Even on a global scale, Hokkaido is a region which is rich in fossilized ammonites. However, this doesn’t necessarily mean that you can find them just anywhere in Hokkaido. Deposits of ammonites lie in the Ezo formation, which stretches from Cape Soya to Nakagawa, and through Haboro to Urakawa. Another fossil bed lies in the stratum which stretches from Kushiro to the Nemuro peninsula. Among these, Nishi-Ezo is known as an area that is particularly rich in fossil deposits.
Message from Ancient Times
That Hokkaido has an uncommonly large cache of fossils is not a well known fact. When we think of fossils, dinosaurs, trilobites and shells come to mind first. Prehistoric vegetation, or coal, is also another kind of fossil. Ammonites, prehistoric relatives to squid, are a particularly interesting class of fossils. The diversity of size and color found in the ammonites of Hokkaido make the deposits here a target for fossil fans and collectors. Hokkaido and the surrounding area lay at the bottom of the sea during the Cretaceous period, when ammonites were a common species. Changes in the earth’s crust have exposed the ammonite-rich Cretaceous strata. Many ammonites have been discovered in the Ezo formation which stretches through central-northern Hokkaido from Cape Soya to eastern Hidaka.
The picture above, the Haboro hana kaseki, or Flower of Haboro Fossil, is another fossil particular to this region. Only a few of these fossilized flowers have been found worldwide, and the Flower of Haboro is a most interesting specimen because its state of preservation is so perfect that the structure of the entire plant is visible. This fossil was formed 90 millions years ago; through it we can get a glimpse of life on prehistoric earth.