4" Large Spiny Walliserops Trilobite - Msissi, Morocco

Walliserops is a fascinating ancient arthropod that scoured the bottom of a shallow sea floor. It is placed in a genus of spiny, phacopid (acastid) trilobites and it is found in Lower to Middle Devonian (441-358 mya) rocks from Morocco. All species of Walliserops share the spectacular three-pronged "trident" that rises from the glabella. They also have horns over their eyes and intimidating spines along their backs.

Walliserops was highly specialized to deal with an oceanic wonderland in the diverse and dangerous Age of Fish. Specialization is a key difference from the more primitive “bugs” that emerged in the Cambrian.

Walliserops displays an unusual departure from bilateral symmetry. A notable example is the curved occipital spine of W. hammii, which takes a noticeable curl to one side. The regular development of these features in multiple specimens suggests a genetically controlled feature of the genus, not mutation or pathology. Some exceptions to bilateral symmetry can be explained by adaptations that allowed the trident to be held off the sea floor while walking.

The trident's function is an intriguing mystery. Many believe it was used to stir the ocean floor to better scavenge for food. Such a large adornment would have required significant energy and nutrient investment. Although a number of suggestions have been made (e.g. sensory apparatus, disguise or protection), many experts support an idea that the trident served as "horns" similar to present day beetles.

Morroco is an exciting place for discovering new and diverse species that lived in an ancient ocean that covered the northern reaches of the Sahara Desert. All three currently described Walliserops species come from the same strata near Foum Zguid in southern Morocco, though other locations have yielded new trilobites to study. This region is hailed as one of the great fossil treasure troves in the world.