation on the tail (Ziegler et al. Citation2007; Weijola et al. Citation2019). It can be distinguished from all other species of Euprepiosaurus by its unique combination of: (1) dorsum black with more-or-less well-defined crossbands composed of yellow ocelli and/or dots, better defined in juveniles and subadults than adults; (2) tail black with distinct yellow bands, better defined in juveniles and subadults than adults; (3) tongue tines and a variable section of the mid-dorsal tongue surface dark grey, the remainder being pink; (4) pink-orange pigmentation usually present on cheeks and sides of neck; (5) venter pale yellow; (6) mid-body scale rows (S) 142–163; (7) mid-dorsal scale rows (XY) 139–169; (8) ventral scale rows (T) 101–113; (9) scales around neck (m) 101–118.
Etymology: The specific epithet refers to the Louisiade Archipelago of Milne Bay Province, Papua New Guinea, where this species is endemic.
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| Juvenile Varanus tanimbar sp. nov. caught by local hunters at Saumlaki, Yamdena (photo Valter Weijola). Adult V. tanimbar sp. nov. (WAM 109896) Lorulun, Yamdena Island (photo Richard How). |
Varanus tanimbar sp. nov.
Diagnosis: Varanus tanimbar sp. nov. is a member of the subgenus Euprepiosaurus, which is defined by having the unique combination of an asymmetric sperm groove and laterally compressed tail (Ziegler et al. Citation2007). Molecular phylogenetic analyses place it within the V. indicus species group defined by the unilateral paryphasmata ornamentation of the hemipenis and lack of blue pigmentation on the tail (Ziegler et al. Citation2007; Weijola et al. Citation2019). It can be distinguished from all other species of Euprepiosaurus by its unique combination of: (1) dorsum black with more or less well-defined crossbands composed of lemon-yellow ocelli and/or dots; (2) tail black with distinct yellow bands; (3) dorsal aspect of tongue blue-grey; (4) temporal region typically ornamented with a dark temporal band and a lemon-yellow postocular stripe; (5) venter pale yellow; (6) mid-body scale rows (S) 145–161; (7) mid-dorsal scale rows (XY) 159–170; (8) ventral scale rows (T) 107–109; (9) scales around neck (m) 109–119.
Etymology: The specific epithet tanimbar is a noun in apposition and refers to the Tanimbar Archipelago of Maluku, Indonesia, to which this species is endemic.
Valter Weijola and Fred Kraus. 2023. Two New Species of Monitor Lizards (Squamata: Varanus) endemic to the Louisiade and Tanimbar Archipelagos with A Key to the Subgenus Euprepiosaurus. Journal of Natural History. 57(13-16); 947-975. DOI: 10.1080/00222933.2023.2218574
