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All of may not know this, but the Middle Jurassic La Boca Formation in Mexico boasts the most important Middle Jurassic tetrapod fauna in North America outside the US. Among the notable fossils found in the La Boca Formation are primitive mammals, sphenodonts, and even archosaurs (incl. the pterosaur "Dimorphodon" weintraubi and an unnamed mesoeucrocodylian). When compared to other Middle Jurassic faunas, it's interesting that the tritylodont Bocatherium is roughly the same age as the other two Middle Jurassic tritylodonts Bienotheroides and Stereognathus. As some of the components of the La Boca Formation vertebrate assemblage are related to their counterparts in China and Europe (e.g Bocatherium), future discoveries in the La Boca Formation could provide a new window into the biogeographic origin of the Morrison fauna, and it's not implausible that the Morrison fauna may have originated in Patagonia. Clark, James; Montellano, Marisol; Hopson, James A., Hernandez, Rene; & Fastovsky, David A. (1994). "An Early or Middle Jurassic tetrapod assemblage from the La Boca Formation, northeastern Mexico". In Fraser, N.C.; and Sues, H.-D. (Eds.). In The Shadow of the Dinosaurs: Early Mesozoic Tetrapods. Cambridge: Cambridge University Press. pp. 295–302.

While reading the SVP 2010 abstract book, I came upon an abstract by Ridgwell and Sereno (2010) discussing a non-stegosaurian, non-ankylosaurian, thyreophoran from the Jurassic Tiouaren Formation of Niger. As described by Ridgwell and Sereno, the Tiouaren thyreophoran possesses armor of various forms, including spikes, ankylosaur scutes and stegosaurian plates. Since the Tiouaren thyreophoran is more primitive than Eurypoda, how does this species shed light on the origins of stegosaur and ankylosaur armor? Ridgwell, N., and Sereno, P., 2010, A basal thyreophoran (Dinosauria, Ornithischia) from the Tiouraren Formation of Niger: In: 70th anniversary meeting of the Society of Vertebrate Paleontology, Program and Abstracts, p. 150a-151a.

Although Callovosaurus is now securely identified as the oldest dryosaurid, the confirmation of the dryosaurid classification of Callovosaurus by iguanodont guru Andy McDonald creates a ghost lineage for other groups of non-ankylopollexian iguanodonts, including the rhabdodonts (for which there are no Jurassic representatives yet). Since the Jurassic form Yandusaurus is recovered as a non-iguanodont ornithopod by Butler et. al. (2008), and Othnielosaurus, Agilisaurus, and Hexinlusaurus are recovered outside Cerapoda, is it possible that the lack of any Jurassic rhabdodontids is an artifact of sampling (considering that knowledge of Middle Jurassic ornithopods is still in its infancy)? The important thing to note is that Callovosaurus was fossilized in an island environment surrounded by ocean, and most other Middle Jurassic neornithischians are known from China and Argentina.