ok this ones got me totally stumped. I was cleaning turtle tank(150 gallon galvanize trof) I found one egg hidden under a pile of rocks completely submersed and always has been. I have several different turtles in this tank of diffenet sizes. This egg is elongated and about 2 inches long,rubbery . I swear looks like snake egg. I found three empty shells in the bottom of tank . The water level is always 4 inches lower then the tank. All contained in a six ft. privacy fence. No other water within 2 miles. Any theories would be greatly appreciated.

