Older than you think

Scientists believe that both oxygen and plants may be millions of years older than we originally thought. Oxygen is now thought to have appeared in the Earth's atmosphere 3 billion years ago - that's over 600 million years older than previously calculated! Originally, oxygen was thought to have accumulated 2.3 billion years ago during the Great Oxygenation Event, but 3 billion year old rocks and soils show evidence for low amounts (less than 1% of the Earth's atmosphere) of oxygen much earlier. Oxygen levels have fluctuated greatly over time, reaching a maximum of 35% towards the end of the Carboniferous (300 million years ago). We now have around 20% oxygen in our atmosphere, due to photosynthetic bacteria, trees and plants that take in carbon dioxide and give out the oxygen that we need to breath. For more information about this story, see the link below.
http://www.sci-news.com/geology/science-oxygen-atmosphere-01413.html
The other story in the news recently is how flowering plants may be 100 million years older than we previously thought, pushing them back from the Early Cretaceous period (100-145 million years ago), to the Middle Triassic (235-247 million years ago). This is thanks to research carried out on six fossil pollen grains that have been found in Middle Triassic core samples. These grains are very similar to ones that have been previously found, but as they are so rare, they cannot tell us much about the climate. There is also a gap in the record from this time to the Early Cretaceous (that's 100 million years!) where no pollen grains have been found. This could either mean that flowering plants died out during that period, that the grains just haven't been found yet, or that the dating of the new grains has been incorrect. For more information, see the link below.
http://www.bbc.co.uk/nature/24331982