Barbary Lions are not 4m long. They're definitely heavier than any other lion species though.
Baiji are extinct or at least functionally extinct (isolated individuals of advanced age have been seen).
Steller's Sea Cows are 100% extinct and were frighteningly large.
Who's gonna be the big boss of the extinct mammals? The Tasmanian Tiger? The Dire Wolf? Sabre-toothed Cat? One of the two extinct Japanese wolves? The Japanese river otter?
Speaking of big bosses, I wonder when my favorite biggest of the big cats, the Amur Tiger is gonna make his/her appearance. They're wicked smart, too. Capable of holding grudges towards specific humans, as evidenced by Yuri Trush in his hunt for a man-eating tiger who staked out a man's house for 12-48 hours before getting the chance to kill him, rip him apart, and finally eat him.