Minmi is a genus of small herbivorous ankylosaurian dinosaur that lived during the early Cretaceous Period of Australia, about 119 to 113 million years ago.
Minmi was a small herbivorous quadrupedal armoured ankylosaurian. In 2010, Gregory S. Paul estimated its length at three metres, its weight at three hundred kilogrammes. For an ankylosaurian, Minmi had long limbs, perhaps used to quickly search cover under brushes when threatened by large predators which might have been able to flip the small animal on its back.
Unlike other ankylosaurians, Minmi had horizontally oriented plates of bones that ran along the sides of its vertebrae, hence its specific name, paravertebra. Molnar in 1980 acknowledged that these were ossified tendons, but denied that they were homologous to the ossified tendons of other Ornithischia and claimed that they resembled the pathological tendon aponeurosis of modern crocodiles. Victoria Megan Arbour in 2014 deemed this unlikely and could find only one autapomorphy in the holotype: the high vertical extent of the musculus articulospinalis tendon ossification at its outer front end, wrapping itself around the side process of the vertebra. In 2015, Arbour and Philip Currie concluded that even this was not unique, which would mean the holotype had no diagnostic features and Minmi would be a nomen dubium. However, the 2015 description of Kunbarrasaurus announced that new distinguishing traits of Minmi had been discovered and that it should be considered a valid taxon.
A study of preserved gut contents (cololites) in Minmi shows that it ate the seeds and fruiting bodies of flowering plants as well as ferns and other soft-leaved plants. This is the first such study in either ankylosaurs or stegosaurs, and the best evidence yet for the diet of herbivorous dinosaurs. It suggests a mainly herbivorous diet for Minmi (one theory proposes that ankylosaurs may have been partly insectivorous). The plant material found in Minmi’s abdominal region was finely diced, and Minmi may have cut its food with its serrated cheek teeth after nipping the vegetation off with its beak. The food would then be within the mouth (possibly helped by development of fleshy cheeks). Gastroliths were absent, suggesting that Minmi’s teeth were quite efficient at processing food.