Thought to be extinct for 65 million years, the giants of the past have actually survived, not through DNA preserved in ancient amber but rather in a group of animals present in everyday life: birds.
Last Tuesday, working through the difficulties of campus being shut down for a broken water mane and being relocated to the Bora Laskin building, Dr. Phil Currie presented a lecture entitled “Dinosaurs and the Origin of Birds”.
Currie’s lecture walked listeners through the history of the belief that dinosaurs are the ancestors of birds, and also through the evidence that has been uncovered, as well as some of the feathered dinosaur species we know existed.
“We know that the closest relatives of Tyrannosaurus Rex were in fact small guys and they had feathers on their bodies. Given this fact, we have speculated that the young might require downy feathers for insulation,” said Dr. Currie.
The feather impressions that have been found around many skeletal remains of dinosaurs show that there certainly were feathered dinosaurs. But this is the only evidence scientists have of the dino-avian connection.
Currie points out that “the belief that birds are descendent of dinosaurs is not a new one. Ever since the discovery of the first archaeopteryx skeleton in 1860, people have known there was a clear connection between birds and dinosaurs.”
The dinosaur archaeopteryx lived during the late Jurassic period and was a winged-feathered dinosaur that may or may not have been capable of flight. With only ten specimens of archeopteryx surviving, all of the specimens are, as Dr Currie said “exquisitely preserved.” The feather impressions and fossilized feathers are perfect in their details, some specimens even show the small barbules present on the feathers.
Other evidence exists showing the dino-avian connection. This includes the presence of the wishbone in dinosaur fossils. As Currie said, “At one time it was thought that dinosaurs didn’t have a wishbone, but it was really a misinterpretation of a specimen that pointed to this fact. Scientists didn’t want to see the connection between dinosaurs and birds, so they believed the wishbones they found were something else.”
Another connection between dinosaurs and birds that Currie pointed out was the makeup of the bones. There are two similarities that were quite unique. Both dinosaurs and birds have hollow bones with air holes that make the skeleton both lighter and allow the animal to balance better. The other evident skeletal similarity occurs only in females.
Female birds have large deposits of calcium lining the inside of their bones. These calcium deposits allow the female birds to pull calcium from a specific source to lay eggs, rather than taking from the necessary bone mass. Female dinosaurs have also been found to have this phenomenon.
One of the most exciting finds that shows a behavioural connection between dinosaurs and birds is the discovery of “nesting” dinosaurs. These fossils have been found atop a nest full of eggs ready to hatch, and they have been found in a position much like what a bird who is nesting and protecting their eggs would look like. This suggests that. like birds, dinosaurs protected their young with their feathered arms.
“The argument now has become overwhelming that birds are not only directly descended from dinosaurs, but we can’t even tell anymore where to draw the line between birds and dinosaurs,” Currie said in his closing remarks. “We have step-by-step progression that’s not represented by almost any other animal known.”
So next time you’re playing with your pet dinosaur, listening to the song-dinosaurs sing, or eating roast dinosaur for dinner, remember that dinosaurs are alive!