Dromaeosaurs

Table of Contents

Section 1 — pages 2 and 3

Section 2 — page 4

Sect 3 — page 5

Sect 4 — page 6

Sect 5 — page 7

 

 

Section 1: Evolution

Birds are all over the planet in the modern day, just like Dromaeosaurs, better known as Raptors were in the Late Jurassic to Late Cretaceous.  Birds were also around by the late Cretaceous, and some Dromaeosaurs probably hunted them.  It is a common belief between paleontologists that Archaeopteryx, a Dromaeosaur from the late Jurassic evolved into birds.  Archaeopteryx was about the size of a raven with feathered wings like forearms and legs.  Also, its body was covered in short feathers and its tail had long feathers sprouting from its tail.  It could climb trees with its claws and glide from tree to tree using its front and back wings, its arms and legs.  Also, in the early Cretaceous, there was Microraptor, which was an iridescent black in color with wings like Archaeopteryx and a diamond-shaped fan on the end of its tail.  Like Archaeopteryx, Microraptor glided from tree to tree using its wings, but it is unclear if it flapped.  It ate small mammals, birds, fish, and lizards.  Its eye socket size indicates that Microraptor was nocturnal.

The later Dromeosaurs are presumed to be secondarily flightless.  This means they might have evolved from flying ancestors, maybe even Protoavis.  Protoavis was a bird before the Dromaeosaurs.  It had hollow bones and probably feathers and it lived in the Late Triassic.  This creates another bird evolution theory, that is, all birds evolved from Protoavis.  This would topple the birds evolved from dinosaurs theory if it is true.

The later Dromeosaurs like Velociraptor and Deinonychus evolution into birds is controversial since birds were already around at the same time,

The other birds in the Cretaceous came in many shapes and sizes.  Some even swam in water or soared over it, hunting fish.  Hesperornis resembled a four-foot long cormorant and swam in the warm shallow seas.  Guildavis was similar to a tern, diving into the water when it saw fish.

 

                 

 

Section 2: Fame and Media

Take the Velociraptor.  In Jurassic World, they were as big as the keeper, but in real life, they were a lot less threatening.

Once you look at that size comparison, you notice they are not that quite big.  Also, Velociraptor was covered in feathers.

The Utahraptor, the largest Dromaeosaur, was very large and threatening compared to the Velociraptor.  It was 20 feet long and 8 feet tall, making velociraptor look like a juicy chicken drumstick.  Utahraptor was featured in Raptor Red.  Deinonychus, which was a  little less than half the size of Utahraptor was featured in Jurassic Park and The Lost  World.

 

Section 3: Shapes, Embryos, and  Living Fossils

Many Dromaeosaurs had the same body shape as some birds such as corvids, raptors, thrushes, and pheasants.  All have a protruding chest and upright position, and heads, wings/arms, and tail connected in the same place.  The difference is that Dromaeosaurs have snouts with teeth instead of a beak and feathered arms with talons instead of wings.  Also, they had longer and more reptilian tails.

Some scientists study Embryology, which is the study of embryos.  This helps see more traits birds inherited from dinosaurs.  Scientists have made chicken embryos with dinosaur leg bones and snouts.

Hoatzin (Opisthocomus hoazin) chick has claws on its wings to grip and climb, Guyana

Hoatzins are a type of bird that lives in the Amazon jungle in trees along rivers and lakes.  The chicks are born with Archaeopteryx-like claws on their wings.  They use them to climb up trees.  When a predator attacks the nest, the Hoatzin babies drop from the trees and into the water.  Then they swim to the bank and climb back up the tree.

Touracos, another living fossil, also had clawed wings.  The juveniles use them to help climb before they can fly.

 

Section 4: Feathers and Flight

              Dromaeosaurs, very much like raptors had arms and sometimes legs feathered much like wings.  Also, Dromaeosaurs had a feathered reptilian tail.  The larger Dromaeosaurs, such as Utahraptor probably used feathers for warmth.  Also, the medium and smaller Dromaeosaurs probably used the feathers for bursts of speed.  Finally, the tiny Dromaeosaurs like Microraptor used the feathers for gliding, maybe even flapping.  All Dromaeosaurs probably had feathers, except in their face, beak, and feet. 

Birds have varied a lot since the extinction of the Dromaeosaurs and use their feathers in many different ways.  Large ground birds like the Ostrich use their feathers for showing off and hatching eggs.  Large flying birds use them for warmth and well, flying.  Skipping to the smaller ground birds like pheasants and grouse, they use feathers for warmth, speed, gliding, camouflage, and sometimes flapping, while small flying birds use them for warmth, camouflage and flapping.

 

Section 5: Conclusion

Dromaeosaurs and birds are differed and linked in many ways as time wears on.  Maybe there will be birds in the future in millions of years that do not slightly resemble Dromaeosaurs because of genetic variation.  It is amazing how living things have gone from sea to land to air — and thriving.  Birds and Dromaeosaurs are two similar and different animals in different times and the same places.  And maybe they are even the same animal, changing and evolving into ever new life forms, as the world revolves and spins on its axis.

          

 

 

8 months ago

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