Modern Dinosaurs Living Among Us
Dinosauria, whose name is derived from the Greek words meaning "terrible lizard", is actually not really a lizard in today’s sense of the word. They were actually a completely distinct yet diverse group of animals which dominated the planet for nearly 200 million years from the Triassic to the Cretaceous era. A suborder of Dinosauria, known as theropoda, is known to survive to this very day. Back when dinosaurs ruled the Earth, therapods consisted of some of the meanest, most ravenous carnivores. Their descendants today consist of modern birds. A new scientific study published recently shows just how remarkably similar today’s birds are with their prehistoric ancestors.
It can be difficult to believe that a common sparrow can be compared with a Tyrannosaurus Rex or a Velociraptor. Yet the similarities can be found throughout, from the head to the toes. But how could they evolve into a creature so much smaller?
According to the researchers, the answer lies in evolutionary changes in the sexual development of the dinosaurs. Normally, dinosaurs would take years to reach sexual maturity, allowing them ample time to grow. Due to external forces, they evolved to a speed up their sexual maturity.
Modern day birds, for instance, reach sexual maturity in as little as 12 weeks. This sped-up life cycle development allows modern birds to retain the physical characteristics of baby dinosaurs.
Today, birds are widespread throughout all corners of the world. There are nearly 10,000 species and are the most commonly seen wildlife. Due to their success, it may be fair to say that dinosaurs still rule the earth.
"What is interesting about this research is the way it illustrates evolution as a developmental phenomenon," said Arkhat Abzhanov, Associate Professor of Organismic and Evolutionary Biology and co-author . "By changing the developmental biology in early species, nature has produced the modern bird — an entirely new creature — and one that, with approximately 10,000 species, is today the most successful group of land vertebrates on the planet."
Reaching their conclusion was not intuitive. For example the skulls of modern birds and prehistoric therapods are vastly different. Therapods had long snouts and many sharp teeth while birds have beaks and larger eyes and brains. However, bird skulls compared with baby dinosaurs were remarkably similar.
The evolutionary change in their development cycle allowed birds to appear as baby dinosaurs deep into adulthood. Of course, since dinosaurs went "extinct" many other changes were forced upon the group of species such as growing feathers and taking flight.
So next time you see a cardinal or blue jay fly through your backyard, keep in mind that at one point in time, it was one of the feared creatures in all the land.
This study has been published in the journal, Nature
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