Hi!
Whether you can help estimate how long ago the last common ancestor of
Polychaeta or Sipunculida lived ("crown group")?
I try construct the diagram of classis amount as function of time (diagram
of dependence N=f(t), where N - amount of Existing classis at time t).
Unfortunately I am not biologist and can not in any way find some points (in
paticular - Polychaeta and Sipunculida ).
Or may by you know who it know?
Whether you can give subjective astimation of it time?
Beforehand thanks,
Fomin Alexey.
