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| (A–D) Lygodactylus leopardinus sp. nov. in life and habitat from type locality at Équateur Province, DRC. (F–I) L. gamblei sp. nov. in life and photo of habitat from type locality at Tanganyika Province, DRC. Lobón-Rovira, Bauer, Pinto, Trape, Conradie, Kusamba, Júlio, Cael, Stanley, Hughes, Behangana, Masudi, Pauwels & Greenbaum, 2023 |
Abstract
Lygodactylus is the most speciose gekkonid group in Africa, with several additional, candidate species already identified from previous studies. However, in mainland Africa, several groups remain only partially resolved, and there are several taxonomic inconsistencies. Lygodactylus gutturalis was described from Guinea-Bissau in the 1870s and since then, the species has been recorded from West to East Africa, and it is widely distributed through different biomes and ecoregions. However, this taxon has never been studied in detail. In this work, we use an integrative approach, including molecular phylogenetic analysis, morphometrics, skull osteology, and biogeography to provide the first systematic revision of the L. gutturalis species complex. The L. gutturalis complex is a subgroup within the L. picturatus group and includes nine well-differentiated species. We elevate Lygodactylus gutturalis dysmicus to full species status, recognize Lygodactylus depressus as the sister species to L. gutturalis, describe five new species (Lygodactylus kibera sp. nov., Lygodactylus karamoja sp. nov., Lygodactylus mirabundus sp. nov., Lygodactylus leopardinus sp. nov., and Lygodactylus gamblei sp. nov.), and propose an additional candidate species that requires further research. Also, in order to shed light on some taxonomic inconsistencies between the L. gutturalis and Lygodactylus angularis groups, we revisit the L. angularis group, within which we elevate Lygodactylus angularis heeneni and Lygodactylus angularis paurospilus to full species status. The L. gutturalis subgroup diversified during the Late Miocene (between 5–15 Mya), probably as a consequence of multiple vicariant events driven by the expansion of the African savannahs and the establishment of climatic refugia.
Keywords: Africa, biogeography, climatic refugia, CT-scan, Gekkonidae, Miocene, phylogeny, systematics
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| Geographical distribution of the Lygodactylus gutturalis complex in Africa, on a hybrid map of the major vegetation divisions (Sayre et al. 2013) and 1 arc-second elevation map across tropical Africa (NASA 2000). Different colours depict records of different species within the L. gutturalis subgroup; see inset for explanations of symbols. White circles denote records of L. cf. gutturalis that cannot be assigned to any of the nominate taxa. Black stars represent the type localities of each nominate taxon within the L. picturatus subgroup (1– L. picturatus, 1S– L. picturatus sudanensis, 1U– L. picturatus ukerewensis, 2– L. inexpectatus, 3– L. keniensis, 4– L. kimhowelli, 5– L. manni, 6– L. mombasicus, 7– L. scorteccii, 8– L. tsavoensis, 9– L. wojnowskii, 10– L. williamsi). |
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| Specimens of L. gutturalis in life from (A–C) Guinea Bissau Photographs by J.F.T. (A–C and F). |
LYGODACTYLUS GUTTURALIS S.S. (Bocage, 1873)
LYGODACTYLUS DYSMICUS Perret, 1963
LYGODACTYLUS DEPRESSUS Schmidt, 1919
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| Specimens of Lygodactylus kibera sp. nov. in life or freshly euthanized from (A) Mpishi (holotype: UTEP 22566), near Kibira National Park, Bubanza Province, Burundi, (B) N'Komo River (UTEP 22586), South Kivu Province, DRC, and (C) Bujumbura city, Bujumbura Mairie Province (UTEP 22576), Burundi. Photo of habitat at (D) Mpishi, Bubanza Province, Burundi. Photographs by E.G. (A–C) and C.K. (D). |
LYGODACTYLUS KIBERA SP. NOV.
Etymology: The name ‘kibera’ derives from the word ‘kibira’ or ‘kibera’ in Kinubi—a Sudanese Arabic-based creole language spoken in some regions of Burundi, Kenya, and Uganda—that means ‘forest’, the main habitat type associated with the species.
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| Specimens of Lygodactylus karamoja sp. nov. in life from (A–B) Agoro Town (holotype: UTEP 22590), Imatong Foothills and (D–E) Nakapiripirit (UTEP 22594), Mount Kadam, Northern Region, Uganda. Photo of habitat at (C) Imatong Foothills, and (F) Mount Kadam, Northern Region, Uganda. Photographs by D.F.H. |
LYGODACTYLUS KARAMOJA SP. NOV.
Etymology: The name ‘karamoja’ is a noun in apposition and refers to the Karamoja region in north-eastern Uganda where many individuals of this species have been found. The species is named in honour of this arid region, which is occupied by the Karamojong people who are mostly nomadic pastoralists related to the Maasai in Kenya.
LYGODACTYLUS MIRABUNDUS SP. NOV.
Etymology: The name ‘mirabundus’ is a Latin adjective that means ‘astonishing or surprising’. The species is only known from a unique location in a transition zone between dry savannah and the Congolian Rainforest.
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| A–B, Holotype (UTEP 22577) and (C–D) paratype (UTEP 22596) of Lygodactylus leopardinus sp. nov. in life and photo of habitat from (E) type locality at Balolombo Village, Busira River, Équateur Province, DRC. F–G, Holotype (UTEP 22587) and (H–I) paratype (UTEP 22584) of L. gamblei sp. nov. in life and photo of habitat from (J) type locality at Manono, Tanganyika Province, DRC. Photographs by E.G. |
LYGODACTYLUS LEOPARDINUS SP. NOV.
Etymology: The name ‘leopardinus’ is an adjective referring to the leopard-like dorsal pattern present in males of this species.
LYGODACTYLUS GAMBLEI SP. NOV.
Etymology: We name this new species after the American evolutionary biologist and herpetologist Tony Gamble of Marquette University, in recognition of his substantial contributions to the evolutionary biology of geckos. The name is a patronym formed in the genitive case.
Conclusion:
We provide a complete integrative approach for the L. gutturalis subgroup, which revealed cryptic diversity that we rectified with the description of five new taxa, the revalidation of another, and the tentative proposal of one additional candidate species, all previously considered to be conspecific. We also revisited the L. angularis group to revalidate two additional taxa. As a consequence of this work, we elevate the number of recognized Lygodactylus species from 82 to 90. Moreover, the morphological variation found within L. angularis suggests a more extensive cryptic diversification within this group that requires further investigation. Additional work in some regions of Africa, including Ethiopia, Somalia, Kenya, and Tanzania may lead to the description of additional species. Diversification events during the Late Miocene (between 5–15 Mya) are likely linked to the expansion of African savannahs and the establishment of climatic forest refugia. This suggests that the L. gutturalis group is the result of a non-adaptative radiation, a consequence of multiple vicariance events during the Miocene that fragmented and prevented genetic connectivity between morphologically and ecologically similar taxa.
Javier Lobón-Rovira, Aaron M Bauer, Pedro Vaz Pinto, Jean-Francois Trape, Werner Conradie, Chifundera Kusamba, Timóteo Júlio, Garin Cael, Edward L Stanley, Daniel F Hughes, Mathias Behangana, Franck M Masudi, Olivier S G Pauwels and Eli Greenbaum. 2023. Integrative Revision of the Lygodactylus gutturalis (Bocage, 1873) Complex unveils extensive Cryptic Diversity and Traces its Evolutionary History. Zoological Journal of the Linnean Society. zlad123. DOI: 10.1093/zoolinnean/zlad123
