The fossilized footprints shown in the accompanying image, which are more than 365 milli...

The fossilized footprints shown in the accompanying image, which are more than 365 million years old, are part of a tetrapod trackway at Valentia Island, Ireland, and until recently, represented evidence of some of the oldest land-dwelling tetrapods. What evidence in this photo indicates the sediments were deposited in a wet environment, and how can you use the footprints to establish that the animal making them was a tetrapod?