FROM THE EDUCATION DESK
Interesting facts for June: Warren G. Harding was the first US president to broadcast a message over the radio on June 14, 1922.
June 5, 1783 the first sustained flight occurred as a hot air balloon was launched in France by brothers Joseph & Jacques Montgolfier. It ascended about 6000 feet.
Donald Duck made his first appearance on June 9, 1934 in the Walt Disney cartoon “The Wise Little Hen” based on the fairy tale of “The Little Red Hen”.
Duck-billed hadrosaurs walked the earth over 90 million years ago and were one of the most successful groups of dinosaurs. A new study, published in PALEOBIOLOGY, shows that special adaptations in teeth, jaws and in their head crests were crucial, and provides new insights into how these innovations evolved.
They walked on their hind legs and were known for their powerful jaws with multiple rows of extremely effective teeth. They had varied display crests on their head that signaled which species each belonged to and were probably used to attract mates. Some could even sound their special call, using nasal passages through these head crests.
Dr. Tom Stubbs, a researcher and lead author of this study, from Bristol’s School of Earth Sciences said: “Our research shows that a unique hadrosaur feeding apparatus evolved fast in a single burst, and once established, showed very little change. In comparison, the elaborate display crests kept diversifying in several bursts of evolution, giving rise to the many weird and wonderful shapes.”
Professor Mike Benton, co-author of the study added, “Variation in anatomy can arise in many ways and by comparing these two things we hope to provide new insights into the evolution of this important dinosaur group. Co-author Dr. Armin Eisler said, “ We identified branches on the hadrosaur evolutionary tree that showed rapid evolution in different parts of the skeleton. When we looked at the jaws and teeth, we only saw fast evolution on a single branch at the base of the group. The bones that form the display crests showed multiple fast rate branches.
Dr. Albert Prieto-Marquez, a world leading expert on hadrosaurs from the Catalan Institute of Paleontology in Barcelona added, “Our results suggest that evolution can be driven in different ways by natural selection and sexual selection”. Hadrosaurs had a feeding apparatus that was successful and so it did not need massive modification to process their food. Sexual selection drove the evolution of more complex crest shapes, and this is reflected by multiple evolutionary bursts.