Preterm birth
James Elgin Gill (born on 20 May 1987 in Ottawa, Ontario, Canada) was the earliest premature baby in the world, until that record was broken in 2014. He was 128 days premature (21 weeks and 5 days' gestation) and weighed . He survived.
Black lion tamarin
Most infants deaths occur within the first two weeks of birth, with newborns of first-time mothers having the lowest survival rates. The number of tamarins that survive to adulthood in the wild is 10% higher than those in captivity.