Could Jurassic Park actually be in your backyard? A velociraptor racing at you as you step out to your grill. A T. Rex thrusting at you from the shrubbery. A brontosaurus peeking into your kitchen window. It might not be so imaginary as you might think. There is a growing group of scientists who think that birds may actually be modern day dinosaurs!
They point to some amazing similarities between present day birds and those of dinosaurs. Of course, there are the characteristics shared by all vertebrates, for example, a backbone and a similar organ system structure. Reptiles include snakes, turtles, lizards and the extinct dinosaurs. These tough skinned reptiles have scales while the delicate skinned birds have feathers. But close examination reveals that feathers and scales are produced by similar tissue. Birds also have scales on their feet. Birds and reptiles lay eggs. The main basis for comparison is in skeletal similarities. Dinosaurs are extinct and are only known through fossil evidence. There are over 100 similarities found in bird and dinosaur skeletons. A list of some of these similar characteristics of early birds and a group of dinosaurs are as follows:
– Structure of the pelvis (hip) bones. One of the three bones that make up the pelvis, the Pubis, is orientated like a keel located in the back part of the hip. The back of the bone also has a boot-like appearance.
-The Sacrum, the part of the backbone that joins the hipbones, is make of five or more distinct vertebrates.
– The first birds had forelimbs that were elongated and ended in three-toed claws while their hind limbs had four toes. (With time modern day bird’s forelimb developed into wings).
– The wrists are flexible.
– The eye sockets are large.
– The bones tend to be hollow and thin-walled.
– Tails are short and stiff.
– The foot bone between the toes and ankle (metatarsals) are elongated.
– The neck forms a S-shaped curve.
– The skeletal structure indicated that the ankle is held off the ground (digitgrade) with feet positioned directly under body.
– Similar tooth structure.
-Shoulder bone structure alike and indication that movement of forelimbs were similar. The shoulder blade is narrow and the collar bone is fused into a “wishbone.”
– Two large openings found in the skull are shared by birds and dinosaur fossils.
– Recent dinosaur finds indicate the possibility that that they may have been covered with some kind of covering that may be similar to feathers. Other finds indicate that some dinosaurs may have been warm blooded like birds.
A flock of Canadian Geese, a solitary Cardinal or a pair of mourning doves offer a glimpse into a distant past when humans were not recorders of events. Dinosaurs may have been giants but indications are that they were relatives of the tiny birds of today. As modern day birds evolved the differences between bird and reptile became more explicit. Primitive birds, such as the kiwi, ostrich or emu, exhibit closer similarities to dinosaurs like velocipator. These three birds have more characteristics in common with ancient fossils than others and offer an insight into the evolution of the bird. Birds may well be the dinosaurs of today.
