Hi,
I can't specifically say I've seen a turtle with a load on it's back but you are a bit vague about what you are asking about. Maybe this will help you. As you know, a turtle is a high priority treasure sign. A turtle indicates you are very close to the treasure. A turtle with no legs means you are extremely close.
I apologize for the low quality on this picture. It was chalked in a hurry which is something we should never do. At any rate, maybe this will be of benefit to you. If you will look at the bottom of the picture, you will see a burrow with no legs. An animal with legs or a bird with wings usually indicates you have to travel but no legs means the treasure is right there. It is hard to tell the way this was chalked but it has a load on its back. One ear is drawn forward as a pointer. It would make you think it is pointing towards the treasure. Look at the letters at the top "JAS" with 3 oval dots in a triangle shape. One of the meanings for this is to look in the Holy Bible at James 3:3. This will give you the true direction that the horse is trying to convey. Get your compass and see how it points and then reverse that direction. Without seeing your turtle, it is hard to help however, the tail is generally the direction to go although not always.
Good luck,
Boattow