I don't think my dogs killed it, they didn't even know he was in there, never showed any interest. BUT, if he was walking in the yard, he was fair game to them. I suspect the dead turtle was more likely killed on the road and one of them drug it into the yard. I really don't think they would have killed him, but I may be wrong. Bark excessively at it, yes, kill it, probably not.
Oh, yippee!!! I just looked at the picture I took when I found Aris, and it was NOT him. Aris was maybe at most half length of my palm, and this dead turtle's bottom shell was almost the length of my hand, so the top shell would have been even larger. Woohoo! At least it wasn't Aris. Maybe he's in there, just hiding because of the new arrival of the larger turtle. And, I'm pretty sure the smaller one is still in there, as that is what was pecking at the lily bloom. Sooo funny, bloom kept bouncing and getting hit, finally walked where I could see the reason, and saw the turtle, about the same time it saw me and ducked down. Aris would not have ducked so quickly, and it was MUCH smaller than the larger one. Who knows how many turtles are in that pond. Don't see any in the koi pond ... yet!
Now I wonder with the larger size, although it's not huge by any means, of the new turtle, if I have to worry about it biting the fold in the bottom of that pond and causing a hole. I think they eat plants and algae and bugs, not sure about fish but suspect they will eat anything they can catch, although they are not very fast, and not as crafty as snappers. So, if anyone thinks it could bit through the liner folds, then I will remove it and take it back to the farm pond, where it came from.