This is a wonderful trace fossil. It is a set of 3 cruziana – trilobite trackways. One is large and well defined, the second is much smaller nearby and the third is slightly covered by matrix at the top.
It has two Rusophycus, trilobite resting burrows with one burrow at the end of the small cruziana. There are also several worm trails.
Along with the Cruziana and Rusophycus there is also evidence of a curved mud or sediment flow next to the trackway. These are trace fossils. Because there is no bone material or other hard evidence they are considered trace. A trace gives evidence of life but not the actual remains of the animal.
The Cruziana and Rusophycus were created by trilobites. The Cruziana is a trail made as the trilobites walked across the bottom of the ocean. The Rusophycus is a resting burrow. But this piece also shows a mud flow next to the tracks. Because there is current along the ocean floor ridges or ripple marks also appear. At times the Rusophycus are quite deep and it is believed it could be a feeding trace as well.
The Cruziana and Rusophycus, WHAT A GREAT PIECE of ocean floor history. It tells such a great story.