Zoophycos: international trace fossil of mystery
Zoophycos imprints are found all over the world and their remains date from the Cambrian through to the Holocene epoch. Descriptions of these remains date from the 19th century, and they appear as ribbed, spiral, or fan-shaped structures measuring up to 1.5 metres across. They are some of the most preserved and most common of marine organisms, but they are also the most mysterious. Why? Because while scientists can see that Zoophycos are the remains of burrows, they have no fossilised remains of the creature to verify the kind of behaviours that would generate these burrows.
The creatures that produced Zoophycos fossils lived on the deep-ocean floor, and there are a couple of different ideas as to how they fed. Many examples of the fossil suggest that the animals lived beneath the surface of the ocean floor’s ooze, where they built layers of the burrow along food-rich zones, and through which they stored fecal pellets. Other examples of Zoophycos appear to have been dug by animals that fed atop the surface of the ooze; yet other specimens have tunnels through areas of stored fecal pellets.
Wherever on the ocean floor Zoophycos thrived, these fossils show animal behaviour that suggests the organism was changing its ecosystem in order to deal with a sporadic food supply.
Photo credit: TEL
Two tigers. Yantai, China, autumn 2013.