GEM Acernaspis Trilobite with Preserved Soft Tissue

Description: The trilobite presented here is rarely offered since few have ever collected in this region, but what makes this one truly exceptional is the fact that it exhibits a type of soft tissue preservation I have only seen once before. During the course of finish work along the edges of the thorax the preparator was astonished to see evidence of limbs and antennae preserved in a combination of iron (some flakes of pyrite) and calcite, an unprecedented occurrence. Segmentation of some limbs, claw feet, and annulated antennae are all evident. To the best of my knowledge no other example of this type of preservation has been reported in this taxon. And if that were not enough, there are several spots of preserved coloration in the form of chromatophores seen on the left pleural lobe. This extends preserved coloration in the phacopids back into the Silurian (see my other offerings for examples of Eldregeops) It is only through painstaking work with 50 nanometer powder that the features here were brought to light without complete destruction during the preparation process.

Reference: Palaeontographica Canadiana, Monograph 22, 2004.