Episode 415: A huge ornithomimosaur in Mississippi. Plus Ornithoscelida is dead; Stegoceras head-butting; Dinosaur bite forces; Sculpting an Amargasaurus head; and much more
News:
- A new very large ornithomimosaur was discovered in Mississippi source
- Ornithoscelida is dead, but the dinosaur family tree might be getting another update source
- Scientists found that the early dinosaur Coelophysis had a lot of variation in how they grew source
- The pachycephalosaurid Stegoceras may have head-butted source
- There’s a new predictive modelling framework to estimate dinosaur bite force source
- Scientists reconstructed an Amargasaurus head source
- Phys.org featured Doug Boyer, founder of MorphoSource, a digital repository of museum specimen 3D scans source
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The dinosaur of the day: Udanoceratops
- Leptoceratopsid dinosaur that lived in the Late Cretaceous in what is now Mongolia (Djadokhta Formation)
- Estimated to be about 13 ft (4 m) long and weigh 1500 lb (700 kg)
- Largest known leptoceratopsid, so far
- Walked on four legs
- Paleoart shows a short tail
- Skull was about 24 in (60 cm) long
- Had a short, deep skull
- Had a short frill, and no horns on the nose or over the eyes
- Had robust, deep jaws, and a curved lower jaw
- Had a parrot-like, toothless beak
- Herbivorous
- Probably grasped or cropped vegetation with its beak and sheared and crushed with its teeth
- Probably ate tough vegetation
- Holotype found in the 1980s
- Described in 1992 by Sergei Kurzanov
- Type species is Udanoceratops tschizhovi
- Genus name means “Udan’s horned face”
- Genus name refers to where the fossils were found (Udan Sayr locality of the Djadokhta Formation)
- Holotype is a large individual and includes a well-preserved, nearly complete skull, and vertebrae
- In 1993 a skull was assigned to Udanoceratops
- Skull was nearly 3 ft or 1 m long and came from the nearby Bayan Mandahu Formation, according to Tomasz Jerzykiewicz
- In 2020, Lukasz Czepinski said the skull most likely belonged to Protoceratops hellenikorhinus
- Viktor Tereshchenko referred a juvenile specimen to Udanoceratops in 2004
- Specimen came from the Baga Tariach locality, which Tereshchenko said was part of the Djadokhta Formation
- In 2010, Mahito Watabe and others found that the Baga Tariach locality correlated the best with the Barun Goyot Formation
- The specimen has been assigned “Udanoceratops” sp., and ?Udanoceratops sp (means there’s some uncertainty)
- In 2006, V. S. Tereshchenko suggested Udanoceratops was “facultatively aquatic” and that on land Udanoceratops could move both quickly and slowly (“rapid and slow locomotor modes”)
- Said there was “interesting data” from previous papers that support the idea of protoceratopoids being buried in ways that suggest they had an “affinity to water bodies during the animal’s life (amphibiotic mode of life)” (meaning having an amphibious life)
- Basically, no “traces of long transportation before burial” which means they were buried close to where they died
- Looked at a number of protoceratopoids, including Udanoceratops, and studied features “that are presumably connected with particular adaptations, mode of life, and locomotion”
- Said Udanoceratops had 10 thoracic vertebrae (upper and middle of the back), a somewhat flexible neck
- Found that the upper and middle back area “is relatively weakly mobile” while the lower back “shows a high mobility”
- Said protoceratopsids were “probably amphibionts and relatively good swimmers” based on the flattened tail with high neural spines (good for swimming movements). Also the presence of mollusks in some nests, and the distribution of nests support the water idea
- Said based on the tail, “Bagaceratops was probably most aquatic, followed by Protoceratops, Udanoceratops, and the most terrestrial Leptoceratops”
- Not sure how widely accepted the aquatic ideas are
- Other animals that lived around the same time and place include Avimimus (oviraptorosaur), Bagaceratops (ceratopsian), Protoceratops (ceratopsian), amphibians, crocodylomorphs, mammals, turtles
Fun Fact:
Scientists found that there may have been a common origin 407 million years ago for nose-breathing vertebrates to communicate with sound.
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