Balaur

Everyone's talking about and doing pictures of this new maniraptor, so I may as well join. (Blah, Haplocheirus sollers is more significant!*)

Either way, Balaur bondoc is a newly described dromaeosaurid (robust "raptor") from Romania, which was part of an island archipelago in the Cretaceous. Interesting things happen to creatures that happen to reach islands, and Balaur bondoc is no exception. Its first toe was very large and reached the ground, whereas in typical theropods ("meat-eating" dinosaurs) the first toe is small and high on the foot. Most deinonychosaurs ("raptors") have a retractable second toe, and the describers of Balaur bondoc interpret the first toe as a second retractable digit. Its legs and pelvis were very stoutly built, suggesting it was a rather thickset animal. If it was a predator, it certainly would've fulfilled the popular image of dromaeosaurids as powerful hunters that grappled with larger prey. This was one dromaeosaurid that could've conceivably attacked the hadrosaurs and sauropods in its habitat. (To be fair, these herbivores were smaller than their mainland counterparts, but they were still the size of horses, quite a bit larger than Balaur bondoc.)

However, paleontologist Andrea Cau of the Theropoda blog has come up with an alternative hypothesis, known as the dodo raptor hypothesis. The big first toe of Balaur bondoc may have been used for supporting its weight instead of a weapon. (We don't actually know if the first toe really is retractable. Although the fossilized foot preserves it that way, a dead animal can bend in ways a live animal can't. Dead Microraptor zhaoianus can sprawl their hind legs and dead Archaeopteryx lithographica can reverse their first toes, for example.) The strong pelvis and hind limbs may have been to hold longer intestines for digesting vegetation. Also interesting is that Balaur bondoc has only two claws on each wing, unlike other deinonychosaurs, which have three, suggesting a reduced function in predation. It may also have had a shorter tail than other deinonychosaurs. In other words, Balaur bondoc may have been an omnivorous or herbivorous dromaeosaurid, similar in form to therizinosaurs (ground sloth dinosaurs) and flightless columbiforms! (If so, this would make it almost as important as Haplocheirus sollers. Almost. Not quite.)

Since there is no skull material for Balaur bondoc so far, we can't be sure if either of these hypotheses are correct, but it makes for good discussion.

*There are only about five Haplocheirus sollers on DeviantArt. It's unfair!