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Description
Hokkaidotyrannus kobayashii
Name meaning: “Kobayashi’s Hokkaido Tyrant”
Length: 30-34 feet
Height: 10 feet at the hips
Weight: 3-4 tons
Habitat: forested coastlines
Region: japan
Era: late Cretaceous (72-70 mya)

In 2022, an old fossil hunter and his wife came across several teeth and a jaw piece of an unknown theropod several miles away from their home. The teeth were characteristic of that of a tyrannosaurid, but when they showed the fossils to some researchers at a natural history museum in Hokkaido, they speculated that the teeth and jaw piece belonged to a tarbosaurus or some other known genus. The fossils were in storage for over 10 years and wasn’t paid any attention at all until 2032. The research team was hunting for marine reptile fossils until they came across something rather odd. Among the scattered remains of ammonite and fish fossils, a dinosaur that was 40% complete was also found in the location that’s several miles away from the original specimen. This specimen included most of the skull, few neck vertebrae, shoulders, arms, spinal vertebrae, several ribs, a femur, pelvis, and the base of the tail. Everything else was possibly scavenged off by sharks and mosasaurs. After months of prepping the new dinosaur, it’s clearly a tyrannosaurid, but it’s completely different from any other tyrannosaur of the time and region. They compared the 2032 specimen (NPN-986469) with the 2022 specimen (NPN-972455) and realized that the 2 specimens belonged to the same genus. This new dinosaur was named Hokkaidotyrannus kobayashii; named after the region and original discoverer (Ginjiro Kobayashi).
In terms of evolutionary history, Hokkaidotyrannus seems to be closely related to other Asian Tyrannosaurids such as Tarbosaurus. And just like it’s tarbosaurus relative, Hokkaidotyrannus seems to primarily hunt hadrosaurs and ankylosaurs (since several unknown hadrosaur fossils have been found with bite marks and gouges that seem to come from some large theropod). Other new dinosaur discoveries have been made in japan from 2020-2040, however I won’t go in depth with them. It’s unknown if whether or not Hokkaidotyrannus hunted alone or in family groups like other tyrannosaurids, but we do know that it was considerably fast (estimated to run up to 24 mph) and it most likely hunted animals that are equal to or smaller than the Hokkaidotyrannus itself. Skin impressions have been found with the 2032 specimen, and there’s evidence of dark spots on the tail and hips. Although we don’t know the coloration of Hokkaidotyrannus, it’s possible that it’s coloration is akin to most ambush predators. Typically ranging from browns, tans, grays, black, and/or white in order to break up its silhouette.

Disclaimer 1. Feathers are for artistic and speculative purposes
Disclaimer 2. The arms are not pronated nor are they meant to be

Notable fossils
2022: a lower jaw piece with several teeth were discovered by Ginjiro Kobayashi and his wife in a rock face several miles away from their countryside home in Hokkaido. NPN-972455 is currently in display at the Hokkaido museum of natural history.
2032: NPN-986469 aka “Ryūjin” was found in a marine rock deposit by a team of researchers in Hokkaido, Japan. It was 40% complete and most likely died from a tsunami and got washed up in the ocean. Shows some evidence of being scavenged by aquatic life before being buried in sediment. It’s also on display at the same museum.

Description
Hokkaidotyrannus kobayashii
Name meaning: “Kobayashi’s Hokkaido Tyrant”
Length: 30-34 feet
Height: 10 feet at the hips
Weight: 3-4 tons
Habitat: forested coastlines
Region: japan
Era: late Cretaceous (72-70 mya)

In 2022, an old fossil hunter and his wife came across several teeth and a jaw piece of an unknown theropod several miles away from their home. The teeth were characteristic of that of a tyrannosaurid, but when they showed the fossils to some researchers at a natural history museum in Hokkaido, they speculated that the teeth and jaw piece belonged to a tarbosaurus or some other known genus. The fossils were in storage for over 10 years and wasn’t paid any attention at all until 2032. The research team was hunting for marine reptile fossils until they came across something rather odd. Among the scattered remains of ammonite and fish fossils, a dinosaur that was 40% complete was also found in the location that’s several miles away from the original specimen. This specimen included most of the skull, few neck vertebrae, shoulders, arms, spinal vertebrae, several ribs, a femur, pelvis, and the base of the tail. Everything else was possibly scavenged off by sharks and mosasaurs. After months of prepping the new dinosaur, it’s clearly a tyrannosaurid, but it’s completely different from any other tyrannosaur of the time and region. They compared the 2032 specimen (NPN-986469) with the 2022 specimen (NPN-972455) and realized that the 2 specimens belonged to the same genus. This new dinosaur was named Hokkaidotyrannus kobayashii; named after the region and original discoverer (Ginjiro Kobayashi).
In terms of evolutionary history, Hokkaidotyrannus seems to be closely related to other Asian Tyrannosaurids such as Tarbosaurus. And just like it’s tarbosaurus relative, Hokkaidotyrannus seems to primarily hunt hadrosaurs and ankylosaurs (since several unknown hadrosaur fossils have been found with bite marks and gouges that seem to come from some large theropod). Other new dinosaur discoveries have been made in japan from 2020-2040, however I won’t go in depth with them. It’s unknown if whether or not Hokkaidotyrannus hunted alone or in family groups like other tyrannosaurids, but we do know that it was considerably fast (estimated to run up to 24 mph) and it most likely hunted animals that are equal to or smaller than the Hokkaidotyrannus itself. Skin impressions have been found with the 2032 specimen, and there’s evidence of dark spots on the tail and hips. Although we don’t know the coloration of Hokkaidotyrannus, it’s possible that it’s coloration is akin to most ambush predators. Typically ranging from browns, tans, grays, black, and/or white in order to break up its silhouette.

Disclaimer 1. Feathers are for artistic and speculative purposes
Disclaimer 2. The arms are not pronated nor are they meant to be

Notable fossils
2022: a lower jaw piece with several teeth were discovered by Ginjiro Kobayashi and his wife in a rock face several miles away from their countryside home in Hokkaido. NPN-972455 is currently in display at the Hokkaido museum of natural history.
2032: NPN-986469 aka “Ryūjin” was found in a marine rock deposit by a team of researchers in Hokkaido, Japan. It was 40% complete and most likely died from a tsunami and got washed up in the ocean. Shows some evidence of being scavenged by aquatic life before being buried in sediment. It’s also on display at the same museum.