Jack Horner makes dinosaur species "extinct"

[BlueKrono]

I know TED Talks can be a little lengthy, but this one is pretty fascinating. After just a few minutes I couldn't stop watching. In it Jack Horner systematically eliminates several well-known dinosaur species. A must watch for anyone interested in dinosaur reconstruction.

https://www.ted.com/talks/jack_horner_shape_shifting_dinosaurs

[suspsy]

This is old news. The Triceratops=Torosaurus hypothesis has been shot down by a number of prominent palaeontologists now.

[MLMjp]

This is old news. The Triceratops=Torosaurus hypothesis has been shot down by a number of prominent palaeontologists now.

I have not wathced the video, but the first thing that came to my mind when I saw it was: Good old Horner is probably doing what he does best again.
And judging by your commentary. It seems I was right

[BlueKrono]

Yes, Torosaurud was the only one I was aware of before. But since that was pretty much confirmed a lot of companies have churned out misnamed pachycephalosaurs.

Suspy - I must be unfamiliar with Horner's reputation. What should I be aware of?

[Sim]

Even if the Triceratops/Torosaurus situation isn't clear yet, I think Jack Horner made some very good points in the video.  And the other growth series he mentioned in the video - Dracorex/Stygimoloch/Pachychephalosaurus, Edmontosaurus/Anatotitan, Tyrannosaurus/Nanotyrannus - are strongly supported by evidence.

I think Jack Horner is right that some dinosaurs have been named without giving enough thought to whether they are part of a growth series of another named species.  And that some named dinosaurs are probably specimens of another named species, just at different stages of growth.

[stargatedalek]

Everyone wants their moment in the limelight, so every new discovery with even a marginal chance of being distinct gets its own darn genus. Regardless of growth series, a lot of these animals really should be lumped at least at the genus level.




Seriously, we need to get whoever is in charge of lumping over at the IUCN to try their hand at some dinosaurs

[deanm]

  Those "hands" are the dinosaur taxonomists themselves - the IUCN is administrative body that effectively takes a request from a taxonomist and runs it through the beaurocratic process. 

[suspsy]

The Triceratops=Torosaurus hypothesis has never gained popularity outside of Horner and his grad student Scanella, although the others Sim mentioned are far more plausible.

[BlueKrono]

Is that so? He uses the exact same reasoning...

[Nanuqsaurus]

The Triceratops=Torosaurus hypothesis has never gained popularity outside of Horner and his grad student Scanella, although the others Sim mentioned are far more plausible.

The Nanotyrannus = Tyrannosaurus and Saurphaganax = Allosaurus make a lot of sense to me, but the Torosaurus= Triceratops doesn't really. Apparently there are Torosaurus subadults known. I'm by no means an expert on this topic, but wouldn't that rule out the fact that Torosaurus is a mature Triceratops?

[suspsy]

Is that so? He uses the exact same reasoning...

A Triceratops turning into a Torosaurus would involve faaaaaaaaar greater physical change than a juvenile T. rex maturing into an adult. Here, you can read a brief summary of Nicholas Longrich's debunking here:

http://www.bbc.com/news/science-environment-17192624

And here you can read Andrew Farke's entire paper that concludes Torosaurus is a valid genus:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0081608

[Soopairik]

Those are some good articles, supsy. I only read the second one but I will read the first one later.

[Reptilia]

I remember the Torosaurus/Triceratops, Stygimoloch/Pachycephalosaurus and Nanotyrannus/Tyrannosaurus thing, but was Allosaurus also involved in Horner's speculations? Moreover 8,5 meters seems a bit small as maximum size for an Allosaurus, wasn't it estimated to grow up to 10-11 meters?

[stargatedalek]

I remember the Torosaurus/Triceratops, Stygimoloch/Pachycephalosaurus and Nanotyrannus/Tyrannosaurus thing, but was Allosaurus also involved in Horner's speculations? Moreover 8,5 meters seems a bit small as maximum size for an Allosaurus, wasn't it estimated to grow up to 10-11 meters?

Quite the opposite, poor Allosaurus has been the victim of overambitious splitting and has had its dignity sold for profit. Comparatively marginal variations in size and brow crests have been considered enough to create several entirely new genera from, absolutely silly.  Compare these animals to those in say Orcinus, Basiliscus, or Ara, let alone an oversized taxa like Varanus, and these differences seem almost insignificant, or at least parallel, to species, subspecies, or even "regional variations" seen in modern animal taxonomy. Why should Saurophaganax be a genus distinct from Allosaurus (fragilis) when all those variations of Orcinus orca above aren't even deemed subspecies worthy?

To me, it just feels like another reason dinosaurs are often treated and seen as a vanity/publicity project even among the other sciences, and in cases like this I don't blame them. Giving dinosaurs their own genera primarily for the purpose of easier public recognition since they assume everyone is to much of an idiot to realize a genus can have more than one species is firstly insulting, secondly causes the problem to multiply because dumbing things down doesn't actually help people learn them, and thirdly devalues species level identification because "every cool dinosaur has its own genus name". And let's be honest here, that's what Saurophaganax is, it's a way to sell documentaries with "a new giant carnivore".

As for the chart I don't know where the measurements come from directly, sorry.

[BlueKrono]

Suspy - Do you think Horner would have been unaware of these studies? How can his data about bone density point to the conclusion he reached and still be incorrect?
Stargatedalek - At least the Pachyrhinosaurus species are differentiated at a species rather than genus level, and they have pretty different head ornamentation. The differences in the orcas are mostly coloration and soft tissue like fluke shape, features that wouldn't preserve as fossils, so it's understandable that they're all the same subspecies.
Reptilia - I always thought of Allosaurus as being about 12m long.

[suspsy]

Suspy - Do you think Horner would have been unaware of these studies?

Yes, because both Longrich's and Farke's studies came out long after Horner's, and his TED talk.

How can his data about bone density point to the conclusion he reached and still be incorrect?

Because he didn't take all available data into account and because a great deal of his hypothesis largely rests on the premise that since no juvenile Torosaurus fossils have been discovered, it must mean none existed. Which is a hopelessly flawed premise, as any Sherlock Holmes fan will happily inform you that absence of evidence does not equate evidence of absence. He also does not take into account (or ignores) the fact that the available adult Torosaurus fossils have been not been found in the same areas where the vast majority of Triceratops fossils are found. Or the fact that hole formation at an adult stage is not a normal part of ceratopsian maturation.

[Sim]

I was curious about what is actually known of Saurophaganax, and it seems its known remains are basically this?: http://lxblack.deviantart.com/art/Saurophaganax-2002-339842267

If so, that combined with how it coexisted with Allosaurus and how it apparently makes up one percent or less of the Morrison theropod fauna makes me wonder if Saurophaganax are actually individuals of Allosaurus that are rare due to being of great age.

[stargatedalek]

Stargatedalek - At least the Pachyrhinosaurus species are differentiated at a species rather than genus level, and they have pretty different head ornamentation. The differences in the orcas are mostly coloration and soft tissue like fluke shape, features that wouldn't preserve as fossils, so it's understandable that they're all the same subspecies.

The difference in size between Saurophaganax and A. fragilis is less than the difference between type A and type C orca, at least if you don't use conservative estimates for Allosaurus in reference to large estimates for Saurophaganax (as is often done to make it appear more impressive).

Because he didn't take all available data into account and because a great deal of his hypothesis largely rests on the premise that since no juvenile Torosaurus fossils have been discovered, it must mean none existed. Which is a hopelessly flawed premise, as any Sherlock Holmes fan will happily inform you that absence of evidence does not equate evidence of absence. He also does not take into account (or ignores) the fact that the available adult Torosaurus fossils have been not been found in the same areas where the vast majority of Triceratops fossils are found. Or the fact that hole formation at an adult stage is not a normal part of ceratopsian maturation.

Not saying I believe him, but there is a lot more to it than that. And you're incorrect about the fenestra, in most ceratopsians they appear as the animal ages and not from birth, and in some species don't appear until sexual maturity. Triceratops evolved via neoteny at some point regardless of whether or not Torosaurus was synonymous.

I recommend everyone reading the very well phrased response by the developers of Saurian on this topic:
http://saurian.maxmediacorp.com/?p=551

[Neosodon]

I don't think Jack Horner is a bad paleontologist but he gets a little to liberal with some of his theories. I watched one dicumentery were he claimed 1/3 of dinosaur species never existed which is a rather high estimate and in another he said T Rex was incapable of hunting live prey which has already been proven false by fossil discoveries.

[Takama]

I never really Took anything HE says seriously.  I find him more of a Attention Addict.  Which is why he worked with the Jp movies