Episode 296 is all about Daemonosaurus, the small, buck toothed, Triassic carnivore from New Mexico.
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In this episode, we discuss:
News:
- Oculudentavis is now officially just HPG-15-3 after the Nature article describing it was retracted source
- A thorough reanalysis of Dilophosaurus specimens clarified its features and relationship to other dinosaurs source
- A pair of Bissektipelta braincases shows details of how its blood vessels worked source
- According to NPR, one-third of the museums in the U.S. may permanently close this year source
- The Quarry Exhibit Hall at Dinosaur National Monument has reopened with timed tickets source
- Dinosaur Adventure Drive-Thru is in St. Paul, Minnesota through August 9th source
- Bryce Dallas Howard shared some photos on Twitter of the bruises she’s gotten doing stunt work for Jurassic World Dominion source
- In August, the Jurassic Park Trilogy is coming back to Netflix in the US source
- The trailer for Jurassic World: Camp Cretaceous was released source
The dinosaur of the day: Daemonosaurus
- Basal theropod that lived in the Late Triassic in what is now New Mexico, US (Chinle Formation at Ghost Ranch)
- Some estimates to be about 5 ft (1.5 m) long, others estimate 7 ft (2.2 m) long and weighed 49 lb (22 kg)
- Probably about the same height as a tall dog
- Skull was about 5.5 in (14 cm) long
- Had very large eye sockets
- Had a short skull and long teeth, which was different from other early theropods that had long heads and jaws
- Carnivorous, had serrated teeth
- Had large premaxillary and maxillary teeth in the upper jaw (large front teeth)
- The first two teeth in the lower jaw are large
- Had heterodont teeth (different shaped teeth)
- Premaxilla (tip of the upper jaw) and the front upper (anterior maxillary) jaw teeth are very large compared to the back upper (posterior maxillary) teeth
- Hans Dieter-Sues said the large front teeth were good for seizing and killing prey, and it probably had a powerful bite becuase of the short, deep snout (according to LiveScience)
- Only the holotype has been found
- Holotype includes a nearly complete skull, vertebrae, and ribs
- Skull was nearly complete but crushed
- Type species is Daemonosaurus chauliodis
- Genus name means “demon lizard”, and refers to the legends about evil spirits at Ghost Ranch
- Species name means “buck toothed” or “prominent toothed” or “outstanding teeth”
- Fossils were found by E.H. Colbert in the 1980s
- Found in a block of mudstone
- The mudstone was on loan from Carnegie Museum to the State Museum of Pennsylvania, and visitors could watch volunteers prepare the rock. A volunteer found the Daemonosaurus skull
- Named in 2011 by Hans-Dieter Sues and others
- Unclear if the holotype is an adult or juvenile (large eye sockets and no fused bones between braincase bones point to juvenile, but sutures on vertebrae near the skull are closed like an adult’s)
- Found with fossils of Coelophysis
- Colbert said in 1989 that Daemonosaurus and a few Coelophysis were washed into a small pond, then they drowned and were buried quickly after
- Lived in a warm, monsoon-like climate with lots of rain
- Lots of prey around, and animals in general (Coelophysis, reptiles, fish)
- Vegetation included conifers, ferns, horsetails
- Lots of animals found close together, probably because of a flash flood
- Before Daemonosaurus was found, there was a gap in the Mid Triassic and paleontologists thought these early carnivores had gone extinct (now know they were diverse and lived in the Late Triassic)
- Helps show the diversity of early theropods
- Helps show that theropods had different skull shapes
- Different skull shapes meant different feeding strategies, so they could co-exist
- Daemonosaurus helps show the link between basal and later theropods
- Based on its features, looks like a mix of early theropods like Eodromaeus (from South America) and more advanced theropods like Tawa (also from Ghost Ranch), but it lived after both Eodromaeus and Tawa, so it’s very strange and probably means Daemonosaurus came from early theropods that came to North America and lived alongside newer evolving theropods. One of the features is cavities on some of the neck vertebrae related to the structure of the respiratory system, according to Hans-Dieter Sues, which is the type of respiratory system we see in neotheropods and modern birds
- Hans-Dieter Sues said Daemonosaurus may be part of a dinosaur lineage that didn’t evolve later in the Mesozoic
- Daemonosaurus fossils are now in the collection of the Carnegie Museum of Natural History
Fun Fact: There are many animals (and likely dinosaurs) that benefit from forest fires.