Siegenian

The Siegenian was an epoch of the Devonian period spanning from 411.2 +/- 2.8 To 407 +/- 2.8 Ma. The term overlaps with parts of the internationally recognised Pragian and Emsian epochs, and although once widely used[1] is now deprecated.

References

  1. Niklas, K.J. (1985). "The evolution of tracheid diameter in early vascular plants and its implications on the hydraulic conductance of the primary xylem strand". Evolution (Society for the Study of Evolution) 39 (5): 1110–1122. doi:10.2307/2408738. JSTOR 2408738.