Imagine, you are an avid collector of the weird and wonderful in the 19th century. Some of your favourite things to collect are fossils. To be able to see creatures from so long ago in such detail is amazing. You have a new specimen arriving today, and you are so excited to see it. It is a trilobite, and apparently it is an amazing specimen. You can even see it's eye lenses! These fossils are truly amazing things!
When I took this trilobite to show the children, they were enthralled by it. As the children explained, often fossils only show an incomplete animal, or the animal seems to just be sleeping. They had never seen a fossil where the animal was captured mid movement, or curled up like the trilobite. They had also never seen such detail in a fossil before. They were particularly impressed that they could see the eye lenses without even needing a microscope! What really captured their imagination though was the fact that the trilobite appears to be inside an 'egg'. The rock around the trilobite was carefully removed and fits perfectly back around the trilobite - like a 'prehistoric puzzle' as the children termed it.
Trilobites, a type of three lobed marine animal, are one of the most easily recognisable and popular types of fossil in the fossil record. They first appeared in our seas about 526 million years ago, and even the earliest trilobites actually show a really interesting diversity. As well as evolving into several (thousand) species, they actually appear to have had several species already when they first appeared and also appeared in several different parts of the world independently. Trilobites didn't become extinct until 250 million years ago, so they had over 270 million years to roam the seas!
Most trilobites lived in shallow water, wandering along the bottom and collecting up food. We think they probably ate 'detritus' (the leftover bits at the bottom of the sea) and used their legs to stir their food up in the sand, and move it towards their mouths. They probably weren't predators, because they didn't have big mandibles (hard jawbones) so they probably couldn't chew food and ate soft things instead. They had a hard exoskeleton (outer shell) which was well suited to becoming fossilized, so there are thousands of specimens still found today. This makes them fantastic fossils for children to collect because with so many available, children can find excellent examples within their price range. With about 17000 known species of trilobite to choose from, they also provide ample diversity for the collector to choose from!