Now what we outside observers know,and Marcus didn't,was that the life cycle of a dragon
has nothing to do with time,but metabolism.
Simply put,Marcus's fate was based on how much he ate,and the quicker he
ate and the more he ate,the faster his development into a adult dragon
would occur.For him to turn into a huge well muscled male adult would
require he consume vast quantities of prey,for him to turn into a smaller
female adult,however still well muscled,fertile and built to carry heavy
dragons eggs resting on that wide pelvic cradle of hers,required less food,but more
plant matter then animal prey.
And if Marcus didn't find anything at all,he'd remain a more gender neutral
dragonet,able to walk easily on both 2 legs or four,due to the fact
that as a small dragonet adults would view the Marcus beast as just
food,and would prey on him.
The emphasis was to speed your way into adulthood,or remain as a more
able bodied and agile dragonet in order to survive till you could
find a suitable territory that could supply the nutrients needed to cause
your transformation into a bigger but less flexible adult
female or male and get on with the job of reproducing the species.