521 MILLION YEARS AGO...

Like an explosion of shelled confetti, trilobites crawled their way into existence during the early days of life on our planet. Not only did these early pioneers of the primordial Earth survive, they thrived! They flourished for almost 280 million years, and their fossils can be found on every single continent.

Just for reference, humans have only been on Earth for about 200,000 years. So how did these seemingly simple creatures become one of the most ubiquitous groups of animals during the early years of life on our planet? Glad you asked.

Ocean life was drastically different when trilobites made their way onto the scene. Most sea creatures were blind and comparatively simple compared to today's vast and complex inhabitants of the watery depths. The trilobite, however, was nature's cutting-edge leap into advanced forms of life and was among the first organisms to develop complex eyes.

These eyes weren't like the squishy eyeballs you and I have. Trilobite eyes had calcite lenses (calcite is a rock-forming mineral that we often find in crystal formations), which allowed their eyes to be specifically tuned to see clearly in set directions. They literally had crystals for eyes! How cool is that?

Considering most ocean life was still attempting to master the prehistoric seeing eye-chart, trilobites had a huge advantage. Along with their ability to spot their next meal, they also developed natural defenses against other predators, such as large, pointy spines, the ability to roll into a ball much like a pill bug, and hardened exoskeletons. 

WHAT HAPPENED TO THE TRILOBITES?

Even with their seemingly endless bag of tricks, trilobites died out 250 million years ago during what is called "the Great Dying." Around 90% of all life on Earth suddenly perished in a cataclysmic event, the exact causes of which are still debated. Theories range from massive volcanic eruptions and a titanic meteorite crashing into Earth to an early-day Y2K.

However it happened, it did leave us with plenty of fossil trilobites, but these crafty arthropods had one more ace up their sleeves.

Most trilobite fossils are actually the molted exoskeletons of the creatures, left behind from some ancient growing pains. Unlike humans, whose skin grows and flexes with our changing bodies, trilobites had to shed their old skins in order to grow larger. Thanks to this somewhat disturbing method of getting swole, we have a wide plethora of trilobite specimens to study and ogle at.

While they may be just a page in the ledger of nature, trilobites may provide vital clues about the evolution of life as we know it. They also look really cool on your desk.