Now this is where it gets a little finicky. You have two simultaneous effects, which go on the chain. Normally turn player is chain 1 and opponent is chain 2, so when resoliving backwards
Newdoria will destroy before Pyramid will special summon.
However,
Pyramid Turtle's effect is optional (the whole you "can" special summon a Zombie type). That being said. I believe technically speaking the turn player has the choice whether or not to resolve the effect immediately. If not,
Newdoria becomes chain link 1 and Pyramid becomes chain link 2, so Pyramid would summon and then
Newdoria would destroy.
Why does this matter? Well If Turtle is the only monster on the turn player's side of the field, they may elect to make their effect second on the chain. That way they can summon VLord and force
Newdoria to wipe it out.
I'm a little iffy on the full mechanics of the optional vs. mandatory effects, so somebody else is more than welcome to step in and help validate this.
EDIT: I do believe this is the case. Here's the ruling on Pyramid vs.
UFOroid.
[Re: UFOroid ] If "UFOroid" attacks an Attack Position "Pyramid Turtle", first the turn player decides whether to activate the effect of "UFOroid" or not, and if he does, it will be Chain Link 1. If he doesn't, the opponent has a chance to activate "Pyramid Turtle's" effect and be Chain Link 1. If he does, it is too late for the turn player to decide to activate "UFOroid's" effect.
Notice they have the same type text in their effects. So actually, if turn player decides to bypass Pyramid's special summoning effect, then it has now missed the timing and can't go on chain link 2.