Trilobite Color Patterns

     Whatever your level of interest in the trilobite world, one thing should become readily apparent as you pore over the contents of this web site -- these ancient arthropods display a surprising diversity of color. Depending on where they've been found, and what minerals have most influenced their fossilization process, the rock-hard shells of these Paleozoic relics can appear as black… white…tan… brown… even the occasional red, orange or yellow. Some actually present a mottled shell pattern akin to a calico print. 
     Virtually every color contained within Mother Earth's natural palette can be found represented in the calcified remains of a trilobite's preserved exoskeleton. From the golden hues that distinguish the myriad species drawn from the Ordovician layers surrounding Russia's Wolchow River, to the ghostly white preservation that defines Portugal's Valongo formation, to the charcoal grey that characterizes the Silurian material found in upstate New York's Rochester Shale, the coloration of trilobite fossils is nothing if not disparate. But an inherent question then emerges; do any of these colors represent the actual markings that trilobites may have displayed during their long-ago lifetimes in those antediluvian seas? 
     Much like modern fish, insects or birds it's not difficult to imagine trilobites of different genus' swimming through those primal oceans exhibiting a wide variety of contrasting colors. Indeed, distinctive coloration seems to be a unifying characteristic within the animal kingdom -- and what is true today seems only logical to have been true when trilobites first ruled the seas some half billion years ago. Perhaps those Paleozoic color patterns were used as part of a mating ritual, or to find members of one's clan amid the murky sea depths. 
     Unfortunately, we will probably never uncover a definitive answer to this compelling riddle surrounding early life on our planet… but then again, maybe we will.  In fact, a smattering of recent evidence has begun to shed a few promising rays of light on the somewhat controversial subject of trilobite color patterns, and whether they actually persist within the fossil record.
   The fact is that we know so little about the color patterns of trilobite exoskeletons for a very good reason -- hundreds of millions of years after their demise, the pigments that created those colors in life have been replaced or “bleached” by the invading minerals that are essential to the fossilization process.  But a small number of recently studied specimens, including examples of Scabriscutellum scabrum and Thysanopeltis acanthopeltis from the Devonian outcrops of Germany, display what appear to be well-defined markings adorning their disarticulated pygidia. These designs have persuaded some scientists that they reflect actual trilobite color patterns -- though other paleontologists still seem a tad reticent to embrace such a radical concept, believing that these markings may be a direct result of the mineralization process itself. 
     Along with this minimal evidence supporting the notion of color markings, the fossil record has possibly preserved another in-life characteristic of the trilobite carapace… spots. What role these dark, circular features may have played as trilobites darted in and out of 400 million year old reefs is still very much open to speculation and debate, but the presence of those distinctive markings now appears irrefutable. Indeed, examples exist of the Devonian phacopid, Eldredgeops crassituberculata from the renowned Silica Shale of Ohio, as well as similar trilobite-types found in the 400 million year old sedimentary rocks in New York State, whose shells exhibit a series of distinct, small black circles. It has been speculated by some that these spots may represent a type of primitive camouflage, though others feel that they may simply be the dorsal reflection of the trilobite's internal muscle attachments.
       So it seems that while the trilobite fossils that adorn private collections and museum shelves often display a magnificent array of colors, in all likelihood none of those shades represent the trilobite's true hue. Perhaps one day we will uncover a Paleozoic layer in which the contained trilobites reflect life-like shell coloration. Until that time, however, all we can do is speculate and wonder about this intriguing mystery of the ancient past.

This New York State phacopid's shell exhibits a series of distinct, small black circles. It has been speculated by some that these spots may represent a type of primitive camouflage, though others feel that they may simply be the dorsal reflection of the trilobite's internal muscle attachments.