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- Gorongosa by the sea: First Miocene fossil sites from the Urema Rift, central Mozambique, and their coastal paleoenvironmental and paleoecological contextsPublication . Habermann, Jörg M.; Alberti, Matthias; Aldeias, Vera; Alemseged, Zeresenay; Archer, Will; Bamford, Marion; Biro, Dora; Braun, David R.; Capelli, Cristian; Cunha, Eugenia; da Silva, Maria Ferreira; Luedecke, Tina; Madiquida, Hilario; Martinez, Felipe I.; Mathe, Jacinto; Negash, Enquye; Paulo, Luis M.; Pinto, Maria; Stalmans, Marc; Regala, Frederico Tata; Wynn, Jonathan G.; Bobe, Rene; Carvalho, SusanaThe East African Rift System (EARS) has played a central role in our understanding of human origins and vertebrate evolution in the late Cenozoic of Africa. However, the distribution of fossil sites along the rift is highly biased towards its northern extent, and the types of paleoenvironments are primarily restricted to fluvial and lacustrine settings. Here we report the discovery of the first fossil sites from the Urema Rift at Gorongosa National Park (central Mozambique) at the southern end of the EARS, and reconstruct environmental contexts of the fossils. In situ and surface fossils from the lower member of the Mazamba Formation, estimated to be of Miocene age, comprise mammals, reptiles, fishes, invertebrates, palms, and dicot trees. Fossil and geological evidence indicates a coastal-plain paleoenvironmental mosaic of riverine forest/woodland and estuarine habitats that represent the first coastal biomes identified in the Neogene EARS context. Receiving continental sediment from source terranes west of today's Urema Graben, estuarine sequences accumulated prior to rifting as compound incised-valley fills on a low-gradient coastal plain following transgression. Modern environmental analogues are extremely productive habitats for marine and terrestrial fauna, including primates. Thus, our discoveries raise the possibility that the Miocene coastal landscapes of Gorongosa were ecologically-favorable habitats for primates, providing relatively stable maritime climate and ecosystem conditions, year-round freshwater availability, and food both from terrestrial and marine sources. The emerging fossil record from Gorongosa is beginning to fill an important gap in the paleobiogeography of Africa as no fossil sites of Neogene age have previously been reported from the southernmost part of the EARS. Furthermore, this unique window into past continental-margin ecosystems of central Mozambique may allow us to test key paleobiogeographic hypotheses during critical periods of primate evolution.
- A missing piece of the Papio puzzle: Gorongosa baboon phenostructure and intrageneric relationshipsPublication . Martinez, Felipe I.; Capelli, Cristian; Ferreira da Silva, Maria J.; Aldeias, Vera; Alemseged, Zeresenay; Archer, William; Bamford, Marion; Biro, Dora; Bobe, Rene; Braun, David R.; Habermann, Jörg M.; Luedecke, Tina; Madiquida, Hilario; Mathe, Jacinto; Negash, Enquye; Paulo, Luis M.; Pinto, Maria; Stalmans, Marc; Tata, Frederico; Carvalho, SusanaMost authors recognize six baboon species: hamadryas (Papio hamadryas), Guinea (Papio papio), olive (Papio anubis), yellow (Papio cynocephalus), chacma (Papio ursinus), and Kinda (Papio kindae). However, there is still debate regarding the taxonomic status, phylogenetic relationships, and the amount of gene flow occurring between species. Here, we present ongoing research on baboon morphological diversity in Gorongosa National Park (GNP), located in central Mozambique, south of the Zambezi River, at the southern end of the East African Rift System. The park exhibits outstanding ecological diversity and hosts more than 200 baboon troops. Gorongosa National Park baboons have previously been classified as chacma baboons (P. ursinus). In accordance with this, two mtDNA samples from the park have been placed in the same mtDNA Glade as the northern chacma baboons. However, GNP baboons exhibit morphological features common in yellow baboons (e.g., yellow fur color), suggesting that parapatric gene flow between chacma and yellow baboons might have occurred in the past or could be ongoing. We investigated the phenostructure of the Gorongosa baboons using two approaches: 1) description of external phenotypic features, such as coloration and body size, and 2) 3D geometric morphometric analysis of 43 craniofacial landmarks on 11 specimens from Gorongosa compared to a pan-African sample of 352 baboons. The results show that Gorongosa baboons exhibit a mosaic of features shared with southern P. cynocephalus and P. ursinus griseipes. The GNP baboon phenotype fits within a geographic clinal pattern of replacing allotaxa. We put forward the hypothesis of either past and/or ongoing hybridization between the gray-footed chacma and southern yellow baboons in Gorongosa or an isolation-by-distance scenario in which the GNP baboons are geographically and morphologically intermediate. These two scenarios are not mutually exclusive. We highlight the potential of baboons as a useful model to understand speciation and hybridization in early human evolution. (C) 2019 Elsevier Ltd. All rights reserved.