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

Even if you ignore the fossil records, biology and genetics would still show you evolution. Did you know humans have a tail, its called a coccyx and its called a vestigial organ

Xenotaris

Yes, the fossil records, genetics, and biology shows us its true. Lions and Tigers can produce hybrids because they belong to the same genus Panthera which is a clade above species. However Ligers and Tigons can't produce offspring because they are hybrids from two different species of panthera.

Humans and Chimps can't bare offspring because we are from two different genus, let alone species.

Gmkgoji

Ugh, PLEASE don't bring up the Coccyx.

It's not vestigial, it is required to sit. Yes, you can survive without it, but you can also survive without eyes. Does that mean eyes are vestigial? I don't think so.

Xenotaris

Eyes have more of a purpose than the Coccyx, eyes would only be vestigial if you no longer need vision.

Xenotaris

Okay here are the main clades:

DOMAIN
KINGDOM
PHYLUM
CLASS
ORDER
FAMILY
GENUS
SPECIES

Gmkgoji

Uh huh.

What about them has evidence to support evolution?

Xenotaris

Simply it tells us where they came from I mean if creationism is real then Dogs, cats, Humans, and Trees shouldn't have similar traits to define them nor genetic structures to indicate they are related and should be considered ALIEN to the rest of all life!

Xenotaris

 Take big cats for example, the reason why they are placed under the genus of Panthera is because they all share alot of traits and their genetics agree that Lions (Panthera tigris), Leopards (Panthera pardus), Jaguars (Panthera onca), Tigers (Panthera tigris), and Snow Leopards (Panthera uncia) all came from a single common ancestor some ten million years ago.

What is not listed are all the extinct members of Panthera

Kamoebas V.6

So,this is the first time GmkGoji is from the minority.

Gmkgoji

Ah yes.

I see where you are getting at. 

While I believe that evolution is BS, I do believe in common ancestors that gradually adapted to their environment.

Gmkgoji

Yup. I'm in the minority, but don't give a crap

Xenotaris

If you believe that common ancestors existed then why do you have trouble believing that land vertebrates came from fish that slowly adapted to their environments and gradually became amphibians?

Kamoebas V.6

Ah yes,

I knew what you meant.

While i do believe that evolution is true,i do believe that you know a bunch of stuff.

Gmkgoji

I believe that all animals were created according TO THEIR KINDS. In short, all animals came from a common ancestor from their kind.

All fish come from a fish.

All Birds come from a bird.

But a Amphibian did NOT come from a Fish.

TheLazyFish

... Ok I'm a bit sad... no one, I MEAN NO ONE, has brought up the fact we've SEEN evolution happen, except me, and no one's talking about it. We've seen it happen. I mean, just watch the video! JESUS. Also... for the fish thing... it makes complete sense to me. In the time that fish evolved to move on land a bit more, swamps were much smaller and regularly ran out of oxygen, so the fish trapped within would die. If a fish evolved to belly flop a little from tiny puddle to tiny puddle, and to breathe air, then they'd survive despite the lack of oxygen in the water. Eventually, some evolved to be able to move on land more easily as to escape predators, take advantage of food sources, and the reasons listed above, which were the first amphibians. Due to still being close(ish)ly related to fish, they still, to this day, have to usually stay around water or their skin will dry out (like a fish). Eventually some took more and more advantage of land and eventually evolved to be completely independent from the water, and not needing to stay around them, which were the first reptiles. That's why fish evolved legs. Originally it was just paddles, like the lungfish today. I mean, we see Snakeheads do a similar thing today, so it really isn't far fetched.

Kamoebas V.6

I've seen evolution happen!But i didn't mention it.

Kamoebas V.6

And basically frogs are not born with legs,and when they evolve,they get legs,so GmkGoji,you are not right.

TheLazyFish

Also, define "kinds". Like just animal in general? Or fish in general? Or just from grouper to grouper? Also, if fish are so diverse and you admit they all evolved, and we see (even today!) fish that can somewhat move on land and breath air, what's so hard about those fins becoming full fledged limbs? And if it's true for fish, that should also be true for MAMMALS, where we've seen creatures evolve wings to become bats, and wolve like thing LOSE limbs to go into the water and become whales. So admitting that creatures can lose or reduce limbs to live in the water, what's to say the opposite isn't true? Also, technically you're right about kinds, because we're all defined as one big kind called ANIMALS. I mean, if a creature were to evolve for 5 billion years within its kind, then they would end up VERY different from the original kind, you know, like a fish to a bird?

TheLazyFish

Kamoebas, that's not evolution, that's ontogeny, where a creature simply changes as it grows older, like a baby looking a lot cuter and much more dramatic proportions compared to a human adult.

Gmkgoji

Oh, by the way...

I also believe that all KINDS of animals coexisted for a period of time.

Gmkgoji

All kinds, like, a specific group of animals. NOT species.

TheLazyFish

... That's not a definition. DEFINE it. Like in terms of birds, would it be different kinds of pigeons? Storks to cranes? Cassowaries to emus? Pelican to dove? Birds in general? DEFINE!

Gmkgoji

BIRDS IN GENERAL! NOT SPECIES! ALL BIRDS ARE BIRDS, ALL FISH ARE FISH, ISZZAT TOO HARD TO UNDERSTAND? AAAAAAAAAAAAARRRRRRRRRRRRRRRRRRGHHHHHHHHHHHHHHH 

TheLazyFish

It is when you don't specify. Ok so explain this: why are so many different groups so similar? Like an amphibian to a fish? Why do so many creatures possess the same, initial components? Why does every creature have DNA, if god created each group differently? Also, if he created each kind to do be a certain thing, then why do creatures of different kinds occupy the same niches, or creatures of the same kind occupying a bunch of different niches? Surely God created each kind for some, specific purpose?

Kamoebas V.6

I know that LazyFish,i just forgot what the word was,its was ontogeny,thanks for the reminder!

TheLazyFish

I mean, we could talk about it being evidence of evolution, but it's kinda minor and I don't want to get into specifics. It's also pretty complex, and I don't want to get into that. I mean, I have to live up to my name!

Gmkgoji

Nope. No purpose except to show the beauty of creation.

TheLazyFish

... Then every creature should be DRASTICALLY different. They really shouldn't be the same at all if that was the case!

Kamoebas V.6

YOU ARE FREAKING LAZY!

IM JUDGING YOU BY THE NAME!

Gmkgoji

Diversity is a moot point.

All creatures adapted to the environment they got stuck in after the great flood.