Lower Cambrian fossil Volborthella: The whole truth or just a piece of the beast?

• Published in: Geology (Boulder) 1993-09, Vol.21 (9), p.805-808
• Main Authors: Signor, Philip W, Ryan, Dallas A
• Format: Article
• Language: English
• ISSN: 0091-7613
• DOI: 10.1130/0091-7613(1993)0212.3.CO;2

Early Cambrian faunas are rich in strange and distinctive fossils that are difficult to interpret or to classify. The small, conical fossils assigned to the extinct phylum Agmata, and the arguments surrounding their affinities and paleoecology, are a classic example of this problem. Volborthella are commonly found in Lower Cambrian strata of North America and in coeval units on the East European platform. These agglutinated fossils are traditionally interpreted as the complete skeleton of individual animals. However, a newly discovered fossil from the White-Inyo Mountains of eastern California demonstrates that Volborthella was a bilaterally symmetrical animal bearing multiple pairs of conical agglutinated sclerites. Volborthella, as traditionally defined, was one of many sclerites covering a relatively large metazoan, an Early Cambrian armored worm or mollusklike animal, and is the only known metazoan with a scleritome composed of agglutinated elements. This discovery ends more than a century of misinterpretation of this enigmatic Early Cambrian fossil.