Dinosaur Evolution: A Journey from Tetrapod to Bird

Xenotaris

Okay before I get in to direct Dinosaur evolution I must first weave the tale of how these guys came along, okay lets start with the Fish that crawled out of the water otherwise it would be a drag explaining the evolution of fish.

Okay along time ago back around the Devonian time, a group of Lobe-fin fishes gradually evolved lungs and slowly crawled out of the water on to land to possibly escape from hungry predators.

These fish became the first Tetrapods or Amphibians, millions of years later and millions of generations later prototreptile amniotes then evolve from Reptiliomorph amphibians during the Carboniferous peroid, officially around the Pennsylvanian Epoch but it is possible they could of appear in the Mississippian epoch.

Animotes later diverged in to two clades: Synapsids (Mammal-like Reptiles and later Mammals) and Sauropsida (Classic Reptiles).

Now since we are going in to later dinosaur evolution we can mark out the Synapsids from the discussion since that would be a topic for a later time.

Sauropsida is then divided into Parareptilia (at the side of reptiles) and Eureptilia (True Reptiles)

Eureptilia later gives rise to several lizard-like early reptiles and then the clade Romeriida evolves which will give rise to Diapsid reptiles (Modern Reptiles and their extinct relatives)

Diapsid Reptiles would evolve in to several primitive forms before two notable clades would eventually win out so to speak. Lepidosauromorphs (Snakes, lizards, Tuatara, and their extinct relatives like mosasurus) and Archosauromorphs (Ruing Reptiles). Pantestudines in my opinion belongs with Archosauromorph due to DNA and Fossil record backing. This ends the Permian peroid.

Archosauromorphs, now where getting closer. After several basal clades we finally get Archosauriformes. Most Archosauriformes roughly resembled crocodiles if more lightly armored to barely armored but lets flash forward to the clade of Archosauria; seeing as the other Archosauriformes are no long relevant to this topic. Which happens mostly in the Early Triassic.

Archosauria can be divided in to two super clades: Avemetatarsalia/Ornithodira and Pseudosuchia (Crocodilans and their extinct relatives like the Rauisuchians)

Avemetatarsalia also known as Ornithodira or Pan-Aves is the clade that holds the Pterosauromorphs and the Dinosauromorphs.

Dinosauromorphs clade contains all Dinosaur clades including modern birds and their extinct relatives. Dinosauromorphs that were closer related to true Dinosaurs were Dinosauriformes while Non-dinosaurian dinosaurmorphs belong to Lagerpetids.

Dinosauriformes housed several dinosaur-like forerunners but the most developed group besides the dinosaurs themselves were the Silesaurids. These creatures appeared roughly in the Middle Triassic.

And now we finally arrived to the clade Dinosauria which itself is broken up in to two major clades: Ornithischia (Bird-hip Dinosaurs) and Saurischia (Lizard-hip Dinosaurs) both arrived in the Late Triassic.

Ornithischia can be splitted up in to three primary clades: Ornithopods (basically beaked bipeds and duckbills), Thyreophora (Plated and armored dinosaurs with attack tails), and Marginocephalia (Head Armored Dinosaurs)

Saurischia is simply divided in to two clades: Sauropodomorphs (Long Necked herbivores) and Theropods (Bipedal Carnivores, later some beaked long necked bipedal herbivores, and birds)

The earliest members of Saurischia were fairly theropod-like but we do know the earliest members of each clade. Eoraptor long suspected to be a primitive theropod or even a basal Saurischia is now thought to be a primitive sauropodomorph along with the similar Guaibasaurids while Eodromaeus snags the spot of the Eoraptors previous position as an early theropod along side the slightly more advanced Herrerasaurids.

Xenotaris

Hey everybody, I'm returning to finish this project!

Xenotaris

Okay now I'm returning

Kattozilla

I like birds

They're cool and pretty

Owls are SOME of my favorites, along with titmice, emus, parrots, etc.

Xenotaris

I love birds too, especially the Eagles

Xenotaris

Dilophosaurids were originally considered Coelophysoidea for a long time before fossil evidence showed they were actually more advanced and closer to Tetanurae theropods rather than Coelophysis. The Dilophosaurids' closely related members were Liliensternus liliensterni and Zupaysaurus rougieri and may have been sister clades to Dilophosauridae.

Now Dilophosauridae pretty much had only two members in it:

Dilophosaurus wetherilli

Dracovenator regenti

Former members like Cryolophosaurus ellioti and Sinosaurus triassicus have since been reclassified as basal Tetanurae

Gmkgoji

How do you know evolution is true? Give me some evidence

Kamoebas V.6

GmkGoji,

Do you think that somebody created earth?I don't,the evidence is that some tiny cells have evolved and became bigger,and for Dinosaurs...yes they did evolve,and simply,if Rodan existed,will he only be a bird?Wont he evolve and become stronger?There isn't evidence that someone created the planet!But its your opinion,if you don't think that evolution is true,well thats your opinion.

Gmkgoji

Well... I do believe someone created the Earth.

Also, how do you know that the cells "evolved" into bigger organisms?

Also, I do believe in micro-evolution. That animals adapt to their environment. BUT, I don't believe that a fish could turn into a bird.

TheLazyFish

Well, admitting micro evolution is true means that macro evolution is true, because it’s just multiple cells doing it at once. And because of how cells are formed and DNA, that’s easily possible. Besides, you have to believe in mutations. Evolution, essentially, is just a mutation forming, and if it is beneficial the creature with that trait will be more likely to survive and reproduce, and so that trait is more common over time across the population. Then more mutations over time happen, until the point it can no longer breed with the initial species it stemmed from and is a new species. Also, if someone created every species at once, then why are so many so similar, and they all have a similar body plan and structure (basically)? Shouldn’t they all be each more different than the last?

Gmkgoji

So... a amphibian can mutate to have wings?

TheLazyFish

Not BIG mutations like that. I meant a mutation in one specific part of the DNA. To evolve wings, that would take a great number of mutations over time to create functional wings. However, it's theoretically possible. I mean, if it was somehow an advantage, then over the course of millions of years some species of amphibians could evolve to have wings, yes.

Also, before you say something like: "We've never SEEN evolution happen!" I'd like to refer you to this:

https://www.youtube.com/watch?v=NArlXzSFt2Y

Also these for good measure:

https://www.youtube.com/watch?v=dfQuDKgwDTo

https://www.youtube.com/watch?v=OuqFUdqNYhg

https://www.youtube.com/watch?v=hOfRN0KihOU

https://www.youtube.com/watch?v=P3GagfbA2vo

Xenotaris

Well said, TheLazyFish

Gmkgoji

Saying that Micro-evolution means Macro-evolution is true is not a viable explanation that Macro-evolution is true.

Also, saying that a species develops over time through mutations is seriously wack. 

Take for example, the Bombadeer beetle. It shoots flammable substances comprisied of special chemicals to deter predators. How on Earth would many, small, random mutations be able to make a Bombadeer beetle have a incredible survival mechanism like this?

The beetle has four chemicals. Two, which mix together and EXPLODE. But, the beetle does NOT want that to happen inside his own body. So, the beetle has ANOTHER chemical which dilutes both chemicals. The fourth neutralizes the third chemical, which allows for 200 degree liquid chemical spray!

How does a bunch of small, random mutations cause such a complex and amazing animal? Especially on the scale of an insect? I'm fine with debating more, just tell me what you guys think. It's a 2v1! Or a 1v3? I dunno. 

Kamoebas V.6

Nobody created and evolution does not exist!

DOES THAT MAKE SENSE!!?!??!

Xenotaris

Gmkgoji its called Natural Selection, Speciation, and Genetic Drift. As for the Bombadeer Beetle, simply for generations a basal beetle feed on plants or materials holding those chemical compounds then through evolution gradually developed that survival mechanism to its modern form.

Curious you used the bombadeer beetle and not dispute my evolution chart of how Fish became amphibians to basal reptiles to dinosaurs to birds

Gmkgoji

Does a fish grow legs and walk on land? 

Eh, I don't think so

Kamoebas V.6

Welp,from that information,do you believe in god?I don't,because there is no proof that he exists.But there is proof that evolution exists,looks like no one created earth...

Xenotaris

Typical Creationist comeback, no a fish doesn't simply grow legs.

The fish that all backbone land animals evolved from were the lobed fin fishes, their only surviving members are the Lungfish and the Coelacanths. The linage of Lobefin fishes we came from were called Tetrapodomoprhs, they advent of lung devalopment started when oxygen levels in the water were depleting and the oxygen in the air became breathable for vertebrates. So through natural selection the swim bladder slowly developed into lungs.

So now the early tetrapodomorphs would slowly crawl up on land with their fleshy fins, Lobefin fishes have finger bones in their fins unlike Rayfin fishes. The lobefins slowly started developing into more finger-like structures as millions of years and a shit ton of generations of lobefin fishes having sex and producing offspring to carry these mutations. 

TheLazyFish

... I feel like everyone ignored the videos I posted... I'd be fine with that if the first one wasn't so important...

Gmkgoji

YAAAAAAAAWWWWWWWWWWWWWn...

Can we all agree to disagree? 

Or maybe argue about what killed most of the dinosaurs?

Kamoebas V.6

Which video

Kamoebas V.6

Ah yes,

ENSLAVED VIDEOS WHICH TELL US EVOLUTION!

TheLazyFish

Honestly the first link was most important... because it talks about instances where we've seen evolution happen over the course of a few decades, a process called rapid evolution. It brings up 3 fascinating instances of this.

Xenotaris

 Gmkgoji this is a topic about Dinosaur EVOLUTION so evolution is the main topic here. There is too much evidence to support Evolution (Genetics, Domestication, Medical science, basic understandings of Biology, and most importantly the Fossil Records) to be simply dismissed as a agree to disagree.

Xenotaris

Our understanding of evolution grows more and more with each new fossil discovered

Gmkgoji

The fossil record does NOT show evolution

Xenotaris

Hell just look at your individual human, you may have people with enlarge hearts or enlarge kidneys and the medical problems that go with them. if humans were created equally by a creator how come Humans and by extension all life come in all shapes and sizes, hmmmm?

At a creationist stand it doesn't really make and sense outside oh God made you that way just because. So God dilbertly made you born a cripple or dilbertly made you prone to heart attacks, I thought we were all created equally?

At an Evolution stand point, which you can still believe in God by the way, just not creationism. The reason why everyone is different and not equal is because these difference are supposed to allow us to thrive in different environments as well as weed out the less suitable ones. This applies to survival situations if we didn't have civilizations, the advent of Civilization removed humans from most of these natural pressures.

Xenotaris

GMK the fossil records does if you know to read clades

Kamoebas V.6

IT SHOWS THAT EVOLUTION EXISTS!

I DON'T CARE WHAT PEOPLE SAY!

EVOLUTION IS TRUE!

NOBODY CREATED EARTH!

Gmkgoji

Well how do you know the clades are true? You said it yourself, it is BELIEVED to be true.