Ola,
I mean by "
Pterodroma [mollis] sp" any species belonging to the
Pterodroma mollis superspecies, that includes (according to IOC):
Soft-plumaged Petrel (Pterodroma mollis)
Zino's Petrel (Pterodroma madeira)
Fea's Petrel(Pterodroma feae)
Desertas Petrel (Pterodroma deserta)
http://www.worldbirdnames.org/n-penguins.html
I agree of course than mollis is the least likely!