Palaeocene

This troubling period of time for Earth's plant life is known as the "Palaeocene megaherbivore gap" — a term that refers to the evolutionary niche that suddenly disappeared, that of large herbivores who feasted on grasses and leaves, all of whom perished in the mass extinction event.

Thus, researchers started by studying both fossilized palms and their living counterparts today, observing how these plants evolved as a result of the Palaeocene megaherbivore gap.

Enormous penguins are believed to have rapidly evolved in the Palaeocene epoch, between 66 and 56 million years ago – after the dinosaurs disappeared and large marine reptiles also vanished from southern hemisphere waters that were much warmer than today.

Dr Vanesa De Pietri, a natural history curator at Canterbury Museum, said the discovery of a second giant penguin from the Palaeocene is further evidence of the large size of ancient penguins.

At about 600 metres, the core will pass through rock from the Palaeocene–Eocene Thermal Maximum, when temperatures spiked about 55 million years ago, creating a greenhouse world.