Micropachycephalosaurus is a mouthful, so we’re just gonna call it a Micro. Micros were extremely small herbivores that, as you can see, have the longest names of any dinosaur. Micropachycephalosaurus means “small thick-headed lizard” in Greek, and when discovered were thought to be pachycephalosaurs, a group of ornithopods whose heads possessed thick bony domes that were used as a means of fighting.
Micros lived up to their name in being extremely small. An adult would have been only 3 feet long and tall and weighed at most 10 pounds. They were even smaller than Compsognathus! While it was first thought to be a pachycephalosaur, new studies haven’t found any evidence for this theory. In fact, paleontologists now think that they were very basal and primitive ceratopsians.
This is very surprising because unlike other basal ceratopsians that lived at the start of the Cretaceous, Micros lived alongside advanced and definitely not basal ceratopsians such as our own Triceratops. Most of Micro’s direct cousins went extinct a while back, so it is unexpected that Micro didn’t evolve as much.
Anay Ganesh 