Paleontologists say they’ve discovered the fossilized bones of a new type of early-branching neoceratopsian dinosaur in the Japanese prefecture of Hyogo.
Life reconstruction of Sasayamagnomus saegusai. Image credit: Kanon Tanaka.
The newly-discovered dinosaur roamed our planet during the Albian age of the Early Cretaceous epoch, between 113 and 100 million years ago.
Dubbed Sasayamagnomus saegusai, the animal measured about 0.8 m (2.6 feet) in length and weighed around 10 kg.
“This new dinosaur possesses unique characteristics distinct from any known ceratopsian,” University of Hyogo paleontologist Tomonori Tanaka and colleagues said in a statement.
“Ceratopsians are a group of herbivorous dinosaurs known for their large horns and frills on their heads, the most famous being Triceratops.”
“As a primitive ceratopsian, it lacked the large horns and frills seen in later species like Triceratops.”
The skeletal bits of Sasayamagnomus saegusai were found in the Ohyamashimo Formation in southwestern Japan by the amateur geologist Kiyoshi Adachi.
“The fossil includes 17 bones, most of which belong to a single individual,” the researchers said.
“Thin sections of the tibia were examined, revealing that this individual was likely a young, not fully matured individual.”
The team’s analysis indicates that the new species forms a group with Aquilops americanus, one of the earliest neoceratopsian dinosaurs from North America, followed by the sister species Auroraceratops rugosus from China.
“Sasayamagnomus saegusai is closely related to primitive ceratopsians from North America, suggesting that ceratopsians, which originated in Asia, may have immigrated to North America around 110 million years ago during the mid-Cretaceous period,” the authors said.
“During this period, the eastern part of the Eurasian continent and North America were connected by the Bering Land Bridge, allowing animals to migrate between the two.”
“Additionally, extreme global warming resulted in vast forests in the Arctic region.”
“The convergence of these two events likely facilitated the expansion of ceratopsians from Asia to North America.”
The discovery of Sasayamagnomus saegusai is described in a paper published this week in the journal Papers in Palaeontology.
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Tomonori Tanaka et al. 2024. A new neoceratopsian (Ornithischia, Ceratopsia) from the Lower Cretaceous Ohyamashimo Formation (Albian), southwestern Japan. Papers in Palaeontology 10 (5): e1587; doi: 10.1002/spp2.1587
Source : Breaking Science News