Imagine a walking living tank that is covered in armor from its nose to the tip of its tail. Gastonia is an ankylosaurian dinosaur from the Early Cretaceous of North America, around 125 million years ago. Discovered in a bonebed of the lower Cedar Mountain Formation in Grand County, Utah. It was discovered in 1989, but not until recently have scientists been able to describe how devastating and successful this animal actually was. It could reach lengths other 20 feet long and weighed up to 4,200 pounds!
We have all heard of the larger Ankylosaur with its large club at the end of its tail. Its popularity has grown with movies like Jurassic Park and Jurassic World. Gastonia was a very similar dinosaur but with a very different and more sinister weapon. Gastonia had large 2 foot spikes that came out at the shoulders and back and continued down its sides and tapered off at the tail. Each one of these one of these spikes, like the rest of its armor, would have been covered with Keratin, the same material that makes up our hair and fingernails. This means that the spikes could have reached a length of 3 feet and would come to an extremely sharp and nasty point! Its entire head and back would have been covered with keratin and spikes and would have made this animal almost impossible to attack from above.
Here is the nasty part. Along the length of its tail was a series of curved flattened spikes that almost make the shape of a sharks tooth. What is remarkable about these spikes is that they are staggered. Meaning that are not in a perfectly straight line down the tail. When this animal swings its tail the spikes would overlap like a set of prehistoric deadly scissors! So any animal that unfortunately finds itself in the way of Gastonia's swinging and curving tail could very well have been SLICED OPEN! The spikes would have closed on another animals flesh and cut right through it with speed and force. We are talking about 8 inch scissors wrapping around and cutting though flesh with ease.
This defensive adaptation was much needed because living at the same time as Gastonia with one of the most deadliest predators ever to exist on the planet. Utahraptor! A 6.5 foot tall theropod with a vast variety of weapons. Knife like teeth, 5 inch slashing claws on its hands, unmatched speed for the time, 8 inch killing claws on the inner toe on both feet and most deadly of all, it was one of the smartest dinosaurs/predators ever! Gastonia would have had to fend off killers like Utahraptor more often then it would have liked. AND! it would have sometimes have had to deal with more than one since raptors hunt in packs.
As long as Gastonia could keep its body low to the ground so as not to expose its vulnerable soft underside, it would have been an extremely difficult prey item for these predators. And if it could time it perfectly, it could have sliced open and killed a raptor with one swing of its tail. I would venture to guess making the rest of the raptor pack think twice about its attack. Especially on a healthy adult Gastonia.
This is one of those animals that would have most likely have just been lumbering about, minding its own business and conserving energy until some brave predator or threat decided to take on the challenge. Needless to stay, this was one animal that would have been best to just leave alone.