Devonian

The Devonian period lasted roughly 419–359 million years ago. Long before the Sahara became a desert, this region was connected to warm seas. Over time, muds and sands on the sea floor hardened into rock and preserved fossils inside it.

Erfoud during the Devonian

Think of the area around modern Erfoud as part of an ancient marine world: shallow-water shelves, sea-floor habitats, and changing coastlines over millions of years. That’s why Devonian fossil layers here are strongly marine—many of the classic “Erfoud fossils” from this chapter come from ocean life, not land animals.

Because these fossils formed in sea-floor sediments, you’ll often find fossils preserved in rock matrices that once were mud, sand, and carbonate materials. The desert exposure today makes those layers easier to access and study.

What was living back then?

Devonian layers in Morocco are famous for marine fossils. Depending on the site, you may learn about (and sometimes find) fossils such as:

• Trilobites — classic segmented sea animals from Paleozoic oceans.
• Ammonoids (often called goniatites in Devonian contexts) — early relatives of modern cephalopods found as coiled shells.
• Crinoids — sea-floor animals sometimes preserved as small “ring” segments.
• Brachiopods — shell-bearing marine animals that were very common in Paleozoic seas.
• Corals and reef-life fragments — clues that some areas supported reef-like habitats.
• Early fishes — the Devonian is famous for fish evolution, and fish remains can be part of the wider story of this era.
• Other marine shells and sea-floor fossils — depending on the layer and location.

These fossils are a window into a time when the region’s story was written in water, not sand.