“An estimated four billion species emerged on our planet in past eons. But at least 99% of them died out, way before humans spoke the first words. The vast majority of all the different species that ever existed are so utterly deleted that they have become part of the “unknown unknown” part of the past, lost to us forever…”
This illuminating Kurzgesagt video shares how we know what we know about planet Earth’s biological past and why we don’t know what we don’t know.
What conditions are required to fossilize a dead animal and then protect it for hundreds of millions of years? How many creatures have we yet to know and imagine because their remains didn’t meet those exact circumstances?
A promo for Kurzgesagt merch, a way to support the channel, starts around 9m55s. From the video:
“We know a lot of species are lost forever just because of the environment they lived in. For example, lush jungles basically prevent fossilization as the chances that an animal will be buried here is minimal. Countless scavengers of all sizes break down freshly deceased animals extremely quickly and the soil is often so acidic that bones are dissolved. And so fossils of dinosaurs from jungles are practically nonexistent.”
“Today half of all known species live in the few remaining rainforests that only cover 2% of Earth’s landmass. Millions of years ago when dinosaurs roamed Earth, jungles covered much more of the planet. So besides some insects and other small animals trapped in amber, there should be millions of species that emerged and vanished, without leaving any trace.
And what don’t we understand about the creatures we do know? What conclusions can we draw from animals we know today? Did some dinosaurs have elaborate mating dances like birds of paradise? Did some mostly rest and play like lions? What colors and patterns might they have flaunted? What behaviors will forever remain unknown?
And would animals in today’s world be lost in the fossil record? Kurzgesagt waxes philosophical about these possibilities, and ties the past to our present and future:
“Most wild animals alive today will in all likelihood not leave fossils behind and also just disappear forever. We can do something about that though – instead of accelerating the extinction we are witnessing we could become the guardians of life and preserve it where we find it. If possible in the wild, if not then in museums, movies, and in our minds.
“Because as amazing as our imagination is, and as fascinating to think about the animals that are part of the unknown unknown – it is even better to witness them in the present. The land that we actually inhabit, where we get to experience life as it happens.”
Related reading from 2016: Most species that disappear today will leave no trace in the fossil record.
Watch these hand-picked videos next:
• What exactly happened on the day that dinosaurs died?
• How do we know what color dinosaurs were?
• The Crystal Palace Dinosaurs: The facts and fiction over 160 years
• The Cornell Lab of Ornithology‘s Birds of Paradise project
• Natural History Museum, a future imagined by Kirsten Lepore
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