While it is the biggest known land animal in the modern days, elephant is also the land mammal with longest pregnancy period. The following is the list of the top ten longest pregnancies (land mammal):-
1.
Elephant
21-22 months
Maximum birth weight: 120kg
Life span: Up to 80 years
2.
Rhinoceros
15-18 months
Maximum birth weight: 65kg
Life span: Up to 50 years
3.
Giraffe
15 months
Maximum birth weight: 75kg
Life span: Up to 25 years
4.
Camel
13-14 months
Maximum birth weight: 50kg
Life span: Up to 50 years
5.
Tapir
13 months
Maximum birth weight: 10kg
Life span: Up to 30 years
6.
Donkey
12 months
Maximum birth weight: 25kg
Life span: Up to 50 years
7.
Llama
11-12 months
Maximum birth weight: 14kg
Life span: Up to 25 years
8.
Horse
11 months
Maximum birth weight: 55kg
Life span: Up to 60 years
9.
Cow
9-10 months
Maximum birth weight: 40kg
Life span: Up to 20 years
10.
Human
9 months
Maximum birth weight: 7kg
Life span: Up to 130 years
Source:
Sunday Edition, Daily Express 5/5/13