Gargoyleosaurus

a Gargoyleosaurus takes its stand against an Allosaurus 

Type Species: Gargoyleosaurus parkpinorum

Classification: Dinosauria – Ornithischia – Thyreophora – Ankylosauria – Nodosauridae

Time Period: Late Jurassic 

Location: North America

Diet: Herbivore   

Gargoyleosaurus is one of the earliest ankylosaurs, and it shared its habitat with another smaller ankylosaur named Mymoorapelta. Gargoyleosaurus had an eleven-inch skull and reached up to thirteen feet from its head to tail. As a nodosaur it lacked the tail club associated with many ankylosaurs. Gargoyleosaurus was a common low-browsing herbivore in the western United States, as three specimens have been discovered. Its armor – consisting of plates and conical spikes across its back and sides – would’ve served as a deterrent against contemporary predators such as Allosaurus. 

Mymoorapelta

a Mymoorapelta is flanked by a pair of Ceratosaurus

Type Species: Mymoorapelta maysi

Classification: Dinosauria – Ornithischia – Thyreophora – Ankylosauria – Nodosauridae 

Time Period: Late Jurassic 

Location: North America

Diet: Herbivore   

Mymoorapelta is one of the earliest ankylosaurs along with Gargoyleosaurus. Mymoorapelta was the first Jurassic ankylosaur to be discovered in North America, though scientists ponder its exact placement within Ankylosauria. Because it lacks a tail club, most scientists consider it to be a nodosaur (one of the ‘branches’ of Ankylosauria; these ankylosaurs lacked tail clubs). Some believe it to be a polacanthine ankylosaur, a ‘middle-ground’ between the clubbed ankylosaurs and the non-clubbed nodosaurs; others believe it is a basal ankylosaur that doesn’t fit into Ankylosauridae nor Nodosauridae. At only ten feet in length snout-to-tail, Mymoorapelta is the smallest herbivore known from the Morrison Formation. It was a low browser, feeding on ferns and cycads and other low-growing plants. Its armor would’ve given it decent protection against predators such as Allosaurus, but it may not have been an invulnerable deterrence, as predators were known to go after the plated and spiked stegosaurs in the same environment. Being so small and low to the ground, Mymoorapelta’s first line of defense may have been one of hiding among foliage to escape detection. 

a cast of well-preserved Mymoorapelta remains

Edmontonia

a club would be REALLY helpful right about now

Type Species: Edmontonia longiceps
Classification: Dinosauria-Ornithischia-Thyreophora-Ankylosauria-Nodosauridae
Time Period: late Cretaceous
Location: North America
Diet: Herbivore

Edmontonia's back was covered with an array of small, flat keeled (ridged) plates. Its neck and shoulders were plastered with larger keeled plates, and spines protruded forward from its shoulders. More spines ran along the sides of its body, tapering to nothing near its hips. This short, squat dinosaur no doubt used the spines as protection against predators and may have also used them in courtship displays or to battle with other males for potential mates. Edmontonia was a smaller dinosaur, but I'd still be willing to ride him: