Hello,
Through the course of a class discussion on the subject of ferns
and fern allies, a fellow student posed an interesting question that no
one was able to answer. I was wondering if, perhaps, one one you might be
able to?
The question is whether there were sphenophyta that were not
equisetum that may be extinct now, or whether sphenophyta have always been
equisetum?
Any takers?
