Gastonia

About Gastonia

Characteristics: A Walking Fortress and Unique Armament

Gastonia was a heavily armored ankylosaur (armored dinosaur) that lived on the North American continent during the Early Cretaceous period of the Mesozoic era (about 139 to 125.77 million years ago). It is estimated to have reached a length of about 4.5 to 6 meters and a weight of about 1.9 tons. It had a broad, flat body and thick, powerful short limbs.

Its entire body was densely covered with bone-like skin (osteoderms) that evolved like armor. It also had armor on its neck, and large, flat triangular spikes curved backward lined the sides of its shoulders and body.

The upper part of the hips was covered by a massive monolithic shield made of several fused bone plates for defense.

Role of Spikes: Anti-Predator Defense and Intraspecific Combat

The apex predator Utahraptor, which had powerful claws, lived in the environment where Gastonia lived. Gastonia developed strong armor on its neck, back, and hips to perform a "passive" defense against predators trying to jump on it.

Furthermore, as an "active" defense, it is thought to have performed a deadly counterattack by swinging its tail violently like a whip, using the sharp triangular spikes lining the sides of its tail to inflict deep cuts on enemies (it did not have a "tail club" like Ankylosaurus).

Also, Gastonia's spikes and armor seem to have been used not only to protect themselves from predators but also for communication between members of the same species. The giant spikes protruding from the back would have been a visual appeal (display) to rivals, and it has been pointed out that males may have determined dominance by "headbutting" each other. Evidence has also been found that the skull structure acted as a cushion to absorb the impact of headbutting.

Ecology: Diet and Sociality

Gastonia was a herbivorous dinosaur that ate low-growing plants. It had a toothless "beak" at the tip of its mouth, and 15 to 16 small teeth lined up in a straight line on its upper jaw. From this structure, it is thought that they efficiently "clipped" plants rather than grinding them finely.

Interestingly, recent analysis of microscopic scratches (microwear) on their teeth suggests that juveniles and adults may have preferred different plants. Small juveniles ate highly nutritious parts like fruits and soft shoots, while adults, who could ferment food in their massive intestines, seem to have eaten highly fibrous plants like ferns.

In the past, ankylosaurs were thought to be "animals that spent most of their lives alone" due to their heavy armor and slow movement. However, Gastonia fossils are often found concentrated in large numbers at a single excavation site, strongly suggesting that they lived in herds.

Discovery and Paper Publication

In 1989, fossils of a new ankylosaur were discovered by paleoartist Robert Gaston in Grand County, Utah, USA (Cedar Mountain Formation). These fossils were excavated from the same quarry as Utahraptor, a carnivorous dinosaur that lived during the same period.

Later, in 1998, it was described by American paleontologist James Kirkland as a new genus and species, "Gastonia burgei". The genus name "Gastonia" was given in honor of its discoverer, Robert Gaston.

In 2016, a second species, Gastonia lorriemcwhinneyae, discovered in a slightly different layer of the same Cedar Mountain Formation, was also described.

Gastonia Stamp and Fossil Gallery