The earliest flowers

The fossil record has bequeathed us a wide diversity of pollen and flowers dating from the Cretaceous onwards, but recently published finds from drill cores from Scandinavia and Switzerland have pushed back the evolution of flowering plants a full hundred million years, into the early Triassic (240 million years back) when they may have spread into the newly vacated niches after the end Permian mass extinction, in much the same way that mammals did after the end Cretaceous event.

Pollen is the part of plants that fossilises best, and is extensively used in geology and archaeology to infer both dates in the stratigraphic sequence and help reconstruct the paleo environment. Palynology is a vital part of sedimentary rock studies and excavations of the relics of our human past. The Triassic pollen is similar to that of typical flowering plants, and provides a physical anchor to earlier evidence based on biochemistry that placed their origin anywhere between the Triassic and Cretaceous. The sites where the cores were drilled were subtropical and warm in the Triassic, but Switzerland was much drier than Scandinavia, implying that flowers already had a wide ecological range in that era. The structure of the grains shows that the plants were pollinated by beetles (unless a fossil bee turns up since the oldest so far come from the Cretaceous), and I wonder what sort of scent the flowers may have deployed to attract them...

Loz