A New Middle Jurassic Allosauroid
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This episode is brought to you by Colorado Northwestern Community College. Join them for two weeks digging up dinosaur bones from the Jurassic period in northwest Colorado this summer. For details, go to cncc.edu slash dino dig. Hello and welcome to I Know Dino. I'm Garrett. And I'm Sabrina. And today in our 536th episode, we're talking about a new carnivorous dinosaur.

Yes, Yuan Mo Raptor, though it's not a raptor. Is it a mega raptor at least? No. Okay, well, we can talk about it later.

We also have dinosaur of the day, Chilescus, a Tyrannosauroid that may have had a crest. And there may or may not be a link between our dinosaur of the day and the new dinosaur. Oh, maybe it's a Tyrannosauroid. I guess we'll find out. And for our fun fact, we have that there are probably no Paleocene dinosaurs. Probably? Yeah. Excluding birds? Well, I mean, if you're going to bring birds into it. Well, I was thinking maybe that was what made it probably. Probably.

It's more following up on another fun fact we did a while ago about potential Paleocene dinosaurs. Oh, ones that just snuck by the asteroid impact for a little bit before going extinct? Mm-hmm. Gotcha. Unfortunately, we have a little bit of sad news. There was a death in the family. So apologies that this is a shorter episode. Next week, we will have a longer episode, I promise. So you will get a longer dinosaur fix.

Yes. So we appreciate your understanding and we hope you enjoy this episode. Yes. And if you want, if you're looking for something to do, you can always listen to an older episode. And if there's something in it that sounds interesting to you that you want to follow up on or something like that, you can send us a message at bit.ly slash dino questions and we might share it on our show.

But before we get into the main content, of course, we want to thank some of our patrons. And this week we have six new patrons to thank. And then we'll finally be caught up with all the patrons that were waiting patiently for all those weeks and even months to be thanked. Oh, yes. Thank you for your patience. And this week we'd like to thank Dale, Pablo, Scoobadoo, Carno Georgis, Jessica, and Taylor.

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Jumping into the news, as Garrett mentioned, there's a new dinosaur. It's a new carnivorous metriacanthosaurid called Yuanmo Raptor, specifically Yuanmo Raptor dinsha jiangensis. And this was published in PeerJ by Itso and others. Now, like I said, it's not a raptor or dromaeosaurid if you want to be a bit more technical.

It's a metriacanthosaurid, and metriacanthosauridae means moderately spined lizards. They're theropods. They're mostly medium and large size, and they lived in the Middle Jurassic to Early Cretaceous in Laurasia, the Northern Hemisphere. Mostly they've been found in China, Thailand, and England. Metriacanthosaurids are a group within Alloceroidea, although there's debate about where exactly they fit.

Yeah, Metriacanthosaurus for some reason comes up periodically. I don't know why, but that's one that I'm more familiar with of the rando allosauroids. Maybe because it's pretty big, although it's not really that big. It's roughly 8 meters or 26 feet long, weighing about a ton. But that is pretty big for a late Jurassic predator, which is what it is. Not too far off in time from Allosaurus proper.

which was in the same sort of ballpark. Yes. And like you said, they're both allosauroids. Yes. Well, Yuanmo Raptor was a little bit earlier, lived in the middle Jurassic, and it was found in what's now Yunnan province in China in the Jianghe Formation.

The genus name Yuanmo raptor refers to Yuanmo County where the fossils were found. So it's Yuanmo thief, raptor thief. So they didn't give any reason for why they picked raptor. Not that I could find. But the species name Jinsha Jiangensis refers to the Jinsha River, which is the middle part of the Yangtze River, which passes through Yuanmo County. These fossils were found or they were excavated back in March of 2006.

And they were in an area that's now surrounded by farmland. They found the relatively complete skull with lower jaws and part of the neck and back. It's a complete series of neck bones, and then you've got the first backbone. So there's 10 neck vertebrae. The skull is about 60 centimeters long or almost 24 inches, so a pretty good size, especially for a middle Jurassic. Pretty good. Yeah, I mean, I guess it's before Metriacanthosaurus. I think Metriacanthosaurus was like

three feet, 80 centimeters long type range. Well, for Yuanmo Raptor, there's some fusions in the bones that show that it was a sub-adult or nearly mature. And it's got some unique features in the skull and neck bones, like details such as air sacs or projections on the bones and different twists and depths and things that you have to have a trained eye to see, I think. Yeah.

But you can see the fossils on display at the Museum of Lufang World Dinosaur Valley in Lufang City, Yunnan Province, which is pretty cool that they're on display. Yeah, I like it when dinosaurs are discovered and there's a press release that goes with them. And there's also a place you can go see them in real life.

I used to have notes on what I like to talk about when new dinosaurs came out. And the last thing was always where you can go see this fossil. But so infrequently, were you actually able to go see the fossil somewhere? I don't even look for it anymore most of the time. But it's really cool when you can. And we'll get to our other theropod, the dinosaur of the day, in just a moment. But first, we're going to take a quick break for our sponsors.

This episode is brought to you by Colorado Northwestern Community College, CNCC. Time is running out to join CNCC this summer digging up and preparing dinosaur bones.

That means it's your last chance to sign up to help excavate amazing Jurassic dinosaurs like Allosaurus, Diplodocus, and Gargoylosaurus, an Ankylosaur. Of course, you bring up the Gargoylosaurus. Yes. Technically, it could be relatives of those because they still need to be excavated and prepared, so we don't know the exact genus yet for all of them. But when else will you have a chance to help excavate those amazing dinosaurs and help people figure out exactly what they are?

If you're not a camping type and you don't want to get out in the field, you can still get your hands on dinosaur bones by helping to prepare fossils in the lab. Or if you're really looking for a good summer, you can do both. A paleo summer. Yeah. Yes. The programs fill up quickly, so make sure you sign up as soon as possible.

This is probably the last time you'll hear us talk about the CNCC programs before the deadline, so make sure to get your spot now. And the team at CNCC, they really know their stuff, and they have access to dig sites that you can't get to on your own. So head over to cncc.edu slash dino dig. You'll get all the details. Make sure you register online by May 31st so you don't miss out. Again, that's cncc.edu slash dino dig.

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And now on to our dinosaur of the day, Kileskis, which was a request from Tyrant King via our Patreon and Discord. So thanks.

Keleskis was a Tyrannosauroid theropod, so that's the connection between our dinosaur of the day and the new dinosaur, Yuanmo-Raptor. They're both theropods. Anyway, Keleskis was a Tyrannosauroid that lived in the Middle Jurassic in what is now the Etat Formation in Russia, in western Siberia. It looked kind of like Dilophosaurus. Hmm.

Like it walked on two legs. It had a long face. It probably had a crest on its head, but just one, not two. Maybe more like Monolophosaurus then. Maybe, yeah. And it's actually unclear if it had a crest on its head. That's just an inference based on it being really similar to...

Proceratosaurus, which I felt like Dilophosaurus people have a better image in their heads of what that might look like compared to Proceratosaurus, but really it looked more like Proceratosaurus. Okay. I think Proceratosaurus, from what I remember, had sort of a smaller bump and it was farther forward on its snout. Yeah. Yeah.

So this one might have, but it's, again, we don't know if it had a crest at all because we just don't have those bones. Yeah. Although looking at Poroceratosaurus, I don't know how well the top of the head is preserved. So that might be a little bit of inference on where the actual top of the head ornamentation was. Just like with Dilophosaurus, that even took a long time to figure out. It did.

But the bones of Keleskis in the jaw are similar to Proceratosaurus. So that's where we get that comparison. And Proceratosaurus was a carnivorous theropod. It had a long head with the crest on top that started from the nasal. And it lived in the Middle Jurassic in what's now England versus Keleskis lived in the Middle Jurassic in what's now Russia.

Kieluscus also had long nostrils, and it's estimated to be about the whole body, 17 feet or 5.2 meters long, and weigh about 1,540 pounds or 700 kilograms.

The fossils found of Kuleskis include jaw bones and then a few bones from the hand and foot. So a lot of inferences have to be made. It's cool to find hand and foot bones, though. You often don't get those. And jaws aren't bad either. Yeah. And then there was a paper in 2019 that described even more Kuleskis bones, including neck and tail bones and a leg bone, fibula. So more of the puzzle pieces came in. And they found that Kuleskis grew more slowly than large Tyrannosaurids. Yeah.

That makes sense, considering it was not that big. Yeah. And that it was from way earlier. Yes. In the middle Jurassic. It does make sense. Kind of a middle Jurassic episode. That's something that connects the two. Oh, there we go. That's probably better than theropod. Yeah. Well, the type and only species is Chilescus aristotocus.

It was named in 2010 by Averinov and others. The genus name, Kuleskis, means lizard in the Caucasus language. Oh, cool. Yeah. And the species name, Aristotokos, means of noble origin. And it alludes to the dinosaur being one of the oldest known members of Salurosauria and Tyrannosauridae. That is cool. The group that eventually became Tyrannosaurus and also birds, if you're talking about Salurosaurus.

Yes, and other dinosaurs that lived around the same time and place include heterodontosaurs, mementosaurids, of course the ones with the long necks, and stegosaurs, although all of these are indeterminate fossil finds, so we don't have names. And other animals that lived around the same time and place include fish, salamanders, turtles, lizards, crocodiliforms, pterosaurs, and mammals.

It's a cool dinosaur. It is. I'm a little surprised I hadn't heard of it before. The Middle Jurassic really doesn't get a lot of love. No, but now that we're 500 plus dinosaurs in, I think we're going to be getting a lot more dinosaurs we hadn't necessarily heard of before. Now it's the Middle Jurassic's time to shine.

Jumping ahead in time to our fun fact is that there are probably no Paleocene dinosaurs, and the Paleocene came after the Cretaceous. Yep, right after the meteor hit that kicked off the Paleocene. Yes. By definition. So our fun fact in episode 517 was that New Zealand wasn't the only area where scientists once considered non-avian dinosaurs might have survived past the KPG.

And the gist is that some scientists have suggested dinosaurs lived in the Paleocene, the Paleocenes from 66 to 56 million years ago. And some have suggested fossils that have been found in the Hell Creek in Montana from about 64.8 million years ago show this. I didn't realize the Hell Creek made it to 64.8 million years ago.

Well, I was sort of putting together a few things there, but in episode 517, we talked about dinosaur teeth found in maybe a Paleocene deposit of the Hell Creek formation. And that's the early Paleocene from about 64.8 million years ago. Oh, I see. Okay. Yeah, because the Hell Creek for most dating ends right at the end of the Cretaceous. So you wouldn't have anything from the Paleocene in the Hell Creek normally.

Yeah, but that one, just looking at my notes, it was about 40,000 years after the asteroid hit, so that's pretty close. Yeah, that is very close. 40,000 years is nothing. Yeah, it's like a blink of an eye or a snap of your fingers. So in those cases, the argument is that these asteroids

bones, these fossils were not reworked. And reworking here means the fossils got moved, like they got washed out of the sediments and moved from their original location and then reburied in younger sediments. So that would make it look like the animal lived later than it did. And they argued in one case there was a thigh bone that was found in an area that couldn't have been washed or weathered out and then transported. Okay.

Then Spencer Lucas recently wrote Paleocene Non-Avian Dinosaurs, and how the first reports of Paleocene dinosaurs were from the 1800s, which...

I didn't realize it went that far back. And there's claims of Paleocene dinosaurs on all continents except Australia and Antarctica. Wow. However, he said that the reports had issues because either these fossils were misidentified and they weren't actually dinosaurs. They're mostly crocodilians. Well, that's been happening both ways for a long time. Yes. Or the age of the fossils or where they were found was incorrect. Yes.

or they didn't clearly establish that the dinosaur fossils were not reworked.

And he also said that you can't be completely certain if a tooth or bone is reworked because the damage or abrasion to the fossil just isn't enough for us to know. Yeah, definitely. That's what I was wondering when you said, well, that thigh bone wasn't reworked because it's a thigh bone. Well, something could rework it. You could imagine a scenario where a thigh bone erodes out of rock naturally, like happens today and rolls down a hill and then gets reburied. I think the argument there was where it...

was found, it doesn't seem likely to have been transported or something. Yeah, yeah. Definitely you could say something is more or less likely, but it's really hard to say with certainty that it definitely wasn't reworked. Yeah. Well, so Lucas was saying it means that supposed Paleocene dinosaur fossils are arguably reworked. There's no definitive evidence they are not reworked, which means that there are no for certain Paleocene dinosaur fossils.

But in the abstract, he says, quote, Nevertheless, there's no reason theoretically why there should not be Paleocene dinosaur fossils, so the search for them will continue. Hmm, hmm, hmm.

I like this version. It's almost like cryptozoology, searching for something that most people think is a fool's errand. But in this case, you could actually find something. Should get those cryptozoology people into this. Like find that Paleocene dinosaur. It's probably out there. Just keep looking. There might be a crossover. Yeah. And for sure. I mean, technically there are Paleocene dinosaurs because you've got all the birds and it's not...

completely outlandish to think that one of these many lineages of dinosaurs that we don't have today might have survived for a little bit after the asteroid. It's perfectly reasonable to think that could have happened, but we just don't have very good evidence of it yet. Yeah.

I think the best way to say that something wasn't reworked would probably be if you had a really well-articulated skeleton because you wouldn't expect something to erode out, like all the dirt of it to erode around it out and then new dirt to come in without anything really moving.

That would be really crazy. Yeah, that would be. When it's a single bone, even a big bone, even a bone that doesn't look weathered, there's always a question of if it got reworked. And when you're talking about teeth, forget about it because they're so durable. It's hard to tell if they wore down, you know, in the environment. The enamel is just so tough. Plus,

They're so little that they can just get moved around so easily. And the idea that one could get reburied quickly without getting damaged is not far-fetched at all. Yeah. Whereas if you found like a whole T-Rex articulated that's a million years past the end of the Cretaceous, that'd be pretty irrefutable evidence. Well, on that note, that wraps up this episode of I Know Dino. Thank you for listening. Stay tuned. We will have...

More dinosaur goodness for you next week. We'll have an interview with Tone Blakeslee about some exciting dinosaur footprints in Scotland. Yes. And on a personal note, I just want to say thank you to all of our listeners for helping us to create this podcast. And when I'm having a personally tough week, like the last week has been a little hard, it's just really nice to have the escape of talking on this podcast and being

diving into dinosaurs and sort of forgetting about all my troubles. So really appreciate all of you. It means a lot to us. And thank you so much for being our listeners. And to those of you who are patrons, thank you for supporting us on Patreon as well. Yes. So thanks again. And until next time.

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