Trilobite - Natural Fossil - Rough - Original Stone - 13 cm

Original piece from Morocco. It consists of the piece and its lid. It is presented raw as it was extracted.
Trilobites1 (Trilobita, from the Latin, "three lobes") are a class of extinct arthropods, within the subphylum Trilobitomorpha. They are the most characteristic fossils of the Paleozoic Era (Primary Era). Nearly 4,000 species have been described.2

They appeared in the Cambrian period (at the beginning of the Paleozoic, about 540 million years ago), and began to diversify already in the lower Cambrian. After the mass extinction at the end of the Cambrian, only the forms that inhabited pelagic, deep-sea environments survived. During the Ordovician they reached their maximum diversity and occupied almost all marine ecological niches. From the Silurian they presented few changes, until in the middle and upper Devonian crises they suffered an important reduction, extinct all the orders except Proetida. During the Carboniferous the representatives of the group are scarce and restricted to reef environments. The last trilobites, now only inhabitants of shallow waters, disappeared during the Permo-Triassic boundary crisis (about 250 million years ago). Therefore, their presence on Earth lasted throughout the Paleozoic, more than 300 million years. Trilobites are so abundant and have been so thoroughly studied that they are probably the best-known group of fossil animals.

initially se were considered ancestors of crustaceans (especially the terrestrial sowbug, which shares certain characteristics in common) or even of all arthropods (since they were the first to appear in the fossil record). Today they are considered as an independent group, separated from the mandibulates and chelicerates.