Details sparse, but big picture emerges for past 65 million years
Paleobotanical data for Africa are generally meager and uneven for the Cenozoic, according to Jacobs and her co-authors.
In an original series of maps, they chart each Cenozoic Africa paleobotanical locale described in the published research to date. There are a mere 82 sites in all. Most of the sites date to 50 million years ago. Fewer date to 20 million, 30 million, 10 million and perhaps most important 2 million years ago, when the human family was evolving.
"Africa is disappointingly undersampled," say Jacobs and her colleagues. "This vast continent, roughly three times the area of the United States, has so far been documented by only a handful of Paleogene plant and vertebrate localities, and it has a Neogene record heavily biased toward the depositional basins of the East African Rift."
Shift from descriptive to analytic approach driven by holistic view
For a continent so important for its role in the evolution of mammals, the scarcity of plant fossil data stands in sharp contrast.
"As impressive as is the contemporary mammalian diversity of Africa, it is dwarfed by that of the Cenozoic," write the volume's editors, paleozoologist Lars Werdelin, the Swedish Museum of Natural History, and paleontologist William Joseph Sanders, the University of Michigan. Africa today represents 20 percent of the world's land mass, is the only continent to occupy both the north and south temperate zones, and is home now to more than 1,100 mammalian species, they write in the introduction.
Africa's paleobotanical record is key to a holistic understanding of ancient mammals, says H.B.S. Cooke in the preface. A mammal expert, Cooke was editor of the earlier 1978 scientific reference, "Evolution of African Mammals" (Harvard University Press).
"Most striking over the past years has been a shift in studying fossils from a larg
|Contact: Margaret Allen|
Southern Methodist University