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Longest gestation period (mammal)

Longest gestation period (mammal)
Who
Asian elephant, Elephas maximus
What
18-22 month(s)
Where
United Kingdom
When
N/A

The Asian elephant (Elephas maximus) has the longest-known gestation period of any mammal with a pregnancy duration of between 18 and 22 months - the higher limit almost two and a half times the length of human gestation.

In July 2023, a paper published in the journal Royal Society Open Science posited that the baleen whale (Balaena mysticetus) may take this crown, with a potential gestation of 23.6 ± 1.50 months, but farther research is needed before this can be fully confirmed.