Dont realy care as long as you dont say they were around only 6000 years ago.

 

Wait so there's no such thing as a Brontosaurus?

Huh. You learn new things everyday.

 

Same thing with Smurfs i here. tobe honest there were a lot of mistakes with a few paleontological studies. look at very early renditions.

 

It's pretty much consensus/fact that the majority of the coelurosaurs(a group including dinosaurs like Velociraptor and Tyrannosaurus and modern day birds) were feathered in some form or another. A select few disagree, but their claims have been thoroughly refuted. In fact, there's some speculation that this trait may have been ancestral to all dinosaurs+pterosaurs, but this is still up for discussion.

 

Going to have to redesignr Grimlock lol.
Nah i am quite aware of those facts.
whats every ones views on Mamle like reptiles?

 

I was of the mind that Pterodactyl could still refer to a group of "finger-winged" flying prehistoric creatures (think like bats), but not any one species. I could be wrong on that one though.

There's pretty solid evidence that at least SOME of them had feathers (like raptors and archeopteryx), but which specific ones were feathered is still in need of additional evidence in many cases. A lot of the dig sites in China have been great for learning new things and finding new species.

What I find REALLY interesting is the ongoing discoveries of similarities between "dinosaurs" and modern birds.

Mammals (I'm assuming that's what you were trying to spell?) and reptiles are very different things. What mammal-like reptiles are you referring to? There were dinosaurs/prehistoric reptiles that may have exhibited a few mammalian traits, like self-regulating body temperature (though really, I suppose in this case it would be closer to birds than mammals), and very early prehistoric mammals, but I've never heard of a "mammal reptile" I don't think.

 

Apparently today's birds are classified as dinosaurs. Dino's sure taste good  

 

about time a thread for us Dino fans!

 

He's probably referring to the synapsids, often called "mammal-like reptiles." Dimetrodon, for example:




Mammal-like reptiles | Natural History Museum


 

 

Yeah, that's what I was thinking too, but they weren't really mammalian in a lot the ways that Therapsids (and later "true" mammals) were.

 

This is true. The most primitive dinosaur known that DEFINITELY has feathers is Sciurumimus from the Late Jurassic of Germany. Sciurumimus ("squirrel mimic") is a baby megalasauroid with a bushy tail. Megalosaurs are slightly farther from birds than Allosaurus and kin, so early feathers go back at least that far along the dinosaur family tree. It is debated whether the bristles on the tail of the primitive ceratopsian Psittacosaurus as well as the the structures on the body of Tianyulong are primitive feathers or integumentary structures that evolved separately. Since the latter two examples are both ornithischians on the opposite side of the dinosaur family tree from birds, if they are feathers then all dinosaurs at least evolved from feathered ancestors. Even if all dinosaurs had feathered ancestors, no doubt many dinosaurs in warm or mild climates had sparse plumage. Kind of like how elephants, rhinos, hippos, babirusas, and even some bats have such sparse hair today.

 

Were you thinking about Cynodonts, like from Walking with Dinosaurs?

 

What's the current status of the Triceratops? Is it a Torosaur or its own separate species?

 

I believe you are referring to the Pterodactyloids, one of the two sub-orders of pterosaur. Pterodactyloids included such flyers as Pteranodon, Pteradactylus and Quetzalcoatlus and were defined from the other sub-order, the Rhamphorhynchoids, by their typically larger size, lack of long tails and the prominent crests amongst them.

The Rhamphorhynchoids were the smaller ones with the long tails, the Pterodactyloids were the bigger ones without tails, speaking generically. They didn't really co-exist, though; the latter was dying out near the Jurassic's end, leaving the former to take over as master of the ancient skies.

 

Triceratops is Triceratops. That never changed and will never change.

Torosaurus is in dispute depending on who you listen to. According to Jack Horner, Torosaurus is fully mature Triceratops. He also says Nanotyrannus is juvenile T.rex, and Dracorex and Stygimoloch are growth stages of Pachycephalosaurus.

... I'm not saying he's wrong, but I remember seeing an interview with him years ago where he said his theory was dinosaurs had been in decline before the final extinction, and that at the end of the late Cretaceous there was less diversity of dinosaur species than earlier. I have this at the back of my mind when, about a decade later he's putting out all these papers lumping one species into another, effectively reducing the amount of dinosaur variety at the end of the Cretaceous.

 

the evidence for feathered dinosaurs is indisputable. Although it took me a while to get used to the new look. But it opens up a lot of exciting possibilities for reconstructions. The big area of debate is how widespread it was, and how far back it goes.

I've seen that Psittacosaurus fossil, and in addition to the quills it should be noted that it has extensive scale impressions over the rest of the body. Whatever the quills were, they weren't insulation.

It shouldn't be overlooked that there is plenty of solid evidence for scaly ornithischians, it's just not clear if that's the full story.

 

Well I've seen pictures of the same specimen and it definitely has scales all over its body. My point was more the evidence of possible and definite feathers across various dinosaur clades rather than their particular function. Obviously those particular structures on Psittacosaurus's tail were NOT for insulation, but the possibility is always there that if ornithischians did have protofeathers that some did use them for insulation. Of course many ornithischians had scaly skin (hadrosaurs, ceratopsids, etc.). As did sauropods.

By the way, I am unconvinced that Torosaurus and Triceratops are the same animal. There are examples of both that are at the same stage of development in life based on the degree of cranial fusion. If the the theory is that Torosaurus is the fully mature Triceratops, then why are there torosaurs that were not adults when they died? To me they are separate animals.

I seriously doubt scaly ornithischians are the full story, regardless of whether the structures on Tianyulong and Psittacosaurus are homologous to theropod protofeathers or not.

 

Cynodonts are a subset of Therapsids.

I'm pretty sure, as others have described, that the evidence seems to be pointing at Torosaur being a life-stage of Triceratops.

Yeah, that sounds about right. Rhamphorhynchoids had "fingers" of their own aside from inside their wing structures, necessitating them not being Pterodactyloids, right?

 

I wasn't disagreeing with anything in your post.

The scales preserved in that Psittacosaurus are particularly nice, especially around the arms. You really get a sense of the animal.

You're probably aware of several other really well preserved scaly ornithiscians. There aren't many theropods, it tends to be a patch here or there, and I've never seen anything particularly impressive. Carnotaurus supposedly has scale impressions covering a substantial portion of the body, but it seems impossible to find pictures of this.

Torosaurus = Triceratops I don't really take a position on. There's already so much variety in Triceratops that no 2 skulls look all that much alike. There used to be about 20 species of Triceratops at one stage, but most of those are no longer recognised. I've seen some that definitely looked a lot like Torosaurus. Although it was also suggested that at least some of the Triceratops skulls in museum collections may actually be Torosaurus specimens with the frills reconstructed wrong.

 

Essentially. The Pterodactyloids had what was called metacarpals, long hand bones within their wings, a trait the more primitive Rhamphorrhynchoids lacked/didn't display much, another one of the key differences between the two orders. The Ptero's were pretty much the big tough evolved ones, and the Rham's were the scrawny sidekicks.


Also another meta word to add to my dictionary