By one of those happy coincidences that you sometimes get, today saw the publication of not one but two dinosaur ontogeny papers: this morning I was sent a copy of Woodruff and Fowler (2012) on ontogenetic changes in the bifid spines of diplodocoids, and tonight I was alerted to Werning (2012) on Tenontosaurus growth trajectories based on osteohistology. It’s interesting to compare them.