The thickening of the cortical section of the bone and the compaction of bone in the terminal tail-spikes in old adults suggest that they were used as defence weapons, but not until an ontogenetically late stage. The development of the large axial channel in old adults from small canals in young adults, facilitated the further enlargement of the spikes by increasing the amount of nourishment supplied.
The thickening of the cortical section of the bone and the compaction of bone in the terminal tail-spikes in elderly individuals suggest that they were used as defensive tools, but not until a late stage in their development. The growth of the large axial channel in elderly adults from small canals in younger adults facilitated further enlargement of the spikes by increasing the amount of nourishment supplied.