Trilobite
Trilobite Information
Trilobites, a fascinating group of extinct marine arthropods, are easily recognized by their distinctive three-lobed, three-segmented form. These marine creatures first appeared around 521 million years ago during the Cambrian Period (538.8 to 485.4 million years ago), dominating the ancient seas. Despite their decline in subsequent geologic periods, some forms persisted into the Permian Period (298.9 to 251.9 million years ago).
Originating likely during the Ediacaran Period (635 to 538.8 million years ago), trilobites are closely related to an organism known as Spriggina, found in Precambrian shallow-water marine deposits in Australia. Trilobites are often used for stratigraphic correlations due to their abundance and diversity in the fossil record.
Trilobites had a segmented body with three regions: the cephalon (head), thorax, and pygidium (tail). Their three body lobes included a central axial lobe flanked by lateral pleural areas. Like other arthropods, trilobites had an external exoskeleton composed of chitinous material. To grow, they shed this exoskeleton, resulting in fossils that are relatively common.
These ancient creatures continue to captivate paleontologists and fossil enthusiasts alike, providing valuable insights into Earth’s early marine ecosystems.
Trilobite Facts
- Extinct Marine Arthropods: Trilobites were marine arthropods that lived during the Palaeozoic Era. They first appeared around 521 million years ago.
- Rolling Up: Trilobites could roll up into a ball, similar to present-day woodlice, for protection.
- Size: Sizes ranged hugely although the average trilobite is around 3-6cm long
- Global Distribution: Trilobite fossils have been found all over the world.
- Diverse Lifestyles: Some trilobites burrowed in sediment, others crawled on the sea floor, and some swam in open water.
- Diet: They were detritus feeders, scavengers, predators, and possibly filter feeders.
