SO DINOSAURS HAVE BEEN BEFUCKENED

As we all know, there are two major groups of Dinosaurs: Ornithischians and Saurischians; with Ornithischians composed of things like Stegosaurus and Triceratops; and Saurischians consisting of things like Apatosaurus and of course, the theropods, such as Tyrannosaurus and modern birds. 

This hypothesis has been accepted for centuries and hasn’t really been challenged in the literature. 

Until today. 

In a paper that came out in Nature by Baron et al., a thorough taxonomic sampling of dinosaurs was used to examine the earliest divergence of the group - again, traditionally thought to be the split between Ornithischians and Saurischians 

They found this instead

I know that cladograms can be confusing for some of you so I made a diagram:

Basically, they found that Ornithischians are actually more closely related to Theropods than either are to Sauropodomorphs. 

Proposing the new name Ornithoscelida for this clade; and redefining Dinosauria. 

Because the definition of Dinosaurs is the most recent common ancestor Passer domesticus + Triceratops horridus (or Megalosaurus and Iguanodon, it means the same thing) and all of that ancestor’s descendants; that would thus exclude Sauropodomorphs (and imagine the headache SAND [Sauropodomorphs Are Not Dinosaurs] would cause my dudes). So Dinosaurs were redefined as Passer domesticus + Triceratops horridus + Diplodocus carnegii for everyone’s sanity. 

But is this study robust?

Well, it’s more robust than a lot of things (Ornithischians tend to be poorly sampled), but it comes to a lot of interesting conclusions, and it’s definitely not the last word on the subject. 

They did find some shared characters for their proposed Ornithoscelida that are not found in the new Saurischia, especially in the head; and the similarities between Herrerasaurids and Theropods are thought to be convergent. 

They also found Nyasasaurus, what is now thought to be a very derived almost-dinosaur or perhaps even the first true Dinosaur, to be a Sauropodomorph; which - if Nyasasaurus is as old as thought, aka, from the Middle Triassic (currently that’s being re-examined) - would push back dinosaur origins considerably. 

In addition, two of the three authors of this paper are responsible for the notorious “Dinosaurs aren’t ancestrally feathered” hypothesis - which my friend John has refuted in this link - and they use this new phylogeny to propose that filamentous integument [the fancy word for feathers] might be just ancestral to Ornithoscelida, and not found in Sauropodomorphs at all. While I will say that that hypothesis has more weight if this is the actual explanation of dinosaur origins; I feel it important to say that the criticisms John, I, and many others had with their ancestral feather paper, still stand (ie, that they don’t consider Pterosaur Pycnofibres to be homologous). 

This isn’t the last word on the subject. They don’t include the new taxa, Ixalerpeton and Buriolestes in their analysis, and as we know, Buriolestes does cause some changes to the traditional Saurischian phylogeny.  They also don’t include many other taxa that I feel would be relevant for such a study, such as Daemonosaurus, Kulindadromeus, and honestly, a more robust sampling from Ornithischia as a whole. 

The analysis is very thorough - and you can trust me to say that, because I’m not entirely the biggest fan of Barret, due to the whole feathered dinosaur argument - but obviously it requires more research, more examining, and replication from other scientists. It does make one thing clear though: the origin of dinosaurs is not set in stone, and we have a lot of work to do to understand it better. 

Avatar

Bathornis grallator, a flightless bird about 75cm tall (2′6″) from the Late Eocene and Early Oligocene of Midwestern USA (~37-34 mya).

It was originally mistaken for a long-legged vulture (under the name Neocathartes) when first discovered in the 1940s, but later studies have shown it was actually one of the smaller members of the bathornithids – close cousins of the more well-known South American “terror birds”, successfully occupying terrestrial predator niches alongside large carnivorous mammals.

Tongtianlong limosus

By Jack Wood on @thewoodparable

Name: Tongtianlong limosus

Name Meaning: Tongtianyan Dragon

First Described: 2016

Described By: Lü et al. 

Classification: Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Oviraptorosauria, Caenagnathoidea, Oviraptoridae

Tongtianlong is an Oviraptorid (so a Chickenparrot) from the Nanxiong Formation in Jiangxi Province, China, dating back to the Maastrichtian age of the Late Cretaceous, approximately some time between 72 and 66 million years ago. Unlike other Chickenparrots, it had a dome shaped crest and a very rounded beak, giving its head a very pug-like appearance compared to other Chickenparrots. It was very well preserved, but portions were damaged during the excavation; it was also preserved in a unique pose, its head raised and arms splayed. It may have been trapped in mud, and died during its attempt to break free. It lived alongside a great number of Chickenparrots, such as Banji, Ganzhoussaurus, Jiangxisaurus, Nankangia, and Huanansaurus, as well as other dinosaurs such as Microhadrosaurus, Gannansaurus, Qianzhousaurus, and Nanshiungosaurus

Sources:

Lü, J., R. Chen, S. L. Brusatte, Y. Zhu, C. Shen. 2016. A Late Cretaceous diversification of Asian oviraptorid dinosaurs: evidence from a new species preserved in an unusual posture. Scientific Reports 6: 35780. 

Shout out goes to @tuakpidiwalk!

i gave this character a name but i forgot it and i keep just calling him softboy… hes a troodon! i tried to make body and feathering all sciencey and stuff but his markings are just for fun, they are the same as the anthro version of his character

if u have any tips for paleoart please let me know! i wanna actually get into it as a serious hobby cause i love speculative biology and dinosaurs and all that shit

if you want art like this, check out my commissions! gift art for others is 10% off for the holidays!

Avatar

Troodon teeth are very abundant in Alaska, but they are about twice as big as what’s expected for the species in more southern areas. It also seemed to be a more significant member of the ecosystem, as opposed to being much rarer elsewhere. What was happening with the Troodons in Alaska?

Read more at Earth Archives.

You can buy prints and merchandise of this and other illustrations at 252mya.com, go check it out!

Avatar

In 2015, Lida Xing was visiting a market in northern Myanmar when a salesman brought out a piece of amber about the size of a pink rubber eraser. Inside, he could see a couple of ancient ants and a fuzzy brown tuft that the salesman said was a plant.

As soon as Xing saw it, he knew it wasn’t a plant. It was the delicate, feathered tail of a tiny dinosaur.

“I have studied paleontology for more than 10 years and have been interested in dinosaurs for more than 30 years. But I never expected we could find a dinosaur in amber. This may be the coolest find in my life,” says Xing, a paleontologist at China University of Geosciences in Beijing. “The feathers on the tail are so dense and regular, this is really wonderful.”

He persuaded the Dexu Institute of Palaeontology to buy the artifact.

After analyzing the delicate tail, Xing and his colleagues in China, the U.K. and Canada now have an idea of what type of dinosaur it is, and of the evolutionary clues it holds. Their research was published Thursday in the journal Current Biology.

They say that 99 million years ago, a baby dinosaur about the size of a sparrow got stuck in tree sap and never made it out. Had the young dinosaur had a more auspicious day, it would have grown up to be a little smaller than an ostrich.

Photo: Ryan McKellar/Royal Saskatchewan Museum Caption: A baby dinosaur’s tail is encased in amber along with ants, a beetle and plant fragments.

Source: NPR
Avatar

Is it a six-foot turkey? No, it’s Dakotaraptor!

Living at the very end of the Cretaceous (~66 mya) in South Dakota, USA, this was one of the largest “raptors”, estimated to have measured about 5-6m long (16′4″ - 19′8″). Although it was closely related to other famous giant dromaeosaurs like Utahraptor, its large size seems to be the result of convergent evolution.

Quill knobs on its arm bones confirm the presence of large pennaceous wing feathers in giant raptors, although it was much too large to be capable of flight. Two different size morphs were also found amongst the fossil remains of several individuals – larger heavily-built “robust” forms and smaller lightly-built “gracile” ones – all of which appear to have been fully mature adults. This may represent sexual dimorphism, although it’s unclear which morph might have been which.