“Qijianglong is a cool animal. If you imagine a big animal that is half-neck, you can see that evolution can do quite extraordinary things,” said Miyashita.
Mamenchisaurids are only found in Asia, he added, but the discovery reveals that there could be as many differences among mamenchisaurids as there are between long-necked dinosaurs from different continents.
“Qijianglong shows that long-necked dinosaurs diversified in unique ways in Asia during Jurassic times—something very special was going on in that continent,” said Miyashita. “Nowhere else we can find dinosaurs with longer necks than those in China. The new dinosaur tells us that these extreme species thrived in isolation from the rest of the world.”
Miyashita believes that mamenchisaurids evolved into many different forms when other long-necked dinosaurs went extinct in Asia. “It is still a mystery why mamenchisaurids did not migrate to other continents,” he said. It’s possible they were once isolated as a result of a large barrier such as a sea, and lost in competition with invading species when a land connection reappeared later.
The Qijianglong skeleton is now housed in a local museum in Qijiang. “China is home to the ancient myths of dragons,” said Miyashita, “I wonder if the ancient Chinese stumbled upon a skeleton of a long-necked dinosaur like Qijianglong and pictured that mythical creature.”