Mamenchisaurus lived about 160 million years ago in what’s now China. From shoulder to head-tip, its neck stretched about 45 feet - longer than a school bus, longer than two giraffe necks stacked end to end, longer than anything else’s neck ever, as far as scientists know.
The neck had 19 separate vertebrae (humans have just 7), and each one was reinforced with bony struts and full of air sacs. Even so, it must have been quite a feat of balance: scientists are still arguing about whether Mamenchisaurus held its neck out straight like a horizontal crane, or lifted it high to graze treetops.
What it gained from that giant neck was a buffet that no other animal could touch - and the ability to stand in one spot while sweeping miles of forest with its mouth.
