The Troodontid Thread

Adam Khor

Talos, new troodontid

I am loving the name; I used to be scared of Talos from Jason and the Argonauts as a kid

The new dinosaur is a troodontid, smaller than Troodon, that lived during the late Cretaceous in Utah, alongside Teratophoneus, Utahceratops and Kosmoceratops.

It is so named because the holotype seemingly succumbed to a foot injury, like the automaton Talos from Greek mythology.





http://www.livescience.com/16129-raptor-dinosaur-fossil-talon-weapon.html

Rubecula

Thanks for this Adam. Troodontids are fascinating things. (Even ones that look like an irritated turkey:pac:)

If they hadn't died out they could have been the fore runner of Sauro sapiens (I just made that word up)

Yep I find this almost as fascinating as marine reptiles, good stuff.:)

Galvasean

With the posting of Talos sampsoni, I was reminded that I forgot to post news of a new troodontid dinosaur called Linhevenator tani which lived in Inner Mongolia (which is, rather confusingly, actually located in China) during the late Cretaceous.

Compared to other troodontids, Linhevenator had a relatively long shoulder blade, a relatively short and thick humerus, and its second toe was tipped in a specialized, retractable claw like that seen in Troodon but not in some earlier members of the group. This is a curious suite of characteristics. Whereas Linhevenator appears to have had a killing claw similar to that of its dromaeosaurid cousins like Deinonychus, the newly described dinosaur may have had proportionally short and strongly muscled arms. This may hint that Linhevenator was not using its arms to capture prey in the same way as dromaeosaurids or earlier troodontid dinosaurs, even if it did have a specialized killing claw.

More.

Rubecula

Could it have been used in climbing?

Galvasean

That's one of the ideas put forward by the team. More research is needed before a solid theory can be made though.

Adam Khor

Rubecula wrote: »

Could it have been used in climbing?

I honestly can´t see troodontids as climbers... their forearms are too short and their legs too long. I think raptors (dromaeosaurs, cuz I don´t like using "raptor" for troodontids as well) are more likely to have been agile tree climbers- you know, having shorter legs and longer arms.

Galvasean

Troodontids do look more like runners to me as well. Very gracile legs and all that jazz. I can't think of any short armed climbers (snakes excluded who have none) off the top of my head.

Adam Khor

Galvasean wrote: »

Troodontids do look more like runners to me as well. Very gracile legs and all that jazz. I can't think of any short armed climbers (snakes excluded who have none) off the top of my head.

I can think of a few, like the pangolin or the silky anteater, but what matters is not the length of the arms but the length difference between arms and legs; I just can´t see how a long legged animal like a troodontid would be able to grasp branches or tree trunks with its very short arms- it would have to adopt very awkward postures .

Plus pangolins and anteaters have prehensile tails... which makes me wonder now if there were any dinosaurs with prehensile tails...

Rubecula

There is (or was, not sure if they still exist) a type of Kangaroo that climbs trees.

Adam Khor

Rubecula wrote: »

There is (or was, not sure if they still exist) a type of Kangaroo that climbs trees.

There is; it does exist. Actually, there are several species

Galvasean

Cute buggers..

Rubecula

Galvasean wrote: »

Cute buggers..

And very very tasty:pac:

They do look a bit like cuddly toys. However the reason I mentioned them originally was the tendancy of kangaroos to have disproportionate sized legs. Big at the back and not so big at the front. They climb trees. So I don't see that disproportionate legs stops a Troodontid from climbing. I am not saying they did, just that odd leg lengths does not automatically disqualify from doing so.

I am as probably as wrong as I usually am, just an idea is all.

Galvasean

Well from those pics posted the (adorable) tree kangaroos have fairly short legs similar in length to, if not shorter than, their arms.

Adam Khor

Galvasean wrote: »

Well from those pics posted the (adorable) tree kangaroos have fairly short legs similar in length to, if not shorter than, their arms.

I agree... you really can´t compare the disproportion between the tree kangaroo's legs and those of a troodontid. Most troodontids had VERY short arms and VERY long legs, just check this out:






Now check the tree kangaroo's skeleton:
http://family.webshots.com/photo/2326360540026680751tOglsC

Rubecula

It seems according to "Planet Dinosaur" that microraptor was a tree climber too. It had the raptor like big claw, and also extended fingers supposedly for getting grubs (much like the Aye Aye lemur)

Adam Khor

Rubecula wrote: »

It seems according to "Planet Dinosaur" that microraptor was a tree climber too. It had the raptor like big claw, and also extended fingers supposedly for getting grubs (much like the Aye Aye lemur)

That would be Epidendrosaurus, I think... the one with the very long fingers:

Rubecula

Yes you are probably right, but it did say microraptor on Planet Dinosaur.

I will step back from this as I don't actually know myself.

Adam Khor

Well, it really doesn´t matter, since both dinosaurs were seemingly tree dwellers.

Allosaur

Rubecula wrote: »

Thanks for this Adam. Troodontids are fascinating things. (Even ones that look like an irritated turkey:pac:)

If they hadn't died out they could have been the fore runner of Sauro sapiens (I just made that word up)

Yep I find this almost as fascinating as marine reptiles, good stuff.:)

It's now officially a word.

Rubecula

Allosaur wrote: »

It's now officially a word.

:pac: When I see it in Wikipedia I will believe it (or not as the case may be)

OMG. ROFL.

http://jamesvf.deviantart.com/art/Sauro-Sapien-148727783

Galvasean

Rubecula wrote: »

OMG. ROFL.

http://jamesvf.deviantart.com/art/Sauro-Sapien-148727783

If that's evolution, you can keep it..

Rubecula

Galvasean wrote: »

If that's evolution, you can keep it..

ditto

But it did have me choking on me cuppa. :pac:

Adam Khor

Second specimen of Mei Long, preserved basically in the same posture as the original:

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0045203

Galvasean

Interesting how it showed both juvenile and adult traits. I wonder if their growth was determined by food intake similar to a crocodile.

Adam Khor

Or that's what they think it is.

It is a feathered dinosaur but had less extensive feathering than other dinosaurs, with short fuzz in the tail and legs which allowed it to run fast (it also didn´t have the "killing claw" of later troodontids, apparently).

http://www.nature.com/ncomms/journal/v4/n1/full/ncomms2389.html

Rubecula

Great find Adam. I didn't know that such a thing was around in the Jurassic. Looking at the rendition I would have thought Cretaceous.

Adam Khor

https://experiment.com/projects/describing-the-first-jurassic-maniraptoran-dinosaur-from-north-america-a-new-find-in-the-morrison-formation-of-wyoming

Manach

Interesting news. As well the concept of the site, to fund scientific experiments, seems a good idea.

Adam Khor

http://www.sci-news.com/paleontology/albertavenator-curriei-05048.html
Not sure if it couldn´t just be a new species of Troodon, really.

Rubecula

artist impression is very very birdlike, more so than usual troodon images.

Adam Khor

Most paleoartists restore maniraptorans like this nowadays (and are quick to crucify those who don´t!)

Rubecula

I don't because I can't.

Adam Khor

Draw, or crucify?

Adam Khor

This new study describes two new troodontids (Latenivenatrix and the resurrected Stenonychosaurus) from what was believed to be Troodon remains. Troodon itself may become invalid after all. Latenivenatrix is notable for being perhaps the largest troodontid known to date.
https://phys.org/news/2017-08-dino-hips-discovery-unravels-species.html

Adam Khor

About 47 days, according to this study:

https://www.nature.com/articles/s41598-018-30085-6




Compare to the incubation period for some modern egg-laying reptiles:

Leatherback turtle: 60 days
American alligator: 65 days
King cobra: 60-70 days
Gharial: 60-80 days
Saltwater crocodile: 80 days
Reticulated python: 84 days
Marine iguana: 89-120 days
Galapagos tortoise: 4-8 months
Komodo dragon: 220 days (average)
Tuatara: Up to 15 months

And large birds:

Sandhill crane: 32 days
Rhea: 36-38 days
Ostrich: 42 days
Andean condor: 54-58 days
Harpy eagle: 56 days
Emu: 50-60 days
Cassowary: 60 days
Wandering albatross: 78 days

Adam Khor

Hesperornithoides, a Jurassic troodontid.

Based on a specimen known as "Lori", this small trodoontid would've lived under the shadow of the giant diplodocid known as Supersaurus. It is the oldest known troodontid from North America (the last members of the family were among the last non-avian dinosaurs to go extinct at the end of the Cretaceous).

https://www.smithsonianmag.com/science-nature/discovery-raptor-dinosaur-adds-new-wrinkle-origin-birds-180972588/?fbclid=IwAR1pjHt279vSA5VEeZarRgQMp9dB84bN9zWEe7UQBoXK3aWGweBSjHK0Ih0#yZ2vWavRW6zI5qEh.01