Coelurosaurs facts for kids
Quick facts for kids Coelurosaurs |
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Coelurosauria
von Huene, 1914
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Coelurosaurs are a special group of theropod dinosaurs. They are more closely related to birds than to other large meat-eating dinosaurs like carnosaurs. This group includes many famous dinosaurs.
Some well-known coelurosaurs are tyrannosaurs and ornithomimosaurs. It also includes smaller dinosaurs like compsognathids. The group called maniraptors is also part of the coelurosaurs. Modern birds are the only living relatives of coelurosaurs today.
Scientists believe that all coelurosaurs likely had feathers. Many of them had long arms. They also had strong, hinge-like ankles. These ankles helped them move around easily. Over time, some of these features changed in later coelurosaurs, like birds.
Coelurosaurs also had bigger brains. The part of their brain for thinking, the cerebrum, grew larger. This trend continued as maniraptors and early birds evolved.
When Did Coelurosaurs Live?
The first signs of coelurosaurs are very old. Some fossil traces might go back to the Upper Triassic period. One possible early example is a creature called Protoavis. However, this is not fully confirmed. Fossils from between then and the late Jurassic are often broken.
Many complete coelurosaur fossils come from the late Jurassic period. For example, Archaeopteryx fossils are about 155 to 150 million years old. They were found in Solnhofen Limestone. Other dinosaurs like Ornitholestes and Coelurus fragilis are also from this time. They were found in the Morrison Formation in Wyoming. These fossils are about 150 million years old. Epidendrosaurus and Pedopenna were found in China. Their age is still being discussed, but they might be around 160 or 145 million years old.
Finding so many different fossils from the late Jurassic suggests something important. It means that coelurosaurs had already split into many different types before the Jurassic period ended.
In the early Cretaceous period, many amazing coelurosaur fossils were found. This includes early birds. They were discovered in the Yixian Formation in China. All the theropod dinosaurs found there are coelurosaurs. Many types of coelurosaurs lived until the end of the Cretaceous period. This was about 65 million years ago. Fossils of groups like the Tyrannosauroidea are best known from the late Cretaceous.
Most coelurosaur groups died out during the K/T extinction event. This was the event that wiped out most dinosaurs. Only the Neornithes (modern birds) survived. They continued to evolve into the many different kinds of birds we see today.
Most paleontologists agree that birds are direct descendants of coelurosaurs. Birds are often placed in the coelurosaur subgroup called Maniraptora.
Related Topics
See also
In Spanish: Coelurosauria para niños
