Diminutive Erbenochile Moroccan Trilobite

Description: Elegant example of a member of the Order Phacopida, Superfamily Acastoidea with many fine details present. Once known in the trade as “Big Eye”, this one is actually Erbenochile, and has recently become commercially available in limited quantities. The most diagnostic features of this taxon are the high “eye-towers”. Fortey and Chatterton described Erbenochile erbeni in September 2003 from a single commercially- prepared specimen, and it created a stampede among collectors. The “wrap around” eyes gave a good panoramic view of the trilobite’s environment, allowing it to keep alert for predator and prey alike. Since fish had recently evolved true jaws, any advantage a prey species could derive would place it at an advantage. This one has been prepared with the axial spines all freestanding, quite an achievement from such hard matrix with such a small specimen. Note the exceptional eye facets seen here, a feature that is difficult to prepare well due to the matrix. Some 10 years ago a second species, Erbenochile issomourensis, was described with the main differences being a lower eye tower and lack of a sunshade. It is believed that this new species lived at greater depths which eliminated the need for the eyeshade of Erbenochile erbeni. In looking at this one if the location of Foum Ziguid was not known as the source of this example one would conclude that this one was the species issoumourensis due to the lower number of eye facets. The diminutive size of this specimen is a clue. It is roughly half the size of typical specimens because it is a subadult example. I discussed the eye facet issue with a researcher and was told that while it has not been studied in Erbenochile, perhaps due to the paucity of small specimens, it is indeed known that other types of trilobites display this same feature. This is an excellent opportunity to obtain such and unusual example at a bargain price.

A specimen of the very rare Erbenochile issomourensis may be seen here, and here is another Erbenochile erbeni specimen.