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| displaying males Acanthocercus margaritae: (A) from Onesi, Omusati Region, Namibia; (B) from near Ondjiva, Cunene Province, Angola. Wagner, Butler, Ceríaco & Bauer, 2021 SALAMANDRA. 57(4) (A) photo by Jukka Jantunen iNaturalist.org/observations/19637354. (B) photo by Pedro Martins iNaturalist.org/observations/19293652. |
Abstract
We describe a new species of the agamid genus Acanthocercus from Namibia and Angola, based on morphological and molecular evidence. The phylogenetic analysis of a fragment of the mitochondrial 16S rRNA gene suggests that the new species is closely related to the other taxa from southern Africa and is distinct from species from eastern and northeastern Africa. The new species is characterized by its high scale counts (mean scale rows around midbody 136, mean dorsal scale rows 103, mean ventral scale rows 101) and displaying males showing a blue coloration of the head, forelimbs, flanks of the anterior part of the body and distal half of the tail; a very distinct pale vertebral stripe between the blue flanks and enlarged yellowish dorsal scales on the posterior part of the body. In Namibia the species is restricted to a small area of grassland with mopane and Maklani palms in northern Ovamboland, but its distribution in Angola spans a diversity of habitats. We also recognize a potential new species from northern Angola and discuss the preliminary distribution of Acanthocercus in Angola.
Key words. Acanthocercus sp. n., Africa, Namibia, Angola.
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| Images of displaying males of Acanthocercus margaritae sp. n. (A) from Onesi, Omusati Region, Namibia (-17.478164 N, 14.650651 E). Photo by Jukka Jantunen iNaturalist.org/observations/19637354. (B) from near Ondjiva, Cunene Province, Angola [-17.674433 N, 15.799167]. Photo by Pedro Martins [7 December 2018] iNaturalist.org/observations/19293652. |
Acanthocercus margaritae sp. n.
Diagnosis. The new species is included in the genus Acanthocercus because of the combination of a heterogeneous body scalation and a tail that is segmented in distinct whorls. Within this genus, the heterogeneous body scalation refers it to the cyanogaster/atricollis group and the high density of enlarged scales in combination with a black patch on the shoulders places it into the A. atricollis complex. Acanthocercus margaritae sp. n. is a medium sized lizard (mean SVL 112 mm [96–129 mm], mean total length 258 mm [217–299 mm]) of its genus and overall is very similar in morphology to A. atricollis and A. cyanocephalus. However, it is distinct from all other species of the complex in its meristic characters. The new species is characterized by its high numbers of scale counts (mean scale rows around midbody 136, mean dorsal scale rows 103, mean ventral scale rows 101). Displaying males are characterized by a blue coloration of the head, forelimbs, flanks of the upper part of the body and second half of the tail; a pale vertebral band, very distinct between the blue flanks and enlarged yellowish dorsal scales on the lower part of the body.
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| Habitat of Acanthocercus margaritae sp. n. in area of Maklani palms (Hyphaene petersiana) near the Calueque-Oshakati canal system south of Oshikango, Namibia. at the Matunto Post, Bicuar National Park, Huila, where paratype MHNCUP_REP 422 was collected. |
Ecology. Acanthocercus margaritae sp. n. is a tree dweller as is typical for most of the taxa of the species complex (Reaney & Whiting 2002, Wagner et al. 2018). In Namibia it occupies areas on the interior plain of northern Ovamboland at elevations around 1100 m corresponding roughly to the Cuvelai River drainage. The area receives about 400 mm of rain per year, falling mostly in late summer (January through April). Vegetation is characterized by grasslands mixed with open mopane (Colophospermum mopane) woodlands with stands of Maklani palms (Hyphaene petersiana) (Fig 9). However, the area is the most densely populated region in Namibia with significant small-scale agriculture, many villages, and some larger urban centers. Acanthocercus is often seen on both native trees and ornamental trees and shrubs in gardens, as well as on the walls of buildings, although it seems to avoid areas of high human activity. In Angola the species occurs in considerably different habitats (see e.g., Fig. 10), from miombo forest areas to open mopane woodlands (Grandvaux-Barbosa 1970) and anthropogenically transformed landscapes such as farms or even within major urban areas such as Lubango.
Etymology. The species epithet ‘‘margaritae’’ is formed as a genitive Latin noun to honor the Greek scientist Dr. Margarita Metallinou (1985 –2015) whose promising career was tragically cut short on the 2nd of July 2015 by a wildlife encounter in Zambia. This new species is a special tribute to her memory from all the authors of this publication to recognize her enthusiasm, passion and dedication to herpetology.
Philipp Wagner, Brett O. Butler, Luis M. P. Ceríaco and Aaron M. Bauer. 2021. A New Species of the Acanthocercus atricollis complex (Squamata: Agamidae). SALAMANDRA. 57(4); 449–463.
Resumo. Descrevemos neste artigo uma nova espécie de Agamídeo do género Acanthocercus da Namíbia e de Angola, com base em evidências morfológicas e moleculares. A análise filogenética de um fragmento do gene mitocondrial 16S rRNA sugere que a nova espécie é relacionada com outros taxa do sul de África e distinta das espécies do leste e nordeste de África. A nova espécie é caracterizada pelo seu maior número de escamas (média de escamas à volta do corpo de 136, média de escamas em fiada dorsal 103, média de escamas em fiada ventral 101) e pelos machos em coloração exibitiva apresentarem um cor azulada na cabeça, braços, flancos da parte anterior do corpo e parte segunda metade distal da causa; uma linha vertebral pálida bem marcada entre os flancos azuis e as escamas dorsais amareladas presentes no parte posterior do corpo. Na Namíbia a espécie encontra-se restrita a uma pequena área de pradaria com Mutiate e palmeiras Malklani no norte da Ovambolãndia, mas a sua distribuição em Angola engloba uma maior diversidade de habitats. Reconhecemos também a existência de uma potencial nova espécie no norte de Angola e discutimos uma potencial e preliminar distribuição do género Acanthocercus em Angola.
Palavras-chave. Acanthocercus sp. n., África, Namíbia, Angola.