The ankylosaurus dinosaurs had club-like tails for protection. But these were more than primitive weapons. The backs and tails of some ankylosaurs were protected by tough, lightweight armor so complicated it resembles the structure of a surfboard or bulletproof vest. 

Ankylosaurs grew up to 33 feet (10 meters) protracted. But they were vegetarians, and would have needed a good protective scheme. They lived in the late Cretaceous Period, around 70 million years ago -- equal time as T. rex. 

Torsten Scheyer of the University of Bonn studied a full set of ankylosaur chain mail. His findings, unrestricted yesterday, are a bit of a disclosure. Scientists had consideration the bony plates were made of a simple structure much like those of new crocodiles. 

Scheyer found two complex measures. In one, collagen fibers were interwoven in the bone calcium of the plates, forming mats that interweave from layer to layer. Within a mat, fibers were comparable, yet the fibers were vertical to those in the mats above and below. 

The armor was thus endowed with great strength in all directions, Scheyer said. 

The strong dino material functioned much like the fiberglass used in boat hulls and surfboards or the tough-but-light Kevlar of bulletproof vests, Scheyer told LiveScience. And as with fancy technological materials, the complex dinosaur plates were thinner and lighter than simpler and weaker versions on other ankylosaurs. 


The layering could attract large amounts of stress as the dinosaur swung its tail in self-defense. And providing it didn't roll over, it was well sheltered against a T. rex bite. 

The ankylosaurs were certainly the most heavily unbreakable beasts among all dinosaurs, Scheyer said.