Existed not so much dinosaur species as the science believe?

Yesterday i saw a TV film called the dinosaur code. In this film a scientist believe that dinosaur have a different look in the different phases of his life. So research shows that the same dinosaur can have looked completely different during his life. And so he think that some dinosaur species are only a other phase of the life and not a seperat specie.

That sounds for me plausible. What you think

http://www.n-tvnow.de/n-tv-dokumentation/der-dino-code.php?film_id=112033&player=1

It seems that there is some code on the site, and I can't see it   

But still, thankyou for raising the subject   

Could it be an idea to change the heading into something like " News about prehistoric animals " ?   

Well, back to the topic.
Even if I know very little about Dinos, I am sure they have already narrowed down some of the species, because they were just differnet ages.
That said, I am sure there were many, many more than we know now.
I would think that the major part of the dino species never left any fossiles.

Look at the African Savannah, how many gazelles there are, with minor differences between the species.
And think of how many, many years the dinos had to develop into different directions.

SUSANNE wrote:

It seems that there is some code on the site, and I can't see it   

But still, thankyou for raising the subject   

Could it be an idea to change the heading into something like " News about prehistoric animals " ?   

Well, back to the topic.
Even if I know very little about Dinos, I am sure they have already narrowed down some of the species, because they were just differnet ages.
That said, I am sure there were many, many more than we know now.
I would think that the major part of the dino species never left any fossiles.

Look at the African Savannah, how many gazelles there are, with minor differences between the species.
And think of how many, many years the dinos had to develop into different directions.

Yes, that was also a argument:)

It turned a very popular discussion when they started to think in torosaurus as an older stage of a triceratops, now there are several examples and also loads of misidentified dinosaurs or false positives intentionally created.
But Susanne is right, most part of them won't ever be discovered or identified once species can also be very similar and almost impossible to distinguish using only fossils.

Look an example her, of the problems connected to identifying species from ( partial) fossiles   



Source : DINOSAURS. The most complete, up-to-date encyclopedia for dinosaur lovers of all ages.

Maybe some skeletals are only showing the same dino species at different stage but, every months, new dinos are discovered and I agree with Susanne, there is no reasons to think that Jurassic wildlife was less  diverse than extant wild life.

This makes lot of sense, although this is silly to say that Torosaurus and Triceratops are the same: Triceratops has no fenestrations while Trorosaurus has big, wide ones. Those fenestrations would have developped a lot more slowly that that, right from childhood, if they were the same species. But Dracorex being a baby Pachycephalosaurus makes a lot of sense, because we have no other "baby Pachycephalosaurus" registrations in fossiles. Besides, when we look at baby owls, they look like baby eagles. Their eyes become more and more "facial" with age. The same kind of evolution certainly could have existed between a flat-headed baby Pacycephalosaurus and a round-headed adult Pachycephalosaurus.

I believe the name of the scientist is Jack Horner, of the documentary you are talking about Andreas. And it is an interesting topic. The version of the documentary I watched brought up how the knobby bony protrusions on the base of the skull for dracorex, pachycephalosaurus, as well as another species happen to be in the exam same arrangement. His argument for triceratops etc. refers to his cross sections of horn segments that indicate that the growth rings show different directional growth (horns grew upwards and or eventually began to turn downwards) and these match up with approximate sizes of different thought to be species of ceratopsian etc.; this was highly controversial since fossil specimens are considered valuable, so to cut one up is a loss of a potentially important specimen. (if any of that makes sense the way I put it...) etc. etc.

The statement of the documentary is that the speciation we recognize today would be at least halfed if not less, but something to keep in mind also is that fossilization is an incredibly rare event that requires an animal to die in the exact right spot with the exact right conditions for mineralization to occur. I can't remember the exact percentage, but something on the order of around 3% or less of the animals that have ever lived on this earth were fossilized. So there are likely TONS of species that weren't recorded in sediment let alone TONS MORE of specimens that have yet to be found by us.

Anyways, it is an interesting topic, especially to apply it to modern species as Susanne did above.

There is a lot of controversy on this topic, and most of it is not very supportive of Jack Horner.

Some, like the series of pachycephalosaurs, probably represents growth stages. Others require very convoluted explanations for how the different genera could really be the same

It's not my expertise, but Andrew Farke poked a lot of holes this suggestion--especially by properly describing Nedoceratops (the presence of which as another Triceratops was crucial to the still-poorly-supported hypothesis) as distinctly different.

I remember being very sceptical early on--and there really hasn't been any decent evidence that has changed many minds.

I'm not sure what I think either honestly, but in some cases it seems that it could be as you pointed out and probably not the case for others. Jack Horner has some interesting historical finds under his belt though, and honestly I don't think we can or will ever completely understand a past that is so far gone and so so different.

Saarlooswolfhound wrote:

I'm not sure what I think either honestly, but in some cases it seems that it could be as you pointed out and probably not the case for others. Jack Horner has some interesting historical finds under his belt though, and honestly I don't think we can or will ever completely understand a past that is so far gone and so so different.

As you say, he has some great work behind him--but a lot of his later work (not finds) has seriously impacted his reputation--insisting that T. rex was a scavenger (nonsense); his theoretical 'work' to use genetic manipulation to recapitulate a 'dinosaur' from a chicken (um, okay); and of course the recent work with Scanella to insist that there are far fewer genera/species of dinosaur than we think (often based on limited data, and mostly based on conjecture).

Plus, his 'marriage' so that a student could keep working with him or some such tomfoolery...that was weird.