Troodon no longer a valid genus: Latenivenatrix and Stenonychosaurus replace it

[ImADinosaurRARR]

http://www.heritagedaily.com/2017/08/dino-hips-discovery-unravels-species-riddle/116234
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2017-0031#.WYsIW1GGOUl
https://www.sciencedaily.com/releases/2017/08/170808145519.htm

I'm sorry if this is already been talked about, but I couldn't find it.

[Kaprosaurus]

Welp,goodbye Troodon! And welcone Latenivenatrix and Stenonychosaurus!

[Reptilia]

I think Troodon is still a valid genus, despite it may be a nomen dubium. What I understand is that T. formosus remains while T. inequalis is no longer considered a Troodon species, but the Stenonychosaurus genus is being resurrected instead. Latenivenatrix should be a whole different genus, a bigger troodontid. Am I wrong?

[BlueKrono]

So now which was the most intelligent dinosaur?

[Sim]

My understanding is Troodon is found to be an invalid genus, being based on a tooth that is not distinguishable at genus level.  There's been discussion about how this could be the case for Troodon for a long time, with movement towards this, and now it's happened.

The Dinosaur Park Formation specimens that had been considered to belong to Troodon are found to belong to two different troodontids:

1. Stenonychosaurus, which is found to be valid again.  It's somewhat nice to see Philip Currie being one of the authors that makes Stenonychosaurus valid again, since he was the one who made the unfortunate decision to make it a synonym of the tooth taxon Troodon back in 1987.  If it wasn't for this, I think the majority of troodontid figures would be labelled Stenonychosaurus, not Troodon!

2. The new genus Latenivenatrix.

It looks like if the large unnamed Alaskan "Troodon" species gets named, it won't be a species of Troodon, since Troodon is no longer valid.

[stargatedalek]

So now which was the most intelligent dinosaur?

It's always been corvids.

[Reptilia]

What happens in such cases? If the genus Troodon is no longer valid how the derived family name, Troodontidae, is to be considered?

[Lanthanotus]

Oh so that means my Invicta model just got its validity back

[Newt]

What happens in such cases? If the genus Troodon is no longer valid how the derived family name, Troodontidae, is to be considered?

It remains valid (though it's also possible someone will propose a replacement clade name for Troodontidae; names above genus level are not constrained by as many rules as genus-level and lower names). I can't quite recall an example, but I know such things have happened before.

[Halichoeres]

The paper explicitly retains the family name Troodontidae, and erects a new clade within it, Troodontinae, which is inexplicably defined as "the most inclusive clade including Gobivenator and Zanabazar." I think that should have been "least inclusive," because it seems to me that the most inclusive clade that includes those two would be All Life on Earth. Alternatively, they could have defined it as the most inclusive clade containing Zanabazar but not Sinornithoides, based on their tree.

They relegate Troodon to nomen dubium status pending further study or new specimens from the vicinity of the type locality, but the holotype isn't referred to Stenonychosaurus or anything.

@Sim: I agree it's nice to see that Currie himself is helping to amend all this troodontid taxonomy.

[SBell]

Oh so that means my Invicta model just got its validity back

But what happens to the few other Troodon figures? Like Geoworld or the Shapeways models? Which ones are they!?

[Sim]

I think Ceratopsia is like Troodontidae in the way that both group names are derived from a genus that isn't valid due to being based on inadequate remains, Ceratops and Troodon respectively.

Due to similarity of their teeth, before Troodon was thought to be theropod, it was thought to be an ornithischian, specifically the same animal as Stegoceras.  The family Troodontidae was then basically created for animals we now consider pachycephalosaurs.  When Troodon was found to be a type of theropod, this family was renamed Pachycephalosauridae.  Animals we now call troodontids that were known from better remains than Troodon, e.g. Stenonychosaurus and Saurornithoides, were classified in the family Saurornithoididae.  So the kind of dinosaurs we now call troodontids used to be called saurornithoidids.  This was the case until 1987 when Philip Currie synonymised Stenonychosaurus with Troodon, and Saurornithoididae with Troodontidae.  I would be quite happy with the family for these animals being Saurornithoididae again, if it happens.

[Mononykus]

But what happens to the few other Troodon figures? Like Geoworld or the Shapeways models? Which ones are they!?

I haven't looked at the actual paper yet (easier to download when I am at work than at home), but I would guess Stenonychosaurus would be the likely choice, since all the figures were made before Latenivenatrix was described (and L. is based at least partly on new material), plus the latter is larger (3.5 m vs 2.4 m) than is usually given for Troodon figures, which indicates most specimens previously used to characterize Troodon are probably now assigned to Stenonychosaurus

[Neosodon]

Troodon goes from one species with a simple two syllable name to two separate species with six syllable names. Hooray for scientific progress!

[Faelrin]

Just as I was getting into Troodon too. Ah well, this is science after all. Now I'm just wondering what I'll have to call the juvenile BotM one that's with the mountain accessory pack, since that was called Troodon formosus.

[Appalachiosaurus]

I don't understand why they can't just create a new Neotype like they did with Stegosaurus. Troodon seems to mainstream to be dumped in favor of a name 98% of the population can't pronounce.

EDIT: Oops. I didn't realize that the genus wasn't sunken, just made a nomen dubium, which is what I thought it was anyway.

[Pachyrhinosaurus]

Does this mean that anything later in age is still unpublished? I've heard about troodontids from upper Maastrichtian formations (maybe even Hell Creek, but I can't be sure).  Unless the teeth turned out to be acheroraptor, though they're different enough no one should have confused them if that's the case.

[stargatedalek]

This whole thing feels very pandering to me, it doesn't make the actual specimens any easier to understand or recognize. I would think Troodon is widely enough used to be a nomen protectum.

[Sim]

Does this mean that anything later in age is still unpublished? I've heard about troodontids from upper Maastrichtian formations (maybe even Hell Creek, but I can't be sure).  Unless the teeth turned out to be acheroraptor, though they're different enough no one should have confused them if that's the case.

It sounds like you're thinking of Pectinodon, which is a late Maastrichtian troodontid genus that was for some time another one considered a synonym of Troodon: https://en.wikipedia.org/wiki/Pectinodon

[WarrenJB]

Troodon no longer a valid genus

Nnnnoooooo!

Stenonychosaurus replace(s) it

Yissssssss...

Troodon seems to mainstream to be dumped in favor of a name 98% of the population can't pronounce.

I'd hazard 98% of the population would say "True-undone? Oh, it's a dinosaur. That's nice, dear." But on the topic of difficult-to-pronounce dinosaur names:

Troodon goes from one species with a simple two syllable name

Three. It used to have an umlaut: Troödon. I was going to link to youtube but I see that even the 'I'm a Dinosaur' vid on Troodon goes with 'troo-don' rather than 'tro-uh-don'.