Hederellids are extinct colonial animals with calcitic tubular branching exoskeletons. They range from the Silurian to the Permian and were most common in the Devonian period.
Hederellids are extinct creatures that lived during the Silurian to Permian periods and were most prevalent during the Devonian era. They had a distinctive skeletal structure made of calcium carbonate tubes that branched out like a tree.