Trilobite Fossils Over 500 Million Years Ago Found Well-Preserved Under Volcanic Ash in Morocco

Trilobites are extinct animals that lived in marine environments hundreds of millions of years ago, known for their appearance resembling the helmet of Darth Vader.

They first appeared about 542 million years ago during the beginning of the Cambrian Period. The name "tri-lo-bite" means three-part-body in Latin, describing that these extinct marine arthropods are covered with segmented exoskeletons.

Despite the known resilience of trilobites against the forces of nature, they mysteriously disappeared by the end of the Permian Period around 251 million years ago. In a prehistoric mass extinction phenomenon known as the "Great Permian Extinction."

Scientists discovered the oldest trilobite fossils dating back about 550 million years ago. Since then, biologists have described over 20,000 trilobite species in the last 200 years.

Now, a new study makes a breakthrough discovery in Morocco, where the ancient remains of the arthropods have been well-preserved by volcanic ash. It is for this reason that researchers involved in the study called these specimens "Pompeii" trilobites. This attribution is in comparison to the inhabitants of Pompeii, Italy, where the majority of them perished following the eruption of Mount Vesuvius in 79 AD.

Trilobite Extinction Mystery

Prior to the trilobite extinction event, these ancient arthropods not only survived for almost 270 million years but also thrived on Earth, filling the planet's oceans from the Early Cambrian until their demise during the Late Permian periods, according to the American Museum of Natural History (AMNH). While there is no single definitive cause of their extinction, scientists believe it was caused by many factors.

However, evidence shows that the series of natural disasters during the Great Permian Extinction, which killed almost all marine life at that time, is the greatest contributor to the trilobites' demise. In fact, more than 96% of all oceanic species and even 70% of terrestrial organisms died during the mass extinction event, which included the blocking of sunlight following multiple volcanic eruptions.

Also Read: Trilobites Possessed Clasper-like Limbs for Mating, According To Fossil Discoveries

Trilobite Fossils in Morocco

To better understand these ancient marine animals, an international team of scientists, including from France and the United Kingdom, went to the High Atlas of Morocco and discovered almost whole 500-million-year-old trilobite fossils. The excavated specimens retained their quality due to rapid volcanic ash entombment, according to their study published in the journal Science on Thursday, June 27.

Being buried under volcanic ash, the fossilized remains of trilobites were able to retain their 3-dimensional (3D) anatomy. These recent findings contrast with previous discoveries of related trilobite specimens which are 'flat' and lose their biological features when the animals are still alive.

In a YouTube video, posted by the channel Science X on Friday, June 28, researchers present a 3D image of the recently unearthed Moroccan trilobite fossils, which contains their bodies, legs, and even their hair-like features along their appendages. This new fossil evidence further confirms that trilobites are unique in their way.

Related Article: What Did a 465-Million-Year-Old Trilobite Eat? Synchrotron Tomography Gives a Clue