A New Species of Alopoglossus Boulenger (1885) (Squamata, Alopoglossidae) from the Lowlands of the Eastern Guiana Shield, with Assessment of the Taxonomic Status of A. copii surinamensis
Two species of Alopoglossus (A. angulatus and A. meloi) were recognized to occur in the Guiana Shield lowlands, northeastern Amazonia. A third group of populations forming a distinct genetic lineage related to Alopoglossus avilapiresae was recently documented in the region. The Guiana Shield lowlands area also encompasses the type locality of Alopoglossus copii surinamensis (currently considered a synonym of A. angulatus). Aiming at describing a possible new species of Alopoglossus from the Guiana Shield and evaluating the taxonomic status of A. copii surinamensis, we analyzed variation in scutellation and morphometrics of the two nominal species of Alopoglossus occurring in the Guiana Shield and A. avilapiresae, which was recovered as the sister clade of the new Guiana Shield lineage, by examining 361 specimens from French Guiana, Brazil, Suriname, Guyana, Colombia, Ecuador, and Peru. Our results revealed a distinct combination of diagnostic characters that supports the description of specimens displaying the third Guiana Shield lineage as a new species. The new species is also distinct from A. copii surinamensis that we retain under a synonym of A. angulatus after examination of all species of the angulatus group and by considering updated diagnostic characters. The new taxon described here increases the total number of known species of Alopoglossus to 15. Duas espécies de Alopoglossus (A. angulatus e A. meloi) são reconhecidas nas planícies do Escudo Guianense, no nordeste da Amazônia. Um terceiro grupo de populações, formando uma linhagem distinta relacionada à A. avilapiresae, foi recentemente documentada na região. Esta área também abriga a localidade-tipo de A. copii surinamensis (atualmente considerada sinônimo de A. angulatus). Com o intuito de descrever esta possível terceira espécie de Alopoglossus do Escudo das Guianas, e avaliar o status taxonômico de A. copii surinamensis, nós analisamos a variação na escutelação e morfometria de duas formas nominais de Alopoglossus que ocorrem no Escudo das Guianas e A. avilapiresae, a qual foi reconhecida como grupo irmão da linhagem nova do Escudo das Guianas, através da análise de 361 espécimes da Guiana Francesa, Brasil, Suriname, Guyana, Colômbia, Ecuador e Peru. Nossos resultados revelaram uma combinação distinta de caracteres que sustentam a descrição dos espécimes da terceira linhagem do Escudo das Guianas como pertencentes a uma nova espécie. A nova espécie é também distinta de A. copii surinamensis, o qual mantemos como sinônimo de A. angulatus após análise de todas as espécies do grupo angulatus e considerando caracteres diagnósticos atualizados. O novo taxon aqui descrito aumenta o número total de espécies descritas de Alopoglossus para 15. Deux espèces d'Alopoglossus (A. angulatus et A. meloi) ont été jusqu'à présent identifiées dans les zones de basse altitude du bouclier guyanais, une région correspondant au nord-est de l'Amazonie. Un troisième groupe de populations, formant une lignée génétique distincte apparentée à A. avilapiresae, a récemment été documenté dans cette région. Cette zone englobe également la localité type d'A. copii surinamensis (actuellement considéré comme synonyme d'A. angulatus). Dans le but de décrire cette possible nouvelle espèce d'Alopoglossus du bouclier guyanais et d'évaluer le statut taxonomique d'A. copii surinamensis, nous avons analysé l'écaillure et la variation morphométrique des deux espèces nominales d'Alopoglossus présentes dans le bouclier guyanais ainsi que d'A. avilapiresae, l'espèce sœur de la nouvelle lignée du bouclier guyanais. Nous avons ainsi examiné 361 spécimens de Guyane Française, Brésil, Suriname, Guyana, Colombie, Équateur et Pérou. Nos résultats ont révélé une combinaison de caractères diagnostiques qui soutient la description des spécimens présentant la troisième lignée du bouclier guyanais comme étant une nouvelle espèce. Cette nouvelle espèce est également distincte d'A. copii surinamensis que nous retenons comme un synonyme d'A. angulatus après examen de toutes les espèces du groupe angulatus et compte tenu des caractères diagnostiques actualisés. Le nombre total d'espèces connues d'Alopoglossus atteint 15 avec le nouveau taxon décrit ici.ABSTRACT
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Principal component analysis (PCA) of (A) meristic characters and (B) measurements between specimens of A. angulatus (black dots), A. avilapiresae (yellow squares), A. meloi (green diamonds), and “Alopoglossus sp.” (red stars).
(A) Dorsal and (B) ventral views of the holotype of Alopoglossus theodorusi sp. nov. (MNHN-RA-2020.0019). Scale bar = 1 cm.
(A) Dorsal, (B) ventral, and (C) lateral views of the head and neck of the holotype of Alopoglossus theodorusi sp. nov. (MNHN-RA-2020.0019). Scale bar = 1 cm.
Ventral views of the head of the (A) paratype of Alopoglossus theodorusi sp. nov. (MNHN-RA-2020.0020), (B) holotype of Alopoglossus amazonius (UMMZ 56853), and (C) holotype of Alopoglossus meloi (MPEG 24372).
Dorsal views of the head of the (A) holotype of Alopoglossus theodorusi sp. nov. (MNHN-RA-2020.0019), (B) paratype of Alopoglossus theodorusi sp. nov. (MNHN-RA-1996.4472), and (C) neotype of Alopoglossus angulatus (RMNH 15200); ventral views of the head of the (D) holotype of Alopoglossus theodorusi sp. nov. (MNHN-RA-2020.0019), and (E) neotype of Alopoglossus angulatus (RMNH 15200).
Lateral views of the head of (A) Alopoglossus theodorusi sp. nov. from Lourenço, Amapá, Brazil (photo: Sergio Souza), and (B) Alopoglossus angulatus (MNHN-RA-2020.0028).
Dorsal views of the head of the (A) holotype of Alopoglossus theodorusi sp. nov. (MNHN-RA-2020.0019), (B) paratype of Alopoglossus theodorusi sp. nov. (MNHN-RA-1996.4472), and (C) holotype of Alopoglossus avilapiresae (INPA-H 9515).
Ventral views of the head of the (A) holotype of Alopoglossus theodorusi sp. nov. (MNHN-RA-2020.0019), (B) holotype of Alopoglossus andeanus (MCZ 45590), and (C) holotype of Alopoglossus carinicaudatus (ANSP 11371).
Lateral views of the head of the (A) holotype of Alopoglossus theodorusi sp. nov. (MNHN-RA-2020.0019), (B) Alopoglossus theodorusi sp. nov. from Lourenço, Amapá, Brazil (photo: Sergio Souza), and (C) holotype of Alopoglossus collii (CHUNB 18038).
Living specimen of Alopoglossus theodorusi sp. nov.: (A) holotype MNHN-RA-2020.0019, photo: Antoine Fouquet; (B) specimen from Lourenço, Amapá, Brazil, photo: Sergio Souza; (C) dorsal and (D) ventral views of specimen from Mont Belvedere, French Guiana, not collected, photos: Michel Blanc.
(A) Distributional records of eastern Amazonian species of Alopoglossus (black dots: A. angulatus; green diamonds: A. meloi; red stars: A. theodorusi; white symbols: type-localities); (B) distributional records of A. theodorusi in French Guiana and Amapa State, Brazil; (C) living specimens of Alopoglossus angulatus (above) and A. theodorusi (below), both from Mont Galbao, French Guiana, photos: Mael Dewynter & Elodie Courtois. *Note differences on temporal scales (Alopoglossus angulatus, strongly keeled aspect; A. theodorusi, smooth general aspect).
(A) Dorsal and (B) ventral views of the holotype of Alopoglossus copii surinamensis (RMNH.RENA.4858). Scale bar = 1 cm.
(A) Dorsal, (B) ventral, and (C) lateral views of the head and neck of the holotype of Alopoglossus copii surinamensis (RMNH.RENA.4858). Scale bar = 1 cm.
Principal component analysis (PCA) of meristic characters considering only males (A) and only females (B) between specimens of A. angulatus (black dots), A. avilapiresae (yellow squares), A. meloi (green diamonds), and “Alopoglossus sp.” (red stars).
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