Pronunciation: nip-ON-o-SOR-us
Meaning: Japan lizard
Author/s: Nagao (1936)
Synonyms: None known
First Discovery: Saghalien, Russia
Discovery Chart Position: #173
Nipponosaurus sachalinensis
You're wondering why a dinosaur discovered in Russia was named Nipponosaurus—meaning "Japan lizard"—right? Well, it was found on Sakhalin Island in the North Pacific, which was the subject of much squabbling and military shenanigans between Russia and Japan during the 19th and 20th centuries, with ownership of the island, in full and in portions, passing back and forth. But in 1936, when Nipponosaurus was named and described by Professor Takumi Nagao of the Imperial University of Hokkaido, it belonged to Japan and was known as Karafuto. When Russia seized complete control during the dying days of World War II in 1945 and ousted the last of the "Nippons" (Japanese folks) in 1949, Nipponosaurus had to stay. And the name had to stay too. You can't rename dinosaurs willy-nilly just because you stuck your flag in a lump of land. It's a national treasure, FGS. And it doesn't matter which nation holds jurisdiction.
As the dust settled, Nipponosaurus was all but forgotten for 64 years. But with rumours of its dubious nature beginning to gather steam, Hokkaido University graduate student Daisuke Suzuki set about proving its validity in 2004. Recovering Nipponosaurus as a lambeosaurine hadrosaurid and a close relative of North America's Hypacrosaurus altispinus were the fruits of his research. However, he also proved it was a juvenile specimen, with so much growing and changing still to do. And that only stoked the fires of doubt in the minds of certain palaeontologists, who were convinced that an immature individual had no right to be the exemplar of an entire genus.
In 2017, Ryuji Takasaki—another Hokkaido University graduate—revisited Nipponosaurus and dissected a femur, rib and chevron to inspect the LAGs (lines of arrested growth, much like the growth rings of trees) to determine its age and compared it to other "duck-billed" dinosaurs that are known from multi-age specimens to observe how their bones changed as they matured. Once again, Nipponosaurus was confirmed as immature. But this latest study also proved that certain features of the hadrosaurid jaw and proportions of the lower arm do not change with age, so Nipponosaurus is perfectly valid after all, and it sports features not seen in other members of its family, meaning it's a worthy name-bearer.
As the dust settled, Nipponosaurus was all but forgotten for 64 years. But with rumours of its dubious nature beginning to gather steam, Hokkaido University graduate student Daisuke Suzuki set about proving its validity in 2004. Recovering Nipponosaurus as a lambeosaurine hadrosaurid and a close relative of North America's Hypacrosaurus altispinus were the fruits of his research. However, he also proved it was a juvenile specimen, with so much growing and changing still to do. And that only stoked the fires of doubt in the minds of certain palaeontologists, who were convinced that an immature individual had no right to be the exemplar of an entire genus.
In 2017, Ryuji Takasaki—another Hokkaido University graduate—revisited Nipponosaurus and dissected a femur, rib and chevron to inspect the LAGs (lines of arrested growth, much like the growth rings of trees) to determine its age and compared it to other "duck-billed" dinosaurs that are known from multi-age specimens to observe how their bones changed as they matured. Once again, Nipponosaurus was confirmed as immature. But this latest study also proved that certain features of the hadrosaurid jaw and proportions of the lower arm do not change with age, so Nipponosaurus is perfectly valid after all, and it sports features not seen in other members of its family, meaning it's a worthy name-bearer.
Etymology
Nipponosaurus is derived from "Nippon" (the Kanji name for Japan) and the Greek "sauros" (lizard). Kanji are the Chinese characters used in Japanese writing.The species epithet, sachalinensis, refers to its discovery on Sakhalin Island, which, at the time of publication, belonged to Japan but now belongs to Russia.
Discovery
The remains of Nipponosaurus were discovered in the "Upper Ammonites Bed" (Upper Yezo Group) in November 1934 during the construction of a hospital for the Kawakami Colliery of the Mitsui Mining Company at Toyohara-gun, Karafuto Prefecture, Japanese Saghalien (now known as Sinegorsk, Sakhalin, Russia).
The holotype (UHR 6590, University of Hokkaido Registration) consists of a left upper and lower jaw, various isolated skull elements, thirteen neck vertebrae, six back vertebrae, two hip vertebrae, a series of 35 tail vertebrae, a left shoulder blade, portions of both upper arms, most of the forearms, a partial hip (an ischium and a left ilium), and most of the hind legs. The skeleton is around 60% complete, but Nipponosaurus is one of the most poorly known lambeosaurines because the quality of bone preservation is a bit pants.
