Episode 239 is all about Riojasaurus, a Triassic sauropodomorph from Argentina that may have been bipedal.
We also interview Tadd Galusha, writer and illustrator of the graphic novel Cretaceous. He’s a comic artist and illustrator, who also created the web comic The Backwoods and worked on Godzilla and TMNT/Ghostbusters 2. You can follow him on Instagram or Twitter, @TaddGalusha, and get his book on Amazon.
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In this episode, we discuss:
News:
- The hadrosaur Prosaurolophus may have grown a large squishy nose as it aged to attract mates source
- In Chongqing, China, scientists have found a new yet to be named dinosaur species source
- In Jiangsu Province, China, four dinosaur footprints have been found which had been previously attributed to legendary Chinese humans source
- In Nevada, the Las Vegas Natural History Museum has a new exhibit, “Dinosaurs Take Flight” that focuses on Archaeopteryx source
- The Jurassic World Evolution Claire Dearing DLC was released, we livestreamed it in Part 1, Part 2, and Part 3 on Youtube
The dinosaur of the day: Riojasaurus
- Sauropodomorph that lived in the Late Triassic in what is now the La Rioja Province in Argentina (Los Colorados Formation)
- Genus name means “Rioja lizard”
- Type species is Riojasaurus incertus
- Incertus means uncertain in Latin
- Many individuals have been found, maybe up to 20
- Grew to be about 33 ft (10 m) long
- Had a long neck and tail
- Had bulky legs, that were dense and very large for an early sauropodomorph
- Had hollow cavities in its vertebrae
- Had four sacral vertebrae, instead of three, like other early sauropodomorphs
- Probably was slow, and scientists used to think it walked on four legs, but could rear up on its hind legs
- Forelimbs and hindlimbs are similar in length
- But in 2016 Scott Hartman found Riojasaurus was probably bipedal, because the hands were relatively straight back and the shoulder girdle was mostly immobile
- May have been cathemeral, based on the scleral rings found in Riojasaurus (compared to modern birds and reptiles)
- Thought to be related to Melanorosaurus, a basal sauropodomorph that lived around the Late Triassic, but studies at Bristol University in England found some key differences, such as longer bones in the neck
- Both were large for their time
- Named in 1967 by José F. Bonaparte
- No skull was found with the holotype, but José F. Bonaparte and José A. Pumares described a nearly complete skull in 1998
- Skull was found on an exploratory trip in 1986
- From the back, the skull looks pretty narrow
- Bonaparte and Pumares found the skull had conical teeth, and they also said the tooth row in the lower jaw is on the internal side of the jaw, “and its external border, or cheek, extends to the anterior portion of the dentary, which suggests the presences of thick lips”
- They also found some shared derived characters between Riojasaurus and Coelophysis, which may mean they had a close common ancestor (similar height and elongation of the skull, for example)
- Only known riojasaurid from South America
- Other sauropodomorphs have been found in the Los Colorados Formation, including Coloradisaurus and Lessemsaurus
Fun Fact: Richard Owen named Dinosauria in 1842, and one year later he unknowingly reused the deinos root to name a dinosaur—the Moa Dinornis.
