Trilobitomorphans

Trilobitomorphans are a group of extinct arthropods that lived during the Paleozoic era, from the Cambrian to the Permian periods. They are characterized by their distinctive trilobite-like body plan, which includes a segmented body with a cephalon (head) shield, thorax, and pygidium (tail) shield. Trilobitomorphans are believed to have been one of the most successful and diverse groups of early arthropods, with over 20,000 species described to date.

The earliest trilobitomorphans appeared during the Cambrian explosion, around 530 million years ago. They were one of the first groups of arthropods to evolve, and their success can be attributed to their hard exoskeletons, which provided protection and support. Trilobitomorphans were also well-adapted to life in the oceans, with many species living in shallow, warm waters.

The most well-known group of trilobitomorphans is the trilobites themselves, which are characterized by their three-part body plan. However, there are also many other groups of trilobitomorphans, including the phacopids, redlichiids, and ptychopariids. These groups share many similarities with trilobites, but also have unique features that set them apart.

Trilobitomorphans went extinct at the end of the Permian period, around 252 million years ago. The cause of their extinction is still debated, but it is likely that a combination of factors, including climate change and competition from other groups of arthropods, played a role. Despite their eventual extinction, trilobitomorphans left a lasting legacy in the fossil record, and their study continues to provide valuable insights into the evolution of early arthropods.