FROM THE EDUCATION DESK
Last month I wrote that I could smell Fall in the air…this did not last long enough for me! It has been so cold these last few days and we got our first snow of the season. As much as I hate to see our colorful leaves disappear, we did need some form of moisture to help with all the fires and I am grateful for this happening.
FYI: Why did birds survive?
About 150 million years ago, in the Jurassic Period, the first birds evolved from small, feathery, raptor- like dinosaurs, becoming another branch on the dinosaur family tree. With hindsight, birds can be categorized as avian dinosaurs. About 66 million years ago an asteroid more than 6 miles across struck what is now the Yucatan peninsula, triggering the fifth mass extinction in the world’s history. More than 75 percent of species known from the end of the Cretaceous period did not make it to the following Paleogene period. The geologic break between the two is called the K-Pg boundary, and beaked birds were the only dinosaurs to survive the disaster. The end of the Cretaceous had an entire array of birds and bird-like reptiles, but It was only the beaked birds that survived. All living birds have toothless beaks, but it was not always so.
A great spotted woodpecker eats a hazelnut. Bird beaks may have allowed the animals to eat seeds and nuts after an asteroid hit the earth, wiping out many forms of life. (Photo by: Arterra/Universal Images Group via Getty Images)The 150 million year old Archaeopteryx, the first bird, had teeth. Paleontologists have noticed that some dinosaur groups, including birds, evolved beaks and lost teeth as they became more herbivorous. The earliest birds had teeth to get insects and some began to specialize on fruit, seeds and other plant food. The birds evolved beaks to pluck and pick instead of beaks to catch.
When the extinction struck, the traits birds had been evolving for millions of years made the difference between life and death. Not all birds survived this impact and its aftermath. Entire groups of birds, such as toothed birds called enantiornithes, went extinct. Beaked birds were able to feed on the seeds of the destroyed forests and wait out the decades until vegetation began to return. Just having a beak was not enough. The birds with beaks and powerful gizzards capable of crushing tough seeds had an unexpected advantage that increased their chances of survival. Many bird lines became smaller in size while maintaining their brain size.
Herbivorous mammals and non-avian dinosaurs evolved ever-growing teeth so they could continue eating as the plants wore their teeth down. This was not possible with a beak.
To understand more about how birds managed to survive this extinction we need to find more fossils from the time directly following this mass extinction, the Paleocene. Paleontologists have examples of fossil birds from about 10 million years after the disaster during the Eocene. Bird fossils from between the Cretaceous and the Eocene are fragmentary and hard to find. These bones as they are found may reveal new secrets.
Credit to: Riley Black…Smithsonianmag.com