Episode 292 is all about Enigmosaurus, the aptly named Therizinosaur enigma.
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In this episode, we discuss:
News:
- New finds show Protoceratops & Mussaurus had soft-shelled eggs source
- Two new dinosaurs, Navajoceratops & Terminocavus, were named from New Mexico source
- Crystal Palace Dinosaurs is looking for new security to keep their sculptures safe source
- The Carnegie Museum of Natural History has a new Dinosaur Armor exhibit source
- A Make-A-Wish child in South Florida was surprised with a dinosaur-themed car parade source
The dinosaur of the day: Enigmosaurus
- Therizinosaur theropod that lived in the Late Cretaceous in what is now Mongolia (Bayan Shireh Formation)
- Estimated to be 16.4 ft (5 m) long and weigh between 1,000 to 2,000 lb (454 to 907 kg), about the same weight as a horse
- Bipedal, herbivorous, maybe omnivorous
- Type and only species is Enigmosaurus mongoliensis
- Genus name means “Enigma lizard” or “Enigmatic lizard”
- From the Greek word that means mysterious
- Found a well preserved pelvis and other remains (including a large left femur, which is too large to be clearly associated with the pelvis)
- Named because of the unusual shape of its pelvis
- Pelvis is large and the pubis bones point backward, which is why it’s enigmatic
- First reported in 1979, when its pelvis was compared to other theropods, but not much known about therizinosaurs yet
- Nicknamed the “Dinosaur from Khara Khutul” (the locality in the Bayan Shireh Formation where it was found), and considered part of Segnosauria when briefly described by Rinchen Barsbold and Altangerel Perle in 1980
- Officially named and described in 1983 by Barsbold
- Based on a partial skeleton, no skull, with a well preserved pelvic girdle
- Species name refers to Mongolia
- May have been an older adult specimen found, based on the pelvis having areas of bone resorption and bone remodeling of the ilium, the uppermost, largest part of the hip bone. Could be a unique characteristic of Enigmosaurus, but would need more analysis
- Possibly synonymous with Erlikosaurus, a medium-sized herbivorous dinosaur with a small skull and beak, and was also one of the dinosaurs in Jurassic World: Fallen Kingdom
- Both were found in the same formation, but the pelvis of Erlikosaurus is unknown, so hard to compare and determine if Enigmosaurus is a junior synonym of Erlikosaurus
- On the other hand, the Enigmosaurus pelvis doesn’t look like the pelvis of Segnosaurus, another therizinosaur from the same formation. Also Erlikosaurus and Enigmosaurus were found in different strata, so most scientists considered them to be separate taxon
- Third therizinosaur found in the Bayan Shireh Formation
- Other dinosaurs that lived in the same time and place included therizinosaurs Erlikosaurus and Segnosaurus, an unnamed velociraptorine
- Also lots of fossil fruits found, so many angiosperm plants around
- First Cretaceous therizinosaur found in Mongolia was Therizinosaurus cheloniformis, named in 1954 by Maleev and found in the Nemegt Formation
- May have had good hearing and sense of smell, based on a CT scan of Erlikosaurus and partial braincases of two other therizinosaurs, in a 2019 study by Stephan Lautenschlager and others
- Would be helpful for foraging, avoiding predators, and acting socially
Fun Fact: There are at least 6 dinosaur genera named in honor of Canada or locations within its borders.
