Browsing by Author "Luedecke, Tina"

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    Carbon, nitrogen, and oxygen stable isotopes in modern tooth enamel: A case study from Gorongosa National Park, central Mozambique
    (2022) Luedecke, Tina; Leichliter, Jennifer N.; Aldeias, Vera; Bamford, Marion K.; Biro, Dora; Braun, David R.; Capelli, Cristian; Cybulski, Jonathan D.; Duprey, Nicolas N.; da Silva, Maria J. Ferreira; Foreman, Alan D.; Habermann, Joerg M.; Haug, Gerald H.; Martinez, Felipe, I; Mathe, Jacinto; Mulch, Andreas; Sigman, Daniel M.; Vonhof, Hubert; Bobe, Rene; Carvalho, Susana; Martinez-Garcia, Alfredo
    The analyses of the stable isotope ratios of carbon (delta C-13), nitrogen (delta N-15), and oxygen (delta O-18) in animal tissues are powerful tools for reconstructing the feeding behavior of individual animals and characterizing trophic interactions in food webs. Of these biomaterials, tooth enamel is the hardest, most mineralized vertebrate tissue and therefore least likely to be affected by chemical alteration (i.e., its isotopic composition can be preserved over millions of years), making it an important and widely available archive for biologists and paleontologists. Here, we present the first combined measurements of delta C-13, delta N-15, and delta O-18 in enamel from the teeth of modern fauna (herbivores, carnivores, and omnivores) from the well-studied ecosystem of Gorongosa National Park (GNP) in central Mozambique. We use two novel methods to produce high-precision stable isotope enamel data: (i) the "oxidation-denitrification method," which permits the measurement of mineral-bound organic nitrogen in tooth enamel (delta N-15(enamel)), which until now, has not been possible due to enamel's low organic content, and (ii) the "cold trap method," which greatly reduces the sample size required for traditional measurements of inorganic delta C-13(enamel) and delta O-18(enamel) (from >= 0.5 to <= 0.1 mg), permitting analysis of small or valuable teeth and high-resolution serial sampling of enamel. The stable isotope results for GNP fauna reveal important ecological information about the trophic level, dietary niche, and resource consumption. delta N-15(enamel) values clearly differentiate trophic level (i.e., carnivore delta N-15(enamel) values are 4.0 parts per thousand higher, on average, than herbivores), delta C-13(enamel) values distinguish C-3 and/or C-4 biomass consumption, and delta O-18(enamel) values reflect local meteoric water (delta O-18(water)) in the park. Analysis of combined carbon, nitrogen, and oxygen stable isotope data permits geochemical separation of grazers, browsers, omnivores, and carnivores according to their isotopic niche, while mixed-feeding herbivores cannot be clearly distinguished from other dietary groups. These results confirm that combined C, N, and O isotope analyses of a single aliquot of tooth enamel can be used to reconstruct diet and trophic niches. Given its resistance to chemical alteration, the analysis of these three isotopes in tooth enamel has a high potential to open new avenues of research in (paleo)ecology and paleontology.
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    The first Miocene fossils from coastal woodlands in the southern East African Rift
    (2023) Bobe, Rene; Aldeias, Vera; Alemseged, Zeresenay; Anemone, Robert L.; Archer, Will; Aumaitre, Georges; Bamford, Marion K.; Biro, Dora; Bourles, Didier L.; Boyd, Melissa Doyle; Braun, David R.; Capelli, Cristian; Coelho, Joao d'Oliveira; Habermann, Joerg M.; Head, Jason J.; Keddadouche, Karim; Kupczik, Kornelius; Lebatard, Anne-Elisabeth; Luedecke, Tina; Macoa, Amelia; Martinez, Felipe I.; Mathe, Jacinto; Mendes, Clara; Paulo, Luis Meira; Pinto, Maria; Presnyakova, Darya; Pueschel, Thomas A.; Regala, Frederico Tata; Sier, Mark; da Silva, Maria Joana Ferreira; Stalmans, Marc; Carvalho, Susana
    The Miocene was a key time in the evolution of African ecosystems witnessing the origin of the African apes and the isolation of eastern coastal forests through an expanding arid corridor. Until recently, however, Miocene sites from the southeastern regions of the continent were unknown. Here, we report the first Miocene fossil teeth from the shoulders of the Urema Rift in Gorongosa National Park, Mozambique. We provide the first 1) radiometric ages of the Mazamba Formation, 2) reconstructions of paleovegetation in the region based on pedogenic carbonates and fossil wood, and 3) descriptions of fossil teeth. Gorongosa is unique in the East African Rift in combining marine invertebrates, marine vertebrates, reptiles, terrestrial mammals, and fossil woods in coastal paleoenvironments. The Gorongosa fossil sites offer the first evidence of woodlands and forests on the coastal margins of southeastern Africa during the Miocene, and an exceptional assemblage of fossils including new species.