End date is still unknown, but a major change has been made to Pokémon GO. You'll now only find Fossil Pokémon in 7km eggs, not babies and other Pokémon.
In addition, Riolu is making his debut in the 10km eggs!
List of Fossil Pokémon available in 7km Eggs
Aerodactyl
Rock and Flying
Anorith
Rock and Bug
Archen
Rock and Flying
Cranidos
Rock
Kabuto
Rock and Water
Lileep
Rock and Grass
Omanyte
Rock and Water
Shieldon
Rock and Steel
Tirtouga
Water and Rock
It looks like Shadow Eggs will soon be available on Pokémon GO. Following the special 7km eggs recently included, these new little ones may just be linked to Team GO Rocket...