Monday, 17 December 2012

F is for Falcarius, which is not from Alberta

For our next post in the Albertan dinosaur alphabet, we come to the letter F. Unfortunately, there are no dinosaurs from Alberta that start with 'F', so we are going to talk about one from the US called Falcarius. Falcarius is a very strange dinosaur from the Early Cretaceous (about 130-125 million years ago) of Utah. Its name means 'sickle-cutter' in Latin, and describes the large claws on its long arms. Falcarius was a kind of theropod called a therizinosaur, which are very strange looking dinosaurs with long necks, wide bodies, and bipedal (walking on two legs) stance. This dinosaur is found from two bonebed locations in Utah, with possibly thousands of individuals being found here. 
Artists rendition of Falcarius by Michael Skrepnick, courtesy of University of Utah
Falcarius was much smaller than the later therizinosaurs at about 4 m long, 1.2 m tall, and weighing in at 100 kg. The bonebeds contain juveniles and adult individuals, with the smallest juvenile being just 0.5 m long. Therizinosaurs are known for being a group of herbivorous theropods, and Falcarius is no exception with its small, leaf-shaped teeth good for chewing vegetation. Although no feathers have been found on this dinosaur, closely related dinosaurs like Beipiaosaurus from China have well preserved feathers which suggests Falcarius did as well. 

This dinosaur is thought to be a "missing link" between the carnivorous theropods and the very strange therizinosaurids. These later therizinosaurids are often compared to large ground sloths with their huge torsos, likely roaming the ground for vegetation. Therizinosaurids also had large claws that reached up to a metre in length! 
Nothronychus, a derived therizinosaurid from the US. Image by Wikimedia user DinoGuy2
Since originally posting this, a new paper has come out which shows the structure of the brain of Falcarius and other therizinosaurs [1]. Remember back in September when we talked about how palaeontologists can use CT scans to better understand extinct animals? Well this is another great example of what CT scans can show us, and what they can tell us about the animal. They found that Falcarius and other therizinosaurs like Erlikosaurus and Nothronychus had well developed sensory abilities, especially with respect to smelling and hearing. A well developed sense of smell is normally found in carnivorous dinosaurs, while these animals were herbivorous or omnivorous. Since these herbivores had a great sense of smell, they suspect they were using it to track down plants with particularly smelly flowers or fruits. This is especially likely as they also found that therizinosaurs did not have a good sense of vision, so they needed to rely on smell and hearing to find food and avoid predators

Next week we'll be back to dinosaurs from Alberta with the letter 'G'. If you have any Albertan dinosaurs that start with 'G' that you'd like to hear about, let us know!

1 Lautenschlager, S, et al. 2012. The endocranial anatomy of Therizinosauria and its implications for sensory and cognitive function. PloS One 7: e52289.
Also check out Brian Switek's blog on this paper for more information here


  1. These are some of the coolest looking Dinos!

  2. They are definitely some bizarre dinosaurs. Arguably the are the most bizarre of all dinosaurs!