New Dinosaur "Yamatosaurus" from Awaji Island, Hyogo - Japan's 9th Dinosaur
2021-04-29
An ornithischian fossil discovered in 2004 in Sumoto City (Awaji Island), Hyogo Prefecture, has been identified as a new species of dinosaur.
From 23 fossil fragments including teeth, cervical vertebrae, a coracoid, and caudal vertebrae unearthed from a stratum of the Late Cretaceous (about 72 million years ago) (Kita-ama Formation), a paper was initially published identifying it as a dinosaur belonging to the Lambeosaurinae subfamily.
Fifteen years later, in 2021, a research group from Hokkaido University and Okayama University of Science conducted a phylogenetic analysis with other hadrosaurids based on 354 characteristics. They found that some parts of the shoulder bone were underdeveloped, indicating it belonged to a primitive hadrosaurid that predates the differentiation of the Lambeosaurinae subfamily.
As a new species of dinosaur, it has been named "Yamatosaurus izanagii."
It is estimated to have been 7-8 meters long and weighed 4-5 tons. It is expected to be an important specimen for exploring the origins of hadrosaurs.
Estimating the Population Density and Number of Tyrannosaurus
2021-05-21
A paper on the population density and numbers of Tyrannosaurus was published in the journal "Science" on April 16. Charles Marshall, a paleontologist at UC Berkeley, believes that "there was one Tyrannosaurus per 6-kilometer radius." This would mean 20 individuals in an area the size of Tokyo.
To estimate the population, they used a pattern called Damuth's Law, which states that "the larger the body weight of an organism, the lower its population density."
The research team's calculations also concluded that about 20,000 Tyrannosaurus existed at any one time, and a total of 2.5 billion individuals lived over a period of 2-3 million years.
Dinosaur Footprint Fossil Named After "Nobita" from Doraemon
2021-07-20
A dinosaur footprint research team from the China University of Geosciences (Beijing), in collaboration with Western paleontologists, recently announced the discovery of well-preserved dinosaur footprints in Huangjing Town, Gulin County, Sichuan Province. The footprints are a new species of the theropod ichnogenus Eubrontes and have been named Eubrontes nobitai in honor of the main character "Nobi Nobita" from the manga "Doraemon."
In July 2020, villagers in Jingyu Creek, Huangjing Town, discovered a stone slab with four footprints on its surface while cleaning the river. On August 25 of the same year, paleontologists from the China University of Geosciences and the Zigong Dinosaur Museum visited Jingyu Creek to investigate the dinosaur footprints in detail. They confirmed the presence of at least four sauropod trackways, two theropod trackways, and four isolated footprints.