The Paleontological Prescience of Monty Python
An interesting fossil find last spring opened a new door in our knowledge of avian evolution: a bird fossil from the Isle of Mors, in Denmark, is thought to represent the earliest parrot specimen yet discovered. Score one for the prescience of Monty Python . . .
Why is this exciting? First of all, it is extremely difficult to find bird fossils in the first place. They have pneumatized bones in order to aid their respiration (many people assert that the main reason for the air cavities in their skeletons is to decrease weight so they can fly, but bats fly just fine with solid bones and many non-flying dinosaurs had pneumatized skeletons as well), and these delicate remains rarely survive long enough to be fossilized.
Second, what is the significance of this creature popping up in Norway? Finding a basal member (or remnants thereof) of any group of animals gives us extremely valuable insight into the geographic origins of the clade. Therefore, since the oldest known bird identifiable as a parrot has been found in Scandanavia, it is a hint that the birds could have original evolved in the Northern Hemisphere and later migrated southwards.
Today, parrots (order Psittaciformes) are found mainly in the Southern hemisphere, not straying far north from the tropics. The only species native to North America, the Carolina Parakeet (Conuropsis carolinesis) was driven extinct in the early 20th century. Since modern parrots are unable to survive winters in the Northern Hemisphere, how could they have gotten a start in chilly Denmark? See for yourself what happens to parrots during winter…
Ok, back to science. The answer to how they survived Scandanavia, of course, is climate change. The new fossil dates back 54 million years, to the Eocene epoch. During this time, Europe had a pleasantly warm climate, with much of the current landmasses covered in lagoons. Under these conditions, the parrots we known and love could develop, and as the climate slowly cooled, they had time to shift to more southern habitats.
This is yet another example of why the current climate changes are a crisis. If the Eocene had cooled as fast as our climate is now warming, would we have macaws and cockatoos today? Just something to think about.
(Republished from my previous blog, Pondering Pikaia, 5/24/08)