Rhomaleopakhus

Rhomaleopakhus had one of the most robust (thick and strong) ulna bones of any known sauropod dinosaur.3

Its forearm bones were so strong that scientists think it evolved them separately from other sauropods, a process called convergent evolution.1

The only fossil found so far is a right forelimb, including the upper arm bone, two lower arm bones, a wrist bone, and a nearly complete hand.3

Rhomaleopakhus lived during the Late Jurassic period, about 152 to 143 million years ago.2

Its fossils were originally thought to belong to another dinosaur called Hudiesaurus, but scientists later realized they were from a different animal.1

Rhomaleopakhus belonged to a group of long-necked sauropods called Mamenchisauridae, which were common in Asia during the Jurassic.12