In the 5th Edition Monster Manual, it states the following under the Dracolich Phylacteries section:
If a dracolich's physical form is ever destroyed, its spirit returns to the gem as long as the two are on the same plane. If the gem comes into contact with another dragon's corpse, the dracolich's spirit can take possession of that corpse to become a new dracolich.
My question is, does the dracolich assume the new corpse's type? For example, if an Ancient Black Dracolich is destroyed, and then its gem comes into contact with an Adult Silver Dragon's corpse, would it reform as its original self (Ancient Black Dracolich), or become the new corpse type (Adult Silver Dracolich)
If the former, would any dragon corpse do? As the restrictions to become a dracolich require ancient or adult, but the text for consuming a corpse just specifies "another dragon's corpse." (Seems silly that an Ancient dracolich could regain full powers from coming in contact with a wyrmling, but that popped into my head when writing this question.)