An amazing discovery of perfectly-preserved amber in Ethiopia has given scientists an unprecedented glimpse of the ecosystem in that region 95 million years ago. These pictures show plants and insects from the Cretaceous woodlands, right after flowering plants had evolved.
Of course "right after" in evolutionary time still involves many hundreds of thousands of years, but the Cretaceous was an era known for the rapid diversification of flowering plants - and with them, new ways that insects and plants could interact to reproduce. Or, as the international team of authors puts it in their paper in PNAS today:
Ancient arthropods belonging to the ants, wasps, thrips, zorapterans, and spiders are the earliest African records of these ecologically important groups and constitute significant discoveries providing insight into the temporal and geographical origins of these lineages. Together with diverse microscopic inclusions, these findings reveal the interactions of plants, fungi and arthropods during an epoch of major change in terrestrial ecosystems, which was caused by the initial radiation of the angiosperms [flowering plants].
One of the most exciting discoveries was the perfectly-preserved body of a female ant - one of the oldest ever found. All that is known currently is that ants co-evolved with flowering plants, and this new finding could help researchers figure out where ants evolved. In addition, the spider fossil is the second-oldest sheet-weaver ever discovered.
Many of the revelations from the amber were microscopic (including spores and bacteria). Now we know that so-called sooty molds haven't changed much over the past 100 million years. "Once adapted to particular microhabitats," the scientists remark, some organisms keep the same basic shape for millions of years. Good to know that some molds never change.
The top two images are just pictures of the amber. Bottom left are plant spores that the scientists found in insect feces. And the two bottom right images are of plant hairs from ferns.
These are wasps.
Here you can see arthropods and spiders. Importantly, image A shows a wingless worker ant - one of the first discoveries of its kind from this era.