Step 1: Compare ferns and gymnosperms.
Ferns are pteridophytes, whereas gymnosperms are seed plants.
Both groups show some similarities, but they also have important differences.
Step 2: Check common features.
Archegonia are present in ferns and also in gymnosperms.
Circinate vernation is commonly seen in young fern leaves and is also seen in some gymnosperm members like cycads.
Ramenta are brown scaly hairs and may occur in both groups.
Step 3: Identify the non-common feature.
Ovules are present in gymnosperms because they are seed plants.
Ferns do not produce ovules because they reproduce by spores.
Therefore, presence of ovules is not a common feature of both ferns and gymnosperms.
Step 4: Final conclusion.
Thus, the correct answer is
\[
\boxed{\text{Presence of ovules}}
\]