Serviseids

Serviseids are a group of extinct marine invertebrates that lived during the Paleozoic Era, specifically from the Cambrian to the Permian periods. They are classified within the phylum Echinodermata, making them distant relatives of modern-day starfish, sea urchins, and sea cucumbers. The defining characteristic of serviseids is their distinctive body plan, which typically involved a central disc from which multiple arms radiated. These arms were often long, slender, and branched, providing a large surface area for filter feeding.

The fossil record of serviseids is primarily composed of their ossicles, which are small calcareous plates that formed their internal skeleton. These ossicles are often found in great abundance, suggesting that serviseids may have lived in dense communities. Their feeding strategy involved extending their arms into the water column to capture suspended organic particles. The exact placement and lifestyle of serviseids are still subjects of ongoing scientific research, with some evidence suggesting they were attached to the seafloor while others may have been free-swimming.

The evolutionary history and eventual extinction of serviseids remain areas of interest. They represent a significant component of ancient marine ecosystems, and their disappearance marks one of the major extinction events in Earth's history. Understanding serviseids helps paleontologists reconstruct the biodiversity and ecological dynamics of the Paleozoic oceans.