Episode 381 is all about Efraasia, a Late Triassic sauropodomorph that was originally thought to be carnivorous.
We also interview Filippo Bertozzo, a postdoc researcher at the Museum of Natural History in Brussels (RBINS). He studies some of our favorite topics including: paleopathologies, air sacs, and dinosaur behavior. Follow him on Instagram in English or Italian. Or on twitch at dicendinosaur.
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In this episode, we discuss:
News:
- The latest paper on Torosaurus considers it to be a valid taxon source
- Researchers have made new recommendations to address decolonizing paleontology source
- AI will likely soon help analyze CT scans and make paleontological research more efficient source
- The game Jurassic World Evolution 2 has a new set of dinosaurs from Camp Cretaceous source
- An international group of volunteers are rushing to archive Ukrainian museum collections and other content at SUCHO.org source
The dinosaur of the day: Efraasia
- Basal sauropodomorph that lived in the Late Triassic in what is now Baden-Württemberg, Germany (Burrerschen Quarry)
- Looked like other sauropodomorphs, with a long tail, and claws
- Medium-sized and lightly built
- Estimated to be about 20 to 23 ft (6 to 7 m) long
- At first thought to be small, at around 6.6 to 9.8 ft (2 to 3 m) long, but that was based on juvenile fossils
- In 2003, Yates estimated adults were 21 ft (6.5 m) long
- Had a small, pointed, triangular skull
- Had a somewhat long neck, that was thin
- Had low neural spines on the tail
- Had gracile hands and feet
- May have been bipedal and quadrupedal
- Had long fingers and thumbs it could use to grasp food
- Wrist shape may have allowed it to walk on all fours, although not everyone agrees (some think the lower arm couldn’t pronate/rotate in a way to put the hands on the ground, which would mean it could only walk on two legs)
- Second finger was longer than the third finger
- Herbivorous
- Originally thought to be carnivorous
- Gastroliths found in association with one of the specimens, specifically 14 small smooth pebbles von Huene reported in 1932
- Type and only species is Efraasia minor
- Named after Eberhard Fraas, who found the fossils
- Fossils first found in 1902, when Albert Burrer, a stonemason, was trying to reach some hard white sandstone in a quarry near Pfaffenhofen for building (had to remove about 20 ft or 6 m of softer marl)
- Lots of fossils were in the marl and underlying soft sandstone
- When the quarry was closed from 1906 to 1914, Burrer donated the fossils to Eberhard Fraas, a professor at the State Museum of Natural History Stuttgart
- Fossils first thought to be part of three already named dinosaurs: Teratosaurus minor, Sellosaurus fraasi, Paleosaurus diagnosticus
- Fossils included vertebrae, right hindlimb, and pubic bone
- Other fossils have been found, including some in large slabs, though not fully prepared
- Fossils found include an incomplete skull, vertebrae, gastralia, ribs, humerus, pubis, femora, tibia, fibula, astragalus, end of the right pes, and more
- Friedrich von Huene first described the fossils in 1907 and 1908 as Teratosaurus minor
- At the time, Teratosaurus was thought to be a theropod (now considered to be a rauisuchian, a group of archosaurs more closely related to crocodilians than to birds and non-avian dinosaurs
- Species name refers to Teratosaurus minor being smaller than Teratosaurus suevicus (the type species)
- Von Huene also named Sellosaurus fraasi based on a partial skeleton (Sellosaurus is now a synonym of Plateosaurus); talked about in episode 152
- In 1912, Fraas reported two partial skeletons that he assigned to Thecodontosaurus diagnosticus; however, his health wasn’t great so he didn’t formally describe them and it was a nomen nudum
- Von Huene used the species name when he redescribed Fraas’ specimens in 1932, after Fraas died, and called them Paleosaurus (?) diagnosticus (meant to be a provisional name)
- In 1959, Oskar Kuhn said the name Paleosaurus was already being used, for an archosaur named in 1836, and renamed it to Palaeosauriscus
- Allen Charig first used the name Palaeosauriscus diagnosticus in 1967, although Cope had named Palaeosauriscus fraserianus in 1878 (lots of classifications, but latest seems to be it’s a phytosaur archosaur, based on a tooth)
- In 1973, Peter Galton assigned all of Fraas’ specimens to the new genus Efraasia (and named Efraasia)
- He named it Efraasia diagnostica
- In 1985, Galton and Bob Bakker suggested Efraasia be a junior synonym to Sellosaurus gracilis
- In 2003, Adam Yates analyzed fossils from the Late Triassic in what is now Germany, and found Sellosaurus fossils belonged to either Sellosaurus gracilis, which he assigned to be Plateosaurus gracilis, and the rest was Teratosaurus minor, Sellosaurus fraasi, and Palaeosaurus diagnosticus
- Efraasia was named first
- The species name was more complicated, since Von Huene had written in 1908 in the same book about Teratosaurus minor and Sellosaurus fraasi
- Teratosaurus minor appeared on the page first, so Yates chose minor to be the species name, and the full name became Efraasia minor
- Yates did not consider two other species von Huene had named based on fragmentary fossils: Teratosaurus trossingensis and Thecodontosaurus hermannianus (Galton in 1990 considered them both to be junior synonyms of Efraasia diagnostica)
- Galton said Efraasia was “an ideal ancestor for the more recent Anchisaurus”, which had some advanced features, like the first metacarpal were broader, and the first ungual was shorter
- Galton also mentioned a pathology in one of the skeletons (a nearly complete skeleton with an incomplete skull), where the right humerus was shorter compared to the left. Wrote “as the area of fracture is healed and well-finished, the animal must have lived for quite a while after the break”
- In 2017 Mario Bronzati and Oliver Rauhut described the braincase of Efraasia minor
- CT scanned the braincase
- Found that the braincase anatomy of sauropods is a result of modifications in their evolutionary history, though it’s unclear if it’s due to “rapid and drastic morphological change” or because there are a small number of braincases preserved
Fun Fact: The T. rex holotype was moved from AMNH to the Carnegie Museum when the US joined WWII to protect it from potential air raids.
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