Patterns in the diversity and endemism of extant Eocene age lineages across southern Africa

Abstract

Southern Africa boasts a wealth of endemic fauna and flora, comprising both massive recent radiations such as those characteristic of the Cape flora, and solitary ancient species such as the peculiar desert gymnosperm Welwitschia. This study was undertaken to identify ancient biological lineages (tetrapod and vascular plant lineages of Eocene age or older) endemic to southern Africa, and to map their distribution across the region. Twenty-seven (17 plant and ten animal) lineages were identified, and distribution maps were generated for each of them across 74 operational geographic units, which were then combined into total endemism and corrected weighted endemism per unit area. Total endemism peaked along South Africa's coast and Great Escarpment, but in the case of weighted endemism high values were also recorded along other portions of the Great Escarpment further north. A review of the lineages sister to southern African ancient endemic lineages showed that these are often globally widespread, and many of them differ substantially from the southern African ancient lineages in terms of morphology and ecology. The mechanisms of ancient lineage survival in the region are discussed, and their importance for conservation in southern Africa is emphasised.

Two New Species ofPterydriasReitter (Coleoptera: Ripiphoridae), Significantly Expanding the Biogeographic Range of the Genus

“…Nonetheless, the observed distributions, particularly those between Europe and sub-Saharan Africa and southern Asia, are commonly found among many groups (Grimaldi and Engel 2005), especially when looking at lineages surviving in the latter regions and known from Tertiary fossils in the former (e.g., Ander 1942;Böhme and Weitschat 1998;Engel 2001;Engel et al 2007Engel et al , 2013aPadayachee and Procheş 2016), or even strictly fossil lineages that link the past fauna of Europe with southern Asia (e.g., Grimaldi and Singh 2012;Engel et al 2013b). It is likely that several ripidiine genera or more inclusive clades were widespread during parts of the Tertiary and have subsequently become more restricted in distribution.…”

“…The specific epithet is based on Pondoland, a coastal belt below the Great Escarpment and along the Indian Ocean in the Eastern Cape Province of South Africa and the former lands of the indigenous Pondo Kingdom (annexed by the colony in 1894). The region is known for, among other things, its considerable biotic diversity (a portion of the Maputaland-Pondoland-Albany biodiversity hotspot: Forest et al 2007;Padayachee and Procheş 2016). We name this species after the region to highlight its importance and biological distinctiveness, and the need for its conservation.…”

Does biogeography need species?

“…The idea of mapping them may be rooted in basal versus derived lineage comparisons (Hawkins et al, 2006), and true equal-age lineages were first mapped by Davies and Buckley (2012; 'local lineages through time'). Such maps can illustrate lineage survival from specific age intervals, and provide a picture of refugial value (Procheş et al, 2015;Padayachee and Procheş, 2016) that cannot be encapsulated by phylogenetic diversity, where recent diversifications can add up to match the values derived from ancient lineages (Forest et al, 2007).…”

Climate refugia for three Afromontane forest‐dependent bird species in south‐eastern South Africa

“…Comparatively stable equatorial conditions have fostered higher forest biodiversity in the EA Hotspot than in the MPA Hotspot (Pinkert et al, 2020), although forests in the latter region retain considerable endemism across multiple taxa (Padayachee & Procheş, 2016; Perera et al, 2018). The MPA Hotspot lies at the confluence between tropical trade winds and southern westerlies, and likely experienced high rainfall conducive to forest presence during the late Pleistocene (Simon et al, 2015).…”