Grammites

Grammites is a genus of extinct arthropods belonging to the order Agnostida. These small, primitive trilobites are known from the Cambrian period, specifically the Middle Cambrian to Late Cambrian stages. Grammites are characterized by their tiny size, typically only a few millimeters in length, and their almost complete lack of facial sutures, a common feature in other trilobite groups. They also possess a distinctive shield-like exoskeleton, composed of a cephalon (head) and a pygidium (tail) that are nearly equal in size and often have a similar shape. The glabella, a central raised area on the cephalon, is usually reduced or absent in Grammites.

Fossil specimens of Grammites are found in marine sedimentary rocks worldwide, indicating a widespread distribution during the Cambrian. Their small size and lack of prominent features have made them challenging to study, but their presence in different geological strata has been useful for biostratigraphy, helping to date rock layers. The exact lifestyle and ecological role of Grammites are not well understood, though their small size and simple morphology suggest they may have been planktonic or nektonic organisms, drifting or swimming in the ancient seas. The genus Grammites is a significant component of the Cambrian fossil record, providing insights into the early evolution and diversity of trilobites.