Figure 1.

Two New Fossil Root Apices from the Carboniferous Period

(A and A′) Thin section 76, shown by permission of the Oxford University Herbaria. (A) Apex 76.1 tentatively assigned to Lyginopteris oldhamia. (A′) Apex 76.1 is shown with the main tissue types color coded (yellow, root cap; blue, epidermis; pink, differentiated cells at the position of the promeristem; orange, cortex; brown, endodermis; and green, procambium).

(B and B′) Thin section R646, shown courtesy of the Manchester Museum, The University of Manchester. (B) Lyginopteris oldhamia root apex discovered by Stopes and Watson [3]. (B′) L. oldhamia is shown overlaid with colors to represent the major tissues types as shown in (A′).

(C) Thin section 81, shown by permission of the Oxford University Herbaria. Holotype of the root apex of Radix carbonica (produced by the assembly of a series of continuous images of the root apex).

Scale bars, 200 μm (A and B) and 500 μm (C).