Paleontological exploration in Africa: a view from the Rukwa Rift Basin of Tanzania

• Main Authors: Stevens, Nancy J., Gottfried, Michael D., Roberts, Eric M., Kapilima, Saidi, Ngasala, Sifa, O'Connor, Patrick M.
• Other Authors: Fleagle, John G., Gilbert, Christopher C.
• Format: Book Part
• Language: unknown
• Published: Springer 2008
• Subjects: Archibald; Antarc*; Antarctica
• Online Access: https://researchonline.jcu.edu.au/18472/4/18472_Stevens_et_al_2008_Cover.JPG; https://researchonline.jcu.edu.au/18472/5/18472_Stevens_et_al_2008.pdf

[Extract] The Mesozoic-Cenozoic transition was a period of dramatic global change during which time the Earth's continents were in the process of fragmenting from a large, relatively continuous landmass to assume a configuration similar to that seen today. The most significant tectonic activity in the southern hemisphere occurred during the Cretaceous-Paleogene interval, when the large Gondwanan sub-regions of Africa, South America, Australia, Indo- Madagascar and Antarctica became increasingly isolated from one another (Smith et al., 1994; Scotese, 2001). Continental dynamics of this scale are not only geologically significant, they also profoundly influenced the evolution of both terrestrial and marine biotas (Forster, 1999; Krause et al., 1999; Sereno, 1999; Lieberman, 2000; Upchurch et al., 2002; Humphries and Ebach, 2004). Indeed, the Cretaceous-Paleogene transition marks large-scale faunal turnover of major vertebrate and invertebrate taxa (e.g., extinction of nonavian dinosaurs, radiation of "modern" mammals and birds; Cracraft, 2001; Springer et al., 2003, 2004; Archibald and Fastovsky, 2004; Kielan-Jaworowska et al., 2004; Rose and Archibald, 2004; Clarke et al., 2005). Numerous hypotheses have been proposed to explain the origin, diversification, and extinction of many vertebrate groups living on, or dispersing through, Gondwana during the Cretaceous and Paleogene. For example, molecular studies have postulated a Cretaceous-Paleogene African origin for a number of higher-level amniote clades, including Placentalia (Murphy et al., 2001 and references therein), Afrotheria (Hedges et al., 1996; Springer et al., 1997, 2003, 2005; Madsen et al., 2001; van Dijk et al., 2001), and neornthine birds (Cracraft, 2001). In particular, an ancient ( Cretaceous/Paleocene) Gondwanan primate origin has been proposed, with a strepsirrhine-haplorhine divergence occurring shortly thereafter (e.g., Tavare et al., 2002). African origins have also been proposed for a number of Malagasy terrestrial and freshwater groups ...