Have we ever seen a stone shaped like a snail, a footprint marked in rock, or a bone that seems too large to belong to any modern animal? All of these, without us knowing it, are messages from the past that reach us through time—what we know as a fossil. But what are they really?
What exactly is a fossil?
Fossils are the organic remains of beings from prehistoric times. They can be found in sedimentary terrains, preserved through petrification processes or other natural mechanisms.
Fossils can be plant or animal remains. Sometimes they consist of complete organisms or parts of them; other times, they are simply traces. Plants, for example, have left various traces of their vegetative structures. Animals, on the other hand, have left their hard parts: teeth, shells, and so on. In exceptional cases, soft parts have been found: muscles, kidneys, and more. On even rarer occasions, entire animals have been discovered, such as the fossilized mammoths covered in ice found in Siberia. Insects have also endured as fossils thanks to a resin called amber that preserves them perfectly.
Therefore, we can understand that a fossil—whether in amber or even at the bottom of the sea—is any remains or trace of a living being that existed more than 10,000 years ago and has been naturally preserved in rocks, ice, or crystal. We should understand that they are not only dinosaur bones (although those are the most famous). They can also be: footprints of animals that walked on ancient mud, burrows where prehistoric creatures lived, fossilized feces called coprolites, or insects trapped in amber, like in that scene from Jurassic Park that we all remember.
Types of fossils, or a quick guide to recognizing them
- Hard remains: Bones, teeth, shells—like the ichthyosaur found by Mary Anning.
- Molds and traces: Dinosaur footprints or leaf impressions in stone.
- Amber fossils: Insects preserved in tree resin for millions of years.
-Living fossils: Animals that have not changed in millions of years (like the coelacanth).
Curiosities that will make us look at stones with different eyes.
- The oldest fossil: is 3.7 billion years old and consists of microscopic bacteria.
- The largest fossil: is a 20-meter whale found in Peru.
-Not all fossils are bones: coprolites (fossilized feces) have revealed what dinosaurs ate.
- Fossils can be preserved in ice: like the woolly mammoths of Siberia.
- The first documented fossil: was a mastodon in 1726… and it was mistaken for a human giant.
- The most expensive fossil in the world: was sold for 2.3 million dollars.
Now that we know what fossils are, we will better understand why the story I will tell in my next post is so important. It will be about an extraordinary person who challenged her time, who proved that she not only found rare stones but also read the Earth's archive with her own hands—the same hands with which she unearthed sea monsters that no one had ever seen, and without knowing it, she was founding modern paleontology, making us understand that: every fossil is a page from a book we have not yet finished reading.
Besides the famous dinosaurs and the mosquitoes in amber, what other fossils do you think should be better known? Tell me in the comments. I would love to read you.
