Daemonosaurus chauliodus

NameDaemonosaurus chauliodus 

Name Meaning: Prominent toothed demon lizard 

First Described: 2011 

Described by: Sues et al 

ClassificationDinosauria, Eusaurischia, Theropoda

Daemonosaurus is a recently discovered basal theropod dinosaur from the Rhaetian age of the Late Triassic, between 208 to 201 million years ago. It was discovered in the Chinle Formation in Arizona. It lies outside of the Neotheropoda clade, making it somewhat less complex than contemporary theropods such as Coelophysis. It is known from a single incomplete skeleton. As such, it represents the group that extended from the early basal dinosaurs described previously on this blog, and later evolved into the more advanced theropods of later periods. It differs from both the early basals such as Herrerasaurus, and later early theropods such as Coelophysis. It wasn’t a very common predator, and it lived in a very diverse environment filled with the more complex early dinosaurs, many archosaurs, and other reptiles. Dinosaurs still weren’t the major life group of animals, but they were diversifying and showing more specialization from the early basal forms. It was probably a predator, but due to the hederotontion present it also could have used its teeth to shear off leaves. 





Daemonosaurus chauliodus: Primitive Dinosaurs.

Size: 1.5 m (5 feet) long.

Time Period: The Rhaetian Stage of the Late Triassic Period (First Triassic dinodissertation FTW).

Locale: The Chinle Formation of New Mexico in the United States.

Name: ‘Buck-toothed demon lizard.’ This is actually a really good name, as opposed to more pathetic named like Limusaurus.

The interrelationships of the most primitive theropods are very complicated. We have really old and basal forms like Herrerasaurus and Eoraptor (The latter of which may be a sauropodomorph), and early on in our understanding of theropods, the next stage was slightly more derived theropods like Coelophysis and Dilophosaurus. In recent years, transitions from Herrerasaurus to Coelophysis have been found in the form of primitive theropods like Tawa hallae, which exhibit features that are a mix of these kinds of dinosaurs’. While most of these basal theropods fell into the clade of Neotheropoda, Daemonosaurus is interesting in that phylogenetically, it falls outside of this very diverse clade, showing that early dinosaurs were more diverse than previously thought.

Daemonosaurus is known from the Chinle Formation of New Mexico, and was described in 2011 from bones collected in the 1980’s, illustrating just how long it takes for newly collected fossils to be described. This formation is famous for preserving many (and I mean many) specimens of the previously mentioned small theropod Coelophysis. Unlike Coelophysis and Tawa, Daemonosaurus is known from a slightly older part of the Chinle Formation. Besides its phylogenetic position, this animal is anatomically unusual.

The specific name of Daemonosaurus, chauliodus,’ means ‘buck-toothed,’ because of the strange teeth of this animal. From the tips of the upper and lower jaws extend procumbent teeth, giving it a buck-toothed appearance. Additionally, the skull of the animal was short, in comparison to primitive theropods like those mentioned before, which had long snouts in comparison. This means that it was a bit different from its slightly later relatives.

Phylogenetically, Daemonosaurus and Tawa were each other’s closest relatives, indicating that Daemonosaurus may represent a deviation from the archetypal ‘primitive theropod’ body type that is now familiar to most experts. On one hand, the animal’s species may be an anomaly and it could be the only primitive theropod that looks the way it does. On the other hand, it’s possible that Daemonosaurus was a representative of a group whose fossil relatives have not yet been excavated or described properly yet. Though it may seem unlikely that unknown groups exist, groups like the crocodilian revueltosaurs and the dinosauriform silesaurs weren’t known a few years ago, and they’re pretty major groups!

Either way, this animal was pretty interesting. Its face looks a bit like a cross between that of Bugs Bunny and a voracious demon, its body (though largely unknown) was probably typical for primitive theropods, but may have held other surprises. Its unique nature increases the known diversity of the first dinosaurs, but its fragmentary nature limits our understanding of just how diverse it was. Since it completely breaks the mold for its kind, it suggests that there are so many discoveries that are just waiting to be discovered, all of which holding the possibility of being the next revolutionary dinosaur discovery.