In my fantasy world I have a species of reptilian humanoids.
- Their body mass, lifespan and overall intelligence is about the same as humans. This probably means similarly sized brains.
- They are NOT cold blooded. They have a human-like metabolism.
- The female gets internally fertilised and then lays an egg (rarely multiple eggs, like twins in humans).
- Their body plan is like bipedal dinosaurs. They walk bipedally on two legs, but with a horizontal spine like dinosaurs, NOT upright with a vertical spine like humans. (This probably influences the shape of the hips, which influences the maximal egg size.)
- They are highly social and live in tribes, towns or cities like humans.
- They are generally monogamous and mate for life.
- The atmosphere and available nutrients are similar to those on Earth.
I want to determine how long time their eggs take to hatch. There's two periods involved:
- The time from the moment of impregnation to the moment the egg is laid. I'm going to call this gestation, but there might be a more proper term for it.
- The time from the moment the egg is laid until it hatches. I believe this is called incubation.
Of course I can just pull numbers out of my rear end and say that gestation takes 3 months and incubation takes 6 months. But I'd like it to be more qualified than that.
Important factors include the sizes of the hatchling's brain, the egg itself and the female's birth canal. But I don't know about egg-laying animals enough to set them.
What are good arguments for why the gestation and incubation periods should be one thing and not another?
Preferably I would like the gestation period to be short. My reasoning is that the shorter the gestation period, the smaller the burden that automatically falls on the female, which can influence their gender roles.
Thanks in advance!
Here is pictured the Avisapiens saurotheos by C. M. Kosemen and Simon Roy. My lizard men don't look exactly like this, but similar.