Lemdadella is an extinct genus of redlichiid trilobites that lived during the late Atdabanian stage,[1] which lasted from 521 to 514 million years ago during the early part of the Cambrian Period.
At the midline, a ridge between the glabella and the border of the cephalon (a so-called plectrum) may be present.
[5] Lemdadella is currently the oldest trilobite genus known, dating back to about 521 million years ago.
The age and global distribution of Lemdadella are therefore of key importance for the Stratigraphy of the Cambrian.
[7] The following trilobite zones contain Lemdadella (Brackets contain geographic distribution):[7]