The Year of the Ceratopsian Ankylosaurs

Life restoration of an advanced stegosaur- I mean an ankylosaur (Ankylosaurus magniventris) by Emily Willoughby,  CC-BY-SA.

When digging into the history of North American fossil interpretation for the eventual next edition of my Beasts of Antiquity series, one thing that I found a bit weird was the constant reference to ankylosaurids and nodosaurids as types of stegosaurs. To a modern reader, this seems off. After all, the group of armored dinosaurs, Thyreophora ("shield bearers"), is divided into two major groups: Ankylosauria and Stegosauria, each with a few well supported subgroups. It makes sense that these close relatives might once have been classified together, and stegosaurs were discovered first, lending them priority of name. But what changed? Neither ankylosaurs nor stegosaurs are particularly large groups (especially the stegosaurs), and it seems odd that 20th century taxonomists would want to raise a group as small as the modern idea of Stegosauria to the level of "suborder".  Why were ankylosaurs eventually spun off, leaving the more primitive stegosaurs behind? I decided to do a little digging to find out.

Miragaia: So long, stegosaur

Here's another new species for you gosshounds: Miragaira longicollum, or "long-neck from Miragaia village, Portugal."

This is a new stegosaur with a twist--look at that neck!

Photo credit by Dr Octavio Mateus.

As Tom Holtz pointed out on the DML, first we had Brachytrachelopan, the stegosaur-like short-necked sauropod, and now Miragaia, the long-necked stegosaur. Then he cryptically adds that there's another new dinosaur coming out that wants to belong to a different suborder... Could it be a long-necked theropod? Not that we don't have any, but maybe a long-necked 'carnosaur'? Or a short-necked ornithomimid? Or a flying ornithopod? Stay tuned to find out!

As the Everything Dinosaur blog is speculating, Miragaia might have implications for the old debate (and SVP poster joke) about bipedal stegosaurs. Long necks usually mean high browsing, dontcha know. Well, the Goss would point to diplodocid sauropods (which are now known to have had straight necks held close to the ground for low browsing over a wide area) as possibly a better example. But given the long back legs of stegosaurs and very robust forelimbs of Miragaia (maybe for doing "push-ups" into a bipedal or tripodal stance?), and the fact that the neck is pretty high from the ground, so unless it was wading shoulder-deep in ferns... Well, who knows? More opinions likely to come!