Dinosaur's 50-Foot Neck Confirmed as Accurate.

Researchers estimate that the neck of Mamenchisaurus, a sauropod that roamed China during the late Jurassic period, stretched to nearly 50 feet, making it the longest estimated neck of any sauropod species and possibly the longest neck on any animal ever observed. The estimate was made by comparing Mamenchisaurus to its close relative, Xinjiangtitan, whose entire vertebral column was unearthed. The study also found that the sauropod's neck was reinforced with cervical ribs and had hollow vertebrae filled with air pockets to decrease its weight.