Evolution of Birds

Scientists believe that modern birds are related to an ancient type of dinosaur. Birds and therapod dinosaurs are the only known animals to have a wishbone.

Tyrannosaurus Rex

The most famous and best documented of all dinosaurs. In 1990, paleontologists digging in South Dakota discovered a Tyrannosaurus fossil with 90% of it's bones. A fierce predator, it's funny to think it's actually closely related to birds of today such as chickens. However, evolution doesn't necessarily favour the biggest and strongest lifeforms. It's those lifeforms best adapted and able to re-adapt to a changing environment.

Small Dinosaurs

Not all dinosaurs were big. Some were small. Eoraptor and Compsognathus were about a foot tall. The first dinosaur fossils with structures that could be considered feathers were found in the 1990s. Other discoveries followed. By 2011 some studies were even suggesting that all dinosaurs had some type of feathery covering on at least some parts of their bodies—in much the same way that all mammals have hair but not all mammals are hairy.

"We have had to stretch the definition of the class of birds so as to include birds with teeth and birds with paw-like fore limbs and long tails. There is no evidence that Compsognathus possessed feathers; but, if it did, it would be hard indeed to say whether it should be called a reptilian bird or an avian reptile." - William Henry Huxley

Sinosauropteryx

In the 1990s, paleontologists found several fossils that showed dinosaurs with feathers. These included microraptor and Sinosauropteryx.

Hair, scales and feathers are all made of keratin. Feathers are believed to have begun as a hair like structure that branched off.

Sinornithosaurus

Why would these feathers be selected for? Well today birds use feathers in a variety of ways. Feathers keep birds warm, they display them for mating, they glide down from heights, they use them to propel themselves up trees. The feathers could've been selected for for any of these reasons and become useful in other ways thereafter.

There are different kinds of feathers and down feathers, the under layer for many birds or only feathers in chicks are extra fluffy to keep them warm. It's believed that long gliding feathers evolved from that.

https://youtu.be/hPLgfGX1I5Y

https://youtu.be/JMuzlEQz3uo

Archaeopteryx

The most well know example of a dinosaur with feathers is Archaeopteryx. It was discovered only two years after Darwin published origin of species.

Despite their small size, broad wings, and inferred ability to fly or glide, Archaeopteryx had more in common with other small dinosaurs than with modern birds. In particular, they shared the following features with small dinosaurs: jaws with sharp teeth, three fingers with claws, a long bony tail, and second toes ("killing claw").

https://youtu.be/QGR5yOrChMA

Conchraptor

One of the first and oldest therapods to trade in their teeth for beaks were the Conchraptors. Named for the reason that they're believed to have lived on crustaceans and mollusks.

Hoatzin

An interesting modern day bird that could represent a further transitional form is the Hoatzin of South America. The chicks of which have pronounced wing claws.

It's believed that most birds lost teeth because it was advantageous in making them lighter and faster.

https://youtu.be/0HytWfqWYUQ

Junglefowl

Modern chicken came from south Asian junglefowl. They were traded into Europe in the 16th century. People noticed that females lay 6 eggs and if removed they continue to lay. These junglefowl also had foot spurs for defense.

Chickens

As amusing as it is, Chickens are related to Tyrannosaurus Rex. Although the theory of evolution describes how everything is related birds are descendants of dinosaurs.

Chicken embryos grow teeth buds before they regress and abandon development. There have been rare reports of the teeth genes remaining on and chickens having teeth.

Ostrich, Moa, Emu, Kiwi, Cassowary branched of from birds. These birds lost the ability to fly when it no longer became necessary for survival.

https://youtu.be/0-7iXyYS0uw

Evolution of Flight 

Ostrich have wings, are they useless? 

If they were smaller, would they be able to fly with these wings?

https://youtu.be/8v-hA6oUSrE

Chickens related to Tyrannosaurus?

How ridicoulous?

 

Why is it that highly educated scientists are wrong but the average person can just use common sense?

 

Let’s think about it… What does it mean to say Chickens came from Dinosaurs?

 

Do scientists believe that T-Rex got smaller and smaller over the generations until it became a puny chicken? The theory of evolution only requires that something be more likely to survive long enough to reproduce. Therefore, if there were a selective advantage to being smaller, you might see the smaller T-Rex living longer than big T-Rex. However, T-Rex lived in the cretateous period, the period of the mass extinction. Big Dinosaurs didn’t survive this event, therefore there wouldn’t have been time for T-Rex to evolve.

 

That’s a huge flaw in the theory! 

If only it was what scientists believe. As a general rule, always ask scientists what they believe and don’t ask others to tell you what scientists believe.

 

However, scientists are well aware that T-Rex died out. When you look at scientific sources, they explain.

Therapods are a class of Dinosaurs that were two legged predators. T-rex is in this group but so is Compsognathus. 

Argument 1: Birds are warm blooded but dinosaurs are reptiles therefore cold blooded 

Not all reptiles are cold blooded. The Argentina Tegu lizard is warm blooded.