According to this fossil record which of the following fossils would be the
least useful index fossil?
Period
MYA
Fossil
Carboniferous
363-290
Medullosa
Bjuvia
Medullosa
Sutcliffia
Archaeopteris
Sutcliffia
Permian
290-245
Spermopteris
Archaeopteris
Triassic
245-208
Leptodycas
Bjuvia
Jurassic
208-146
6 points
Androstrobus