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.
Referencesedit
^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. 39 (5). Society for the Study of Evolution: 1110–1122. doi:10.2307/2408738. JSTOR 2408738. PMID 28561493.
