1 in 3 Dino Species Never Existed?

Galvasean

A controversial study by Jack Horner suggests that as many as one third of all known dinosaur species have been misidentified and do not represent actual species, but are actually just younger versions of larger species.
You may remember Jack Horner from his documentary Valley of the T.rex, where he argued the case that Tyrannosaurus was a scavenger as opposed to a hunter. Although what the documentary did not show was the evidence (which had been well known to Horner beforehand, suggesting a lack of documentary ethics on his behalf) which went against and even disproved his theory.
So long story short, he's back (along with Mark Goodwin) with his latest major study, which has taken the best part of ten years (not to mention big bucks TV deal). Some of you may be disappointed to hear that Nanotyrannus may no longer be a valid genus, but rather a juvenille Tyrannosaurus:

The purported Nanotyrannus fossils have the look of a teenage T. rex, Horner said in the new documentary. That's because T. rex's skull changed dramatically as it grew, he said.

The skull morphed from an elongated shape to the more familiar, short snout and jaw, which could take in large quantities of food.

But the smoking gun, Horner said, was the discovery of a dinosaur between the size of an adult T. rex and Nanotyrannus.

Nanotyrannus—actually a young T. rex in Horner's view—had 17 lower-jaw teeth, and an adult T. rex had 12.

The midsize dinosaur had 14 lower-jaw teeth—suggesting that it was also a young T. rex, and that tyrannosaurs gradually traded their smaller, blade-like teeth for fewer bone-crushing grinders in adulthood

The evidence in this case is quite compelling, so it looks like Nanotyrannus will soon be stripped from the orthodox dinosaur genus list.

However, Horner and Goodwin's claims that 1 in 3 dinosaur species may not be valid has come under fire from other members of the palaeontological community. For example, Hans-Dieter Sues of the National Museum of Natural History in Washington D.C believes that their conclusions have been somewhat exaggerated.

National Geographic wrote:

"Many dinosaurs—just like many present-day vertebrates—changed a lot in their appearance as they grew up," he said.

But "some of [these] conclusions are controversial," Sues cautioned, adding that the idea that up to a third of all species may be reclassified is an exaggeration.

In fact, Sues suspects that a second wave of dinosaur extinction is unlikely—unless, that is, fossil hunters hit the jackpot.

"Testing such hypotheses is difficult," he said, because "it requires more fossil material than is currently available."

Just how much time will be given to those in opposition to the theory in the upcoming documentary remains to be seen, but based on Horner's last effort (Valley of the T.rex) there probably wont be much (if indeed any).

Full article here.

A juvenille T.rex, or is it a Nanotyrannus?

dlofnep

Was just about to post this.

Kess73

Feck off Horner. When I make my time machine I'll give you a chance to show me first hand that the T Rex is just a giant vulture.


And now he is picking on poor widdle Nano.

Galvasean

RE: the teeth argument. The case for Nanotyrannus being a juvenille Tyrannosaurus may not be as clear cut as the artice states if the case of another small tyrannosaur named Alioramus is anything to go by. Young Tarbosaurus (Tyrannosaurus' closest relative) had the same amount of teeth as adults. This fact made it clear that Alioramus was not a juvenille Tarbosaurus. The same could well be said for Nanotyrannus.

RichieO

I am frequently amazed at the amount of nonsense that is spouted by so-called experts, in many different areas, everything needs to be neatly pigeon-holed or categorized with no grey areas, what kind of people cannot see a predator doing the odd bit of scavenging, or accept the fossil record will NEVER be complete, or that some species lived and died without leaving a single fossil... The time scales and the fossilization process itself, automatically leaves massive gaps, that will always be a mystery to us and guarantee some errors...

Capt'n Midnight

OMG another mass extinction :eek:

http://www.sciencedaily.com/releases/2009/10/091031002314.htm

Unlike the original dinosaur die-off at the end of the Cretaceous period 65 million years ago, this loss of species is the result of a sustained effort by paleontologists to collect a full range of dinosaur fossils -- not just the big ones. Their work has provided dinosaur specimens of various ages, allowing computed tomography (CT) scans and tissue study of the growth stages of dinosaurs.

In fact, Horner suggests that one-third of all named dinosaur species may never have existed, but are merely different stages in the growth of other known dinosaurs.

scottie pippen

so would this be the same for many of the Tyannasauridae, particularly ones that co existed such as Daspletosaurus & Gorgosaurus (sorry my spelling my be off)

Galvasean

scottie pippen wrote: »

so would this be the same for many of the Tyannasauridae, particularly ones that co existed such as Daspletosaurus & Gorgosaurus (sorry my spelling my be off)

The name Gorgosaurus has been up in the air for a while now, with many believing it to be a species of Albertosaurus. If this is the case the name Albertosaurus would be kept since it was the first to be named.
As far as I know Daspletosaurus, as a name, is safe. Daspletosaurus was quite robust and is considered to be a very close relative of the later Tyrannosaurus (possibly even ancestral), while Albertosaurus (=Gorgosaurus?) was a comparatively more slender and gracile animal different enough to be worthy of a separate genus.

Galvasean

Mike Benton has weighed into the debate. He reckons more than half of named dinosaur species are mislabelled!
http://news.discovery.com/dinosaurs/dinosaurs-extinct-again-110517.html

Personally, I won't miss Dracorex hogwartsia. What a stupid crellboy of a name.

Wibbs

I'd throw in a few early hominids too. Especially a few of the leakey collected ones in Africa. A lot of "oh we found a tooth and half an inch of skull, must be a new species" going on.

Adam Khor

Wibbs wrote: »

I'd throw in a few early hominids too. Especially a few of the leakey collected ones in Africa. A lot of "oh we found a tooth and half an inch of skull, must be a new species" going on.

Agreed. Everyone wants to find the "missing link". Aren´t the Denisovans based on one finger bone or something like that?

Anyways, I wouldn´t trust Horner much- he has a long story of saying stupid things.
And, Dracorex may not have the best name ever but it looks very, very cool, so I really wish its its own genus >.<

Galvasean

Wibbs

Adam Khor wrote: »

Agreed. Everyone wants to find the "missing link". Aren´t the Denisovans based on one finger bone or something like that?

Yep, homo habilis is a stretch too. A lot of homo remains are. Their scarcity really doesn't help. The Georgian Erectus finds show a large difference between individuals. Hell look around on the bus and see same in moderns. In something as old as dinosaur families? All bets are off.

Adam Khor

Wibbs wrote: »

Yep, homo habilis is a stretch too. A lot of homo remains are. Their scarcity really doesn't help. The Georgian Erectus finds show a large difference between individuals. Hell look around on the bus and see same in moderns. In something as old as dinosaur families? All bets are off.

The Georgian erectus, is that the same as Homo georgicus? The one with the big canines?

Galvasean

Galvasean wrote: »

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

Fixed

Adam Khor

Wow he looks so old now

Galvasean

Well, he is 64.