Daemonosaurus chauliodus
- 演化之聲
- 4 days ago
- 2 min read
Age
Triassic（Rhaetian）
203 Ma
Taxonomy
Kingdom：Animalia
Phylum：Chordata
Class：Reptilia
Order：Saurischia
Genus：Daemonosaurus
Species：Daemonosaurus chauliodus
Morphological description
Daemonosaurus chauliodus was a small dinosaur, estimated to have reached only about 1.5 meters in length.
Its skull was lightly built, relatively narrow and tall. The orbits were proportionally large and nearly circular, differing markedly from the more typical oval-shaped orbits of Neotheropoda. A distinct ridge was present along the lateral surface of the jugal. The snout was comparatively short, and the teeth at the front of both the premaxilla and maxilla were enlarged. The anterior teeth of both the upper and lower jaws projected forward and outward, while the posterior teeth were noticeably smaller. On the third cervical vertebra, an oval-shaped deep pneumatic recess occupied approximately 40–50% of the centrum length at the junction between the vertebral centrum and neural arch.
Etymology
The generic name Daemonosaurus is derived from the Greek words daimon (“evil spirit” or “demon”) and sauros (“lizard”), referring to the local ghost legends associated with Ghost Ranch, where the fossil was discovered.
The specific name chauliodus comes from Greek and refers to its conspicuously prominent teeth.
Biological interpretation
The fossil of Daemonosaurus was discovered during the 1980s by an excavation team from the Pennsylvania State Museum at Ghost Ranch in New Mexico, USA. The specimen, catalogued as CM 76821, was found in a rock block containing fossils of Coelophysis bauri. The specimen consists of a nearly complete but heavily distorted and fragmented skull, the anterior cervical vertebrae, and a small number of ribs.
Phylogenetic analyses indicate that Daemonosaurus was a non-neotheropod theropod dinosaur, representing part of an early radiation of dinosaurs. It appears to have been closely related to Tawa, which was also discovered at Ghost Ranch but lived slightly earlier. Earlier studies noted a significant morphological gap between Herrerasaurus and Eoraptor on one side and neotheropod dinosaurs on the other. The discoveries of Daemonosaurus and Tawa helped bridge part of this gap and provided additional support for the hypothesis that Herrerasaurus and Eoraptor belong within Theropoda rather than representing basal saurischians.
Approximately 200 million years ago, Ghost Ranch was situated near the equator and experienced a warm climate with abundant seasonal rainfall. These conditions supported a diverse ecosystem but also resulted in frequent flooding events. Researchers have suggested that Daemonosaurus and Coelophysis were likely swept into a pond by floodwaters, where they were subsequently buried and fossilized.
（Author: Bai Leng）
Reference
1. Hans-Dieter, S., Sterling J. N., Berman, D. S., Henrici, A. C. (2011). A late-surviving basal theropod dinosaur from the latest Triassic of North America. Proceedings of the Royal Society B.
2. Choi, C.Q. (2011). T. Rex had a toothy ancestor that couldn't cut it. Live Science.
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