page_title: Falcarius
section_title: Classification
hierarchical_section_title: Falcarius / Classification
caption_attribution_description: Falcarius utahensis, pelvic girdle
context_page_description: Falcarius is a genus of therizinosaur dinosaurs that lived during the Early Cretaceous period in what is now North America. The first fossil remains were collected in the Cedar Mountain Formation in 1999, with subsequent findings made during the 2000s. The genus is known from multiple specimens ranging from immature to fully-grown individuals.
  Falcarius were 4 m long bipedal herbivores with a small head and an elongated neck and tail. Unlike advanced therizinosaurs, Falcarius had a propubic pelvis and three-toed feet with a reduced hallux.
  Falcarius is the basalmost known definitive therizinosaurian taxon, and has been considered a transitional form connecting the typical theropod bodyplan to the unusual morphology of Therizinosauridae. Its description in 2005, following that of the basal therizinosauroid Beipiaosaurus from the Early Cretaceous of China in 1999, helped clarify the early evolution of the Therizinosauria and its relationships within the larger group of Theropoda.
context_section_description: The describers in 2005 assigned Falcarius to the Therizinosauroidea sensu of Zhang, in a basal position. Zanno later placed it as the basalmost taxon in the Therizinosauria, just outside of Therizinosauroidea sensu of Sereno.
  Because of the primitive position and relative completeness of Falcarius, it is a good taxon to use to compare to related groups and descendant taxa. Falcarius resemble dinosaurs belonging to the Therizinosauridae, part of the group Maniraptora. However, Falcarius probably does not belong to this former group, instead, this genus belong to the more inclusive group Therizinosauria. The group is characterized by wider hips, a comparatively large braincase and long necks typical of plant eaters. The less basal Asian specimens were covered in quill-like feathers; this is assumed for Falcarius as well. In general Falcarius can be seen as a transitional form between the original theropod build and the more derived Therizinosauridae. Falcarius shared some derived traits with the therizinosaurids: they had a long neck, small head with teeth adapted for eating plant material, a more robust arm with large hand-claws and a more vertical position of the body. On the other hand, they resembled more typical theropods in having a long tail, a propubic pelvis, a long lower leg and a foot without a fourth toe reaching the ground.
  The cladogram below shows the results of a phylogenetic analysis of Therizinosauria performed by Hartman et al. in 2019, based on the extensive revision by Zanno in 2010. Falcarius is recovered as the basalmost therizinosaurian taxon:
caption: The propubic pelvis of Falcarius, with the pubis pointing forwards
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