Differentiated Structures, But Which End Was Up?
Significant Diversity or Variations on a Single Theme?
Dawn of the Phanerozoic: Small Shelly Fauna and Trilobites
What Do We Choose as the Start of the Cambrian? Extinction of the Ediacarans? First appearance of the ”small shelly fauna”? –Late Proterozoic First trilobites? – Part of “Cambrian Explosion” –Lower, but not lowest Cambrian First trace fossils of trilobites? First evidence of mobility (burrows)? First burrows chosen