Invictarx

Phylogeny: Dinosauria > Ornithischia > Genasauria > Thyreophora > Thyreophoroidea > Eurypoda > Ankylosauria > Euankylosauria > Nodosauridae

Overview: With its extensive armor and low-slung body, Invictarx is readily recognizable as having belonged to the Ankylosauria. Between the two major ankylosaur families, the Nodosauridae and Ankylosauridae, Invictarx usually finds itself referred to the former family. Nodosaurid genera like Glyptodontopelta may’ve been among its closest relatives. Members of this family tended to lack the clubbed tails of the ankylosaurs, but they often made up for it with large spines on their necks, shoulders or sides. As for Invictarx, we can’t be sure of the exact arrangement of its armor, but we do have some pieces of it in the form of osteoderms. Described as a genus in 2018, this armor was the inspiration for its generic name, meaning “invincible fortress” in Latin.

Invictarx is known from three or so specimens, represented by partial remains. In addition to the creature’s dermal armor, other known bones include ribs, vertebrae, and parts of the limbs. All of these fossils were found within the Menefee Formation of New Mexico. Invictarx would’ve lived alongside many other herbivorous dinosaurs, including hadrosaurs and ceratopsids. Theropods in the region included a dromaeosaur (possibly Saurornitholestes) and Dynamoterror – a member of the Tyrannosauridae and probably the region’s top land predator. Said region was a coastline, with numerous deltas, rivers, lagoons, and swamps. Invictarx also had to contend with gigantic river-dwelling predators like Deinosuchus (a crocodilian or close relative of true crocodilians).