One sign of a newly hatched turtle is the egg tooth used to cut through the shell of the egg at hatching. The tooth is that white bump just below the nostrils. The egg tooth will disappear a few weeks after hatching.
Another sign of the hatchling is the unhealed area on the lower shell where the yolk was attached. This area will also quickly disappear. This youngster is a perfect replica of what it will look like 20 pounds from now.
Female Snapping Turtles will travel long distances from water to lay their clutch of eggs. This means that the little hatchlings have a long way to travel before finding a suitable home. I suppose this method helps spread the turtle population over a larger area and reduces the chances that these babies will return to compete with their parent for living space. The nearest permanent water body that would contain Snapping Turtles is 900 feet from the water garden, so between mother and baby, at least that distance had to be traveled.