The Eocene (symbol Eoâ) epoch, lasting from 56 to 33.9 million years ago, is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the Grande Coupure (the "Great Break" in continuity) or the EoceneâOligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of the epoch are well identified, though their exact dates are slightly uncertain.
Scientists who studied sediment cores drilled from the ocean floor off the Antarctic coast, have found on subsequent analysis fossil pollens that came from a tropical forest. Most likely, the continent was covered by rainforest some 52 million years ago. The researchers involved warn however that by the end of the century, ice from the [...]
After the great dinosaur extinction some 65 million years ago, mammals finally had their big shot as numerous niches became free for the taking. Thus, from mouse size, some mammal species surfaced which were as large as a bus, the so called mammal megafauna, like mammoths, giant sloths or saber-tooth tigers. However, a dire trial of their [...]
A newly published paper in the journal Science provides a worrisome report – the world’s oceans are acidifying at a rate, which if set to continue, will be unprecedented in the last 300 million years. The scientists report that this comes as a direct consequence of the alarming ever increasing carbon dioxide concentration in the atmosphere, [...]
Bergmann’s rule states that mammals of a given genus or species are smaller in hotter climates, and bigger in colder climates. Adapted, when faced with climate change cycles, mammals shirk as temperature rises and scale back up in size, once the cycle ends and makes room for cooling. Simple correlation, based on fossils and temperature readings [...]