Episode 362 is all about Amurosaurus, a lambeosaurine hadrosaur that lived in the Late Cretaceous in what is now Russia.
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In this episode, we discuss:
News:
- The new ceratopsian, Sierraceratops turneri, was named from New Mexico (after previously being called Torosaurus) source
- Over 100 eggs and 80 skeletons of Mussaurus show that they may have lived in age segregated groups source
- A new dinosaur was found in Inner Mongolia source
- “Big John” the Triceratops was auctioned for $7.74 million, about five times the estimated value. source
- A newly restored Plateosaurus is on display at the Natural History Museum in Vienna source
- The Moab Museum in Utah has a new Apatosaurus femur on display source
- The Science Museum of Minnesota has a new exhibit, Ultimate Dinosaurs source
- The Journey Museum and Learning Center in South Dakota has a new replica of Tinker the T. rex on display source
- Three dinosaur statues were stolen from Dinosaur Park and found damaged at a frat party at the University of Texas Austin source
- Jack Horner and paleoartist Fabio Pastori are selling a set of 100 NFTs to raise money for paleontological research source
The dinosaur of the day: Amurosaurus
- Lambeosaurine hadrosaur that lived in the Late Cretaceous in what is now Russia (Udurchukan Formation)
- Looked similar to Corythosaurus, bulky build, duckbill, strong legs
- Mostly walked on two legs (facultative biped)
- Estimated to be 20 ft (6 m) long
- Gregory Paul estimated 26 ft (8 m) long and weighed 6,600 lb (3,000 kg)
- Probably had a hollow crest on its head (but crest has not been found)
- Herbivorous
- Had a dental battery
- Maxillary teeth were “narrow, diamond-shaped, perfectly straight, and symmetrical”
- Had a massive coracoid (part of the shoulder)
- Had a robust ulna (part of the forearm)
- Had a gracile radius (other part of the forearm)
- Had a robust femur
- Had elongated pencil-shaped metacarpals (in the hands) and robust metatarsals (in the feet)
- Type and only species is Amurosaurus riabinini
- Described in 1991 by Yuri Bolotsky and Sergei Kurzanov
- Genus name means “Amur lizard”
- Genus name comes from the Amur River, near where Amurosaurus was found (called Heilongjiang or “Black Dragon River” in Mandarin), is the border of Russia and China
- Species name in honor of paleontologist Anatoly Riabinin
- Fossils all found in one bonebed that was discovered in 1984
- Brief history of the area:
- In 1902 Colonel Manakin collected the first dinosaur bones (isolated bones) from Cossack fisherman near the Amur River on the Chinese side of the river
- In the summers of 1916 and 1917 the Geological Committee of Russia excavated the area. In 1925 and 1930 Riabinin said the hadrosaur bones were abundant in the area, and he named two: Trachodon amurense and Saurolophus krystofovici (now both considered to be nomina dubia–too fragmentary and no unique features)
- In 1957 Rozhdestvensky first mentioned dinosaur fossils from the Russian part of the Amur region
- In 1984 Yuri Bolotsky and the Amur Complex Integrated Research Institute of the Far Eastern Branch of the Russian Academy of Sciences found a large bonebed in the area
- Only 200 square meters were excavated as of 1991, and several hundred bones were found, mostly from lambeosaurines (90% belonged to Amurosaurus, mostly juveniles)
- The rest are hadrosaurines like Kerberosaurus. Also found turtle fragments and theropod teeth and many toothmarks on the bones (predators or scavengers)
- In 1991 Bolotsky and Kurzanov described some of the lambeosaurine fossils as Amurosaurus riabinini
- More than 90% of the bones found are from lambeosaurines, but the “skeletons are complete disarticulated and mixed”
- Based on the skeletons being mixed up and the way the long bones were oriented, the bones were probably deposited in a river or floodplain kind of environment. But because the bones are so well preserved, including fragile skull pieces, they probably weren’t transported over a long distance
- The random way the bones were oriented may mean they were suddenly stopped in being transported before fossilizing
- Only the holotype skull pieces and some vertebrae are known to be from the same individual
- Holotype is a left maxilla (upper jaw bone) and dentary (lower jaw bone)
- Holotype skull has sutures
- But, so many bones found in the bonebeds, can construct most of the skull and skeleton
- Many unique features in the skull, and the shape of the lower arm bone (ulna)
- Had bones on the roof of the skull that seemed to support a crest
- In 2004, Pascal Godefroit and others re-described Amurosaurus
- Said that based on lambeosaurini (Lambeosaurus, Corythosaurus, Nipponosaurus, etc.) and parasaurolophini (Parasaurolophus, Charonosaurus) dinosaurs being found in North America and Asia, seems there was a lot of migration between Asia and North America, but it’s not always clear which way they went (east to west or west to east)
- But, all known basal lambeosaurines are from Asia, so seems lambeosaurines originated in Asia
- In 2011, Pascal Godefroit and others wrote about recent advances on the study of hadrosaurid dinosaurs in Heilongjiang
- Found that less than 2% of the bones excavated from the Amurosaurus bonebed had potential tooth marks, so scavenging was either limited or there was so much food for scavengers they didn’t have to scrape at the bones
- Based on the size and frequency of femurs, tibiae, humeri, and dentaries, there are mostly late juveniles and subadult Amurosaurus. Possible that younger Amurosaurus lived separated from adults and rejoined the herd when they were more grown
- Most individuals are small to medium-sized, but some isolated bones suggest Amurosaurus could get large, maybe even larger than Shantungosaurus giganteus (up to 48 ft or 14.7 m long)
- Amurosaurus lived in “savannah-like valleys with oasis vegetation along the banks of lakes and river” in a warm and relatively arid climate
- Can see an AR view of Amurosaurus with Google’s Arts and Culture’s Meet an Ancient Animal feature
Fun Fact: Sierraceratops is at least the 14th named Chasmosaurine from the last 9 million years of the Mesozoic.
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