Phacops speculator trilobite 44mm unearthed in the western Sahara desert of north Africa. This genuine and superbly preserved trilobite seemingly clinging to a miniature mountain shows very well on the original fossil rock bed. The invertebrates carapace picked out in natural black fossil chitin. Thus revealing the attributes of this type of fossil arthropod the Phacops speculator trilobite. The many turbucles covering the entire fossil carapace, the three longitude parts or lobed and segmented carapace gave the trilobite it name, from the Greek, trilobite meaning three lobes. This carapace fossilised while the softer body parts were almost always lost to the ravages of fossilisation, predation or bacterial breakdown. The enlarged eyes are are fascinating with a myriad of lenses, the preservation is such that the individual lenses may be distinguished without the aid of a magnifying glass. This trilobite displays a very inflated exoskeleton which lifts the trilobite from the base rock with a good three dimensional posture, as if the extant individual is still alive and able to haul itself over the rock.
The Phacops speculator trilobite has been cut from the rock seam of the fossil bed in the fossil site and taken from the field to a lab where all the real work of preparation is carried out. In the fossil bed or seam the carapace of the trilobite absorbs minerals into the carapace or exoskeleton which is made up of a very high degree of calcification, i.e. primarily consisting of low-magnesium calcite, a carbonate mineral and the most stable polymorph of calcium carbonate. The chitin carapace scholars believe is formed from chitin fibrils, long chains of protein subunits, chitin is translucent, very flexible and resistant, in arthropods chitin is modified becoming hardened proteinaceous which develops much of the carapace.
This Order Phacopida, Phacops trilobite segments have been engineered by evolution to interlock and provide armour with flexibility, under this chitin exoskeleton the arthropod defended its soft body parts now lost to the ravages of the fossil bed. In this type the tubercles seen on the carapace or exoskeleton have no spines,in other types spines evolved giving the invertebrate more defense perhaps? We do not know positively,some theorist suggest they could also be for a feel or sensory defense. Amazing and intriguing,we have so much to learn from these little bugs! This arthropod has three lobes longitudinally, these name it, from the Greek, tri-lobite,three lobes which run into the pygidium (tail), also the three parts of the exoskeleton which often separate in the fossil beds are the glabella (head), thorax and pygidium. These make up the complete carapace or exoskeleton, this is shed in the animal's lifetime and we find them enrolled which could possibly have been a defence posture or the shed carapace fossilised.