Complex sentence: One 2009 study of "Stegosaurus" specimens of various sizes found that the plates and spikes had delayed histological growth in comparison to the skeleton and when the dinosaur reached maturity, growth in the osteoderms greatly increased.
Split into simpler sentences: One 2009 study of "Stegosaurus" specimens of various sizes found that the plates and spikes had delayed histological growth in comparison to the skeleton. The authors suggest that when the dinosaur reached maturity, growth in the osteoderms greatly increased.