Stegomosuchus longipes, the terrestrial croc relative of Massachusetts

If you're the kind of person who reads this blog regularly, you're probably also the kind of person who's got at least one rock laying around. Maybe you've got dozens. Maybe you've got too many. Who am I to judge? The point is you've got rocks. Odds are, though, there isn't a potential type specimen in your yard.

The first fossils described from Dinosaur National Monument

The first fossils described from Dinosaur National Monument (to the best of my knowledge) were not dinosaurian. They weren't vertebrate. They weren't from the Morrison Formation. They weren't from the Jurassic, or even the Mesozoic. You may not realize it, but the monument has a geologic record extending from the Neoproterozoic to the Quaternary (see for example Untermann and Untermann 1954, Gregson et al. 2010, or Santuci and Kirkland 2010). For this bit of history, we're also going back in geologic time.

Echo Park, at the confluence of the Green and Yampa rivers (NPS/Jacob W. Frank). Why this landmark? Read on!

Rhabdodontidae

French geologist Philippe Matheron named Rhabdodon priscus in 1869, making it among the oldest dinosaur names still in use. In terms of public interest, Rhabdodon and its close relatives have definitely been late bloomers. From 1869 through the 1990s, we've had a few papers, but the only person who seems to have put much energy into rhabdodontids during that time frame was the inimitable Baron Franz Nopcsa. The fortunes of the group have picked up in the past few decades; several new species have been described since 2000, old species have been reevaluated, and there was even an appearance in a segment of a TV documentary special. (Of course, there were the usual drama-related inaccuracies, and the rhabdodonts had to go in disguise as "dwarf Iguanodon", but at least they were there.) The latest news is a reevaluation of rhabdodontid paleobiology that makes them into something more than stock small ornithopods.