Nipponosaurus

Nipponosaurus (meaning "Japanese lizard") is a lambeosaurine hadrosaur from Sinegorsk, Sakhalin Island in Russia, part of Japan at the time of naming. The type and only species is N. sachalinensis, known only from a single juvenile specimen discovered in 1934 and named in 1936, by Takumi Nagao, with further material of the same individual found in 1937.[1][2][3]Since then, the taxon has been largely ignored, and it's validity has been doubted, with synonymy with other Asian hadrosaurs or status as a nomen dubium being suggested. Redescriptions from 2004 and 2017, however, have supported recognition as a distinct species.[2][4][5] Dating the only specimen has been difficult, but based on associated mollusc taxa, the species likely lived sometime in the upper Santonian or lower Campanian, around 80 million years ago.[4][5]