In 2003 however, Kellner redefined Ornithocheiroidea to represent the node of "Anhanguera", "Pteranodon", "Quetzalcoatlus" and "Dsungaripterus", thus making Ornithocheiroidea a more inclusive group. Later that year, David Unwin suggested a different definition, the node that contains "Pteranodon longiceps" and "Istiodactylus latidens", as a resulting, he considered Pteranodontoidea a junior synonym of Ornithocheiroidea. Brian Andres (2008, 2010, 2014) in his analyses, converts Ornithocheiroidea using the definition of Kellner (2003) to avoid this synonymy. Andres & Myers (2013) presented a phylogenetic analysis that placed Pteranodontoidea within the group Pteranodontia, as the sister taxon of the family Nyctosauridae. In 2018 however, Longrich, Martill, and Andres revisited the classification, and concluded that Pteranodontoidea would be the more inclusive group containing both Ornithocheiromorpha and Pteranodontia. Topology A: Andres & Myers (2013). Topology B: Longrich, Martill, and Andres (2018). Pteranodontoids, like other pterosaurs, are considered to have been skilled fliers as well as adept at moving on the ground. Evidence from footprints shows that most pterosaurs did not sprawl their limbs to a large degree, as in modern reptiles, but rather held the limbs relatively erect when walking, like dinosaurs. While no pteranodontoid footprints are known, it is likely that they also walked erect. Among pterosaurs, pteranodontoids had unusually uneven limb proportions, with the forelimbs much longer than the hind limbs. This would likely have required them to use unique modes of locomotion when on the ground compared to other pterosaurs. It is possible that pteranodontoids ran (but not walked) bipedally, or that they used a hopping gait. Pterosaur researcher Mike Habib has noted that the limbs proportions of pteranodontoids like "Anhanguera" are consistent with hopping.