New tiny horned dinosaur species

September 4 () –

A well-preserved fossil of a new horned dinosaur has been discovered in Japan, with unique features that distinguish it from any other ceratopsianthe triceratops family.

Ceratopsians are a group of herbivorous dinosaurs known for their large horns and head frills, the most famous being Triceratops.

As a primitive ceratopsian, the new dinosaur lacked the large horns and frills seen in later species such as Triceratops and Its tiny body length and mass are only about 80 cm and 10 kg, respectively.Furthermore, its internal bone structure and growth rings indicate that it was still a young, growing individual when it died.

This new dinosaur has been named Sasayamagnomus saegusai, whose generic name means “a small humanoid spirit that guards hidden treasures beneath the ground of Sasayama,” and the species name is in honor of the late Haruo Saegusa.

The fossil includes 17 bones, most of which belong to a single individual. Thin sections of the tibia were examined, which revealed that Sasayamagnomus was probably a young, not fully mature individual.

Sasayamagnomus is closely related to primitive North American ceratopsians, suggesting that ceratopsians, which originated in Asia, may have migrated to North America about 110 million years ago during the middle Cretaceous period.

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. In addition, extreme global warming gave rise to vast forests in the Arctic region. The convergence of these two events likely facilitated the expansion of ceratopsians from Asia to North America.

The details have been published in the magazine Papers in Palaeontology.