A new paper appearing this week in the Journal of Vertebrate Paleontology helps to fill in a gap in the fossil record for hippos. Fossils from Chorora, Ethiopia, provide new information about the rapid diversification and increase in abundance of hippos that occurred around 8 million years ago. Here is a report on the work in Nature.
A new paper just published in Proceedings of the National Academy of Sciences promises to shed some light on the relationships of early amphibians. It looks like caecilians, which still exist today, were around way back in the Triassic, and that they may have been closely related to stereospondylids. Here is an accessible summary of the research.
New research published in PNAS looks at the rate at which genetic differences accumulate in populations of birds. Here is a summary of the work. And here's the original paper. The researchers assessed the rate of genetic differentiation in 173 species of birds, and then showed that higher rates of genetic differentiation correlate with higher speciation rates over longer timescales.
Human remains found in Morocco at a site called Jebel Irhoud suggest that our species might be much older than anyone thought--possibly 300,000 years old. Here is a summary of the work. Here is the paper in Nature. And here is a second paper that covers the techniques used to date the remains. The researchers used thermoluminescence dating on lithics that were associated with the human skeletal remains.
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A new paper in the Journal of Human Evolution presents evidence against the hypothesis that the "Hobbits" of the island of Flores are descended from H. erectus. Instead, the authors argue that we have to go deeper into the family tree to find the common ancestor that we humans share with H. floresiensis. Here's an accessible summary of the findings.
A recent paper in PNAS uses ancient DNA research to determine when bison first "invaded" North and South America. The iconic symbols of the N. American west haven't actually been here that long. It turns out that the first migration of bison from Asia occurred between 195 and 135 thousand years ago. Here is a shorter report on the research from The New York Times.
Understanding the causes of the end-Pleistocene megafaunal extinctions in the western hemisphere is really complicated. Recently we shared news of research that appeared to count against the Younger Dryas impact hypothesis. But a new paper offers fresh evidence in favor of that hypothesis: Traces of platinum found at archaeological sites of the right age.
Scientists keep pushing back the age of the earliest known fossils, which also suggests earlier and earlier dates for the first appearance of life on Earth. A new paper in Nature reports on microfossils from Canada alleged to be almost 3.8 billion years old. (Here is an accessible discussion in The Washington Post.)
Getting from a little theropod-thing to a fully-powered flying bird-thing is often presented as a pretty direct trajectory, as "as a long evolutionary march in which natural selection progressively refined one subgroup of dinosaurs into ever-better aerialists". In a new paper in science, Stephen Brusatte argues that recent fossil finds suggest that things were way crazier than that...