HERE'S A FUN DINOSAUR FACT

So, uh, here's the thing. This was supposed to be some short blog on quick and fresh dino facts, right? I mean, nothing spices up small talk better than a dinosaur fun fact. However, I’m a dumbass, and I ended up doing a whole entire research piece in all of this 'cause, you know, I fucking love this stuff. And it felt really sad to simply cut all this stuff off just to fit it all. Anyway, now I have seven .txt files in my computer that go into great length about dinosaurs, and I'll be gradually posting them. Don't expect any consistency in these uploads since I'm still in college and I have a shit ton of things to do. BUT this is what I love most, and I love working on it. So, get a bag of chips or something and get ready to learn!!!!!!!

Image credits to Marcos Villaroel in Artstation.

So, WHAT THE FUCK IS A CHILESAURUS? Short answer: nobody knows for sure. Long answer;

First, we need to cover some basic ground here. Dinosaurs, being the cool animals they are, get to have phylogenetic classifications. This is basically a system made up to establish genetic relationships between different animals. And usually, when you explore the phylogenetic tree of a specific kind of dinosaur, you can see how they started off as a weird looking thing into the T-rex we all know and love. This is also where you could picture the famous (although fundamentally wrong) image of a monkey "evolving" into a human. This image describes the phylogenetic relationships established in the human "branch" of a hypothetical genetic tree. Did any of that make sense? No? No worries, the main idea is that this is a system that's very important when talking about dinosaurs. Because the whole point of looking for new fossils and analyzing them is to get a general idea of their evolution. And one of the most important jobs for a paleontologist is to correctly classify a new species into its rightful phylogenetic tree.

Coming back to our main subject; As the name suggests, Chilesaurus was found in, you guessed it, Chile. It lived during the Jurassic period around 150-146 million years ago. The rate of its findings suggest that it was a rather common species at the time, but what really stands out is that it seems to be a mix of very different dinosaurs. To be clear, the relationship between a Triceratops, a Brachiosaurus and a Giganotosaurus is very distant indeed. All these dinosaurs represent very different "types" of creatures, ornithischians, sauropods (and sauropodomorphs), and theropods respectively. So you can imagine the surprise, when piecing this lil guy together, when they find a mix of all these lineages in one creature. Like a paleontological Frankenstein--and honestly, anyone’s natural would be: “what am I even looking at?”. Its not surprising to know that its phylogenetic classification has been subject of controversy since its discovery.

Image credits to Carlost1205 on Deviantart.

It seems to have a mix of three specific "types", as it shares features from theropods, ornithischians and sauropodomorphs. All that in a single package. There are various theories as to why this is is. Originally, Chilesaurus was described and categorized as a _theropod_, theorized to be close to the origins of tetanurae (which includes famous dinosaurs like Dilophosaurus and Cryolophosaurus). Its position on the tree, specifically, was close to Therizinosaurians (you may recall the not-so-recent appearance of Therizinosaurus in Jurassic World Dominion. This family includes it and everything else that looks like it). However, this placement was a difficult bet, due to particular anatomical features that didn't quite fit with what was known at the time.

SO controversial. Anyone loves drama, scientists love puzzles, and Chilesaurus had both. A wide variety of studies followed, taking advantage of the large amount of material available. In the midst of all this, there is one particular article that stands out. This paper proposed a middle ground in this debate. The authors postulated that Chilesaurus was a transitional form between theropod and ornithsichian. Basically positioning it as a surviving member of ornithischia that derived into theropoda, and eventually diversified until the cretaceous. Sounds good, yeah. No problem there.

UNTIL. The authors Muller et. al. commented on the mentioned above study, with;

[...] However, we observed that the results presented by Baron and Barrett could not be replicated using the same dataset and parameters provided by the authors. Indeed, following that dataset (..) and parameters, C. diegosuarezi nests within Sauropodomorpha..."

Basically anouncing that after replicating the experiment, they didn’t get the same result. A serious accusation... so they made a RESPONSE.

They published another article, refutating their claim. Turns out it was all a simple misunderstanding, since the authors claim to have accidentally published the paper with the wrong dataset. They contacted the editors, replaced it with the new, and even the commenters were able to replicate the original results.

Yeah. Kind of anticlimactic if you ask me. But notice that this old dataset suggests that this was not a first-time guess. A lot of phylogenetic trees had to be generated, the dataset had to be re-assembled many times. This only goes to show how difficult it was to even formulate an _educated_ guess for the thing.

Chilesaurus is still in debate, and the less we know about it, the more important it is. If we can’t figure it out with the knowledge we have, then clearly something’s missing — and progress happens when we find that missing piece. I mean, it does sound nice to find a dinosaur and be able to comfortably categorize it on the first go. But the true fun of science is to rewrite everything, to find something new! It keeps the work fresh, y'know?

Anyway, yeah, that's the story for the day. Now that you know of this dinosaur, you can give a creative answer when someone asks "what's your favorite dinosaur?"

I don’t know if its MY favorite... but it certainly made it to the top 10.

References go here but im too lazy to copy paste it.