Been thinking too much about my world's dragon rider culture and their big sassy pterodactyls pretending to be dragons, called Wyverns or Twintail dragons to distinguish them from the many smaller species of dragon adjacent creatures that inhabit their world. They are largely considered the closest to mythical dragons that many attempted to create at the dawn of magic, as they are large enough to bear riders and can (with the help of those riders) breath something approximating fire.
However, since they're relatively fragile owing to their hollow bones and no real natural armor they are mostly retained and supported by local infrastructure for their message carrying and dignitary transport capabilites over their utility in warfare- though it's not unheard of.
They're also quite sensitive creatures, not quite fully sapient but certainly more intelligent than the average beast, and if they don't feel inclined to commit to a job there is only so much even their riders can do to direct them given the size difference. And the teeth.
I've put way too much thought into designing a saddle that could be used in flight and on the ground, and on the back of a creature so much larger than it's rider. Much less one that's also usable at various angles in between, depending on the individual dragon's preferences for walking. Some dragons are open to their rider's inputs than others, but most have a preferred stance and will not be swayed from it when on the ground and seems to have a lot to do with the dragon's personality and social hierarchy in addition to simple physical variation between individual dragons.
These guys are born from eggs and are about cat sized on hatching, with some rider enclaves raising them in creches but most immediately give over their raising to their future rider. Usually a teen to young adult at the time, since the average lifespan of a dragon is about 40 years, this is a lifetime commitment for both dragon and rider. They grow to about mastiff sized within their first year, and then horse sized by 3 or 4 years old and begin their flight training with the introduction of harness and the permanent holes for a saddle are pierced in the wings behind the shoulders. A difficult to define bond is born between the dragon and their rider as they grow together and cemented by flying together as adults when the dragon is ~5 years old and riderless dragons will typically go mad or feral rather than obey anyone but their original rider.
While their growth plateaus at about 15-20 and the average lifespan is only 40 years, up to 60 years is not uncommon with tales told of oldsters getting up to a legendary 100 years! But since they never truly stop growing after about 50 most cannot fly anymore and slow elderly metabolisms mean they spend their days sunbathing and sleeping through twilight years under the attention of loving elderly keepers.
