A new long-necked ‘sauropod-mimic’ stegosaur and the evolution of the plated dinosaurs. 2009. O. Mateus, et al.Proc. Royal. Soc. B. published on-line Feb. 25, 2009.
Abstract: Stegosaurian dinosaurs have a quadrupedal stance, short forelimbs, short necks, and are generally considered to be low browsers. A new stegosaur, Miragaia longicollum gen. et sp. nov., from the Late Jurassic of Portugal, has a neck comprising at least 17 cervical vertebrae. This is eight additional cervical vertebrae when compared with the ancestral condition seen in basal ornithischians such as Scutellosaurus. Miragaia has a higher cervical count than most of the iconically long-necked sauropod dinosaurs. Long neck length has been achieved by ‘cervicalization’ of anterior dorsal vertebrae and probable lengthening of centra.
Miragaia longicollum is based upon a partial articulated skeleton, and includes the only known cranial remains from any European stegosaur.
A well-resolved phylogeny supports a new clade that unites Miragaia and Dacentrurus as the sister group to Stegosaurus; this new topology challenges the common view of Dacentrurus as a basal stegosaur.