Unseen Eons is an illustrated guide to the parts of Earth’s past that no camera ever saw: animals that died out before photography, continents that broke apart hundreds of millions of years ago, the days when an asteroid struck or the oceans froze, and the other kinds of people who lived alongside our ancestors.
Everything here is known from evidence that survived: bones and teeth, footprints in volcanic ash, frozen carcasses, the chemistry of old rocks, magnetism locked into lava, and DNA pulled from fossils. The pages set out what that evidence shows, and the pictures show what it might have looked like.
The pages
Every page is written by hand from named sources, listed at the foot of the page and linked from each fact. Most of the numbers come from the published studies behind each find, from natural history museums and geological surveys, and from the Wikipedia articles that summarise them. Where estimates disagree, as they often do for the size of an animal known from a few bones, the page gives the range and says who measured what. Where an idea is a hypothesis rather than a settled result, the page says so.
Dates are given in years before the present. Large numbers use a space rather than a comma to separate thousands. The ages of the geological periods follow the International Chronostratigraphic Chart, and the colours used for each period on the timelines are the chart’s own.
The pictures
Every image on this site is a reconstruction. None of them is a photograph, and none should be read as one. Each page says what its pictures are based on and which parts are imagined, such as the colour of an animal known only from its skeleton. How the pictures are made, and what you may do with them, is explained on the illustrations page.
Corrections
If a number, a date or a claim on any page is wrong, please write to [email protected] with the source, and it will be fixed.
Who runs this
Unseen Eons is run by Samu Leino in Finland. It is a sister site of Unseen Cosmos, which does the same for places in space. The site has no accounts, no sign-up and no comments. What little data it collects is described on the privacy page.