130 likes | 259 Views
Ediacarans, Small Shells and the Dawn of the Phanerozoic. Edicaran Biota. First fossils of multicellular organisms Some controversy Multicellular life? Colonies of single cells? Definitely not single cells Signs of tissue differentiation Advanced symmetry. Ediacaran (Vendozoan)Biota.
E N D
Edicaran Biota • First fossils of multicellular organisms • Some controversy • Multicellular life? • Colonies of single cells? • Definitely not single cells • Signs of tissue differentiation • Advanced symmetry
Taphonomy of theEdicaran Biota • Soft/firm bodied? • Molds and casts in coarse sandstone • Facies preference? • Taphonomic bias?
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