Balaur: Prehistoric Beast of the Week

It's getting closer to Halloween and I don't know about you but it seems I can't flick on the TV without seeing at least one horror movie.  Werewolves were always my favorite horror monster and there are certainly no shortage of those in pop culture.  There are also a lot of undead, especially vampires.  Did you know that Romania, the country where a lot of the stories for these famous monsters originally came from, was also home to a completely different (but equally intimidating) kind of "monster" millions of years ago?  Yup, prehistoric dinosaurs used to live there.  One of the most interesting was Balaur bondoc!

Balaur bondoc life reconstruction by Christopher DiPiazza.  Here it is depicted exhibiting either predatory behavior or possibly play behavior on an unlucky baby crocodilian.

First described in 2010, Balaur was a five-foot long theropod that lived during the late Cretaceous roughly 70 million years ago.  The most striking feature about this dinosaur is the fact that the first claw on each of its feet, which is normally very short in most theropods, was actually very large.  It is similar to the long, sickle-shaped claws that are the second toes on dromaeosaurids, like Velociraptor and Deinonychus.  In addition to this first foot claw, Balaur's second digit toe also had a long, retractable talon...so it had two giant sickle claws on each foot...neat!  When alive Balaur would have been covered in feathers.

The exact identity of Balaur has undergone a few changes over recent years.  At first it was believed by most to be a predatory dromaeosaurid, like Deinonychus, or Velociraptor, due its foot claws.  However, more recently it has been suggested that Balaur was actually a kind of large, flightless bird, more closely related to dinosaurs like Archaeopteryx.  Furthermore, it has also been suggested that Balaur was either an herbivore or omnivore, hunting small animals occasionally, like modern galliform birds (chickens, pheasants, turkeys...) do.  This is due to it only having two fingers instead of the normal three on each hand, a much wider and stockier body, and the fact that the bones that have been discovered resemble those of other, more completely known prehistoric birds that are known to have been either herbivores or omnivores, when inspected closely.  It is difficult to tell exactly what Balaur was eating because no part of its skull, including the teeth, have ever been found, however. As for the function of the two giant claws on each foot, some speculate it may have been to help Balaur support itself on the ground, since it was pretty stocky for its size, or perhaps it was a light climber, like many modern ground birds are, and used them to help perch on low branches.  Lastly, if Balaur was actually a meat-eater at least some of the time, the claws would have definitely been useful for pinning small prey down to be eaten.

Sketches of the foot of Deinonychus compared to that of Balaur.

Since Balaur was was so stocky and robust compared to its more lightly-built relatives, It likely would have relied more on strength than speed to survive.  Its full name, Balaur bondoc, actually translates to "stocky dragon".  Some have compared Balaur to the more recent Dodo Bird, having evolved to be slower and heavier in response to being genetically isolated, and perhaps having fewer predators given its habitat.  This is because Romania was actually an island back during the Cretaceous when the sea level was much higher.  Whenever you have animals that live on islands, they evolve differently because they are living in a unique environment.  For modern examples check out all the unique creatures living today in places like the Galapagos Islands or New Zealand.  Nowhere else in the world will you find Marine Iguanas, flightless cormorants, Kakapos, or Kiwis!  The animals Balaur co-exitsted with were also unique, including miniature or "dwarf" forms sauropods and a hadrosaurs (two kinds of dinosaurs which are known for having been very large everywhere else on the globe).

Fossil remains of Balaur.  You can see the double "killer claws" in the lower right corner of the photo.

That's all for this week!  As always comment below or on our facebook page!  Have a creature you want painted and reviewed?  Just let me know and I will make it happen!  Tune in next weekend for another dinosaur that has a connection to Halloween!  Can you guess how?

References

Brusatte, S. L. et al. (2013). "The Osteology of Balaur bondoc, an Island-Dwelling Dromaeosaurid (Dinosauria: Theropoda) from the Late Cretaceous of Romania" Bulletin of the American Museum of Natural History 374: 1-100. doi:10.1206/798.1

Cau, Andrea, Tom Brougham, and Darren Naish. "The Phylogenetic Affinities of the Bizarre Late Cretaceous Romanian Theropod Balaur Bondoc (Dinosauria, Maniraptora): Dromaeosaurid or Flightless Bird?" PeerJ 3 (2015): n. pag. Web.

Godefroit, Pascal; Cau, Andrea; Hu, Dong-Yu; Escuillié, François; Wu, Wenhao; Dyke, Gareth (2013). "A Jurassic avialan dinosaur from China resolves the early phylogenetic history of birds". Nature. in press. doi:10.1038/nature12168.

Z., Csiki; Vremir, M.; Brusatte, S. L.; and Norell, M. A. (2010). "An aberrant island-dwelling theropod dinosaur from the Late Cretaceous of Romania". Proceedings of the National Academy of Sciences of the United States of America 107 (35): 15357–15361. doi:10.1073/pnas.1006970107. PMC 2932599. PMID 20805514.