Elrathia Trilobite with Two Types of Fossil Algae

Description: The first fossils of multicellular green algae appear in the Cambrian strata of the early Paleozoic Era. Yuknessia as shown here was a thin, frond-like green, carbonaceous algae resembling modern kelp. Complete algal fossils, identified as Yuknessia simplex and Margaretia dorus have also been found in the Burgess shale of Canada; both genera have been classified as Chlorophytes, a distinct branch of green algae from the Streptophytes that eventually gave rise to the land plants. This taxon has not been well studied. There is another, globular form seen as well; neither photograph well, but will be apparent to the eye when seen in natual light at a low incident angle.

The trilobite is a common one to the Wheeler Formation, and makes a stark contrast to the alge found on this plaque.

Reference: The Fossils of the Burgess Shale by D. E. Briggs, et al.