Parankylosauria

Parankylosauria is a group of armored thyreophoran dinosaurs known from the Cretaceous of South America, Antarctica, and Australia. Most analyses place parankylosaurs as a member of the Ankylosauria, in which case the group would have split from other ankylosaurs during the mid-Jurassic period, despite this being unpreserved in the fossil record. Another analysis has proposed that parankylosaurs are instead a distinct lineage of non-ankylosaurian armored dinosaurs with more ancestral anatomy. Several parankylosaurs are characterized by a distinctive frond-like tail weapon (called a 'macuahuitl'), made of several fused osteoderms projecting outward.

==History of research== thumb|left|Fossils remains of the parankylosaur Antarctopelta; early discoveries of ankylosaurs in the Southern continents were often fragmentary. During the Mesozoic era, the southern continents (South America, Antarctica, Australia, and Africa in addition to India and Zealandia) were unified into a supercontinent known as Gondwana. This was in contrast to the supercontinent of Laurasia in the Northern Hemisphere, with both originating from the breakup of Pangaea. Gondwana itself gradually split apart over the course of the Jurassic and Cretaceous eras. Ankylosaurian dinosaurs from Laurasia have historically been far more extensively recorded and studied. Reports of the group in Gondwana date back to 1904, with a specimen from Australia and include referrals of Loricosaurus, Lametasaurus, and Brachypodosaurus to group among assorted fragmentary material. Much of this material including would later be shown to be misidentified and not belonging to ankylosaurs, including the named genera. The first definitive ankylosaur to be recognized from Gondwana was discovered in Australia in 1964 and later named in 1980 as Minmi paravertebra.