Phylogeny and phylogeography of chelonians from sub-Saharan Africa—A review of current knowledge in tribute to Margaretha D. Hofmeyr

Abstract

Species-level phylogeny and especially phylogeography of African chelonians is a comparatively under-studied field of research. We review the current knowledge of phylogeny and phylogeography, highlight congruence of spatial phylogeographic patterns amongst chelonians and other taxa and suggest future research directions to address gaps in knowledge. Our review shows that phylogeographic and phylogenetic investigations have led to unexpected findings. For example, for Pelomedusa, a putatively wide-ranging monotypic terrapin genus, cryptic diversity was revealed, with more than ten species being uncovered. The formerly recognized tortoise genus Homopus sensu lato was found to be paraphyletic with respect to Chersina. To resolve this situation, Homopus was restricted to the four-toed species H. areolatus and H. femoralis and the genus Chersobius was resurrected for the five-toed species C. boulengeri, C. signatus, and C. solus. Three previously recognized taxa were shown to be invalid, viz. the putatively extinct terrapin species Pelusios seychellensis and the tortoise subspecies Chersobius signatus cafer and Stigmochelys pardalis babcocki. Together with taxonomy, the knowledge of phylogeographic structuring sets a solid foundation for conservation measures and allows the identification of Management and Conservation Units. However, the current legislation, in particular the enforcement of the Nagoya Protocol under the Convention of Biological Diversity (CBD), has largely halted research on widely distributed taxa and turned the well-intended concept of Access and Benefit Sharing into a major impediment for conservation and research. The current situation leads for many species to a continued usage of outdated and incorrect taxonomic classifications resulting in an error cascade of conservation decisions. This is counterproductive to the aims of the CBD, that is, the protection of biodiversity. Sequencing historical DNA from museum specimens using aDNA approaches could be a short-term approach to mitigate, but not solve, this impediment.

An island in a sea of sand: a first checklist of the herpetofauna of the Serra da Neve inselberg, southwestern Angola

“…A wide-ranging species from eastern Africa to southwestern and central Angola. Historically, the taxonomic status of Kinixys populations in Angola has been uncertain (for further discussion see Marques et al 2018 ), although according to the most recent sub-Saharan Africa chelonian phylogeny ( Fritz et al 2022 ), the Angolan material should be assigned to Kinixys belliana . This species is frequently consumed a delicacy by the Mucubal tribe at the base of Serra da Neve (pers.…”

Honoring the Legacy of Professor Margaretha Delina Hofmeyr (1950–2020)

“…Retha's keen intellect and robust foundation in physiological ecology and integrative biology (e.g., Gericke et al 1978; Hofmeyr 1985; Schumann et al 2005) helped her tackle the challenge of southern Africa's rich tortoise diversity, with 14 native taxa, many endemic, and several endangered species (Fritz et al 2022). Fostered by collaborations with esteemed colleagues Ernst Baard, Gerald Kuchling, and Uwe Fritz, Retha authored or coauthored more than 60 peer-reviewed chelonian articles with topics ranging from morphometrics and physiology to reproductive ecology, behavior, forensics, phylogeography, phylogenetics, genetics, evolution, and conservation (e.g., Hofmeyr 2004, 2009; Hofmeyr et al 2005; Leuteritz and Hofmeyr 2007; Loehr et al 2007; Fritz et al 2011; Henen et al 2013; Rhodin et al 2018; Kuchling and Hofmeyr 2022).…”