Bio 172 ~ General Time Line

3.8 bybp - oldest fossil prokaryotes

2.0-1.8 bybp - eukaryotic organisms (aerobic)

750 bybp - first Metazoan, oldest fossil of multicellular organism

500 mybp - all animals phylums

500 mybp - 1st vertebras

450 mybp - Chondrichthyes

• cartilaginous fish

425 mybp - 1st plants

• terrestrial primary producers

400 mybp - bony fishes by abundance of calcium and phosphate

360 mybp - Gymnosperms

• seed plants like Ponderosa Pines

350 mybp - amphibians, semi-terrestrial

• escaped predation by moving to land, still required moistness

300 mybp - 1st terrestrial vertebras

• amniotic organisms like crocs, birds, dinos

300 mybp - 1st Amniote Divergence (mammals)

280 mybp - 2nd Amniote Divergence (turtles)

230 mybp - 3rd Amniote Divergence, 1st Thecodont

• common ancestors to crocs, dinos, and birds

175 mybp - Caidphyleryx, feathered dinos

150 mybp - Archeopteryx, gliding corp.

125 mybp - Modern Bird (?)