Lithornis nasi was a volant lithornithid, an early palaeognath with a combination of strong flight ability and relatively long legs. New Walton material has substantially improved understanding of this species and supports keeping it distinct within the London Clay lithornithid assemblage.

It probably spent much of its time walking and foraging on the ground while retaining effective flight. Small invertebrates and other ground foods are plausible, but its exact diet is not directly preserved. Lithornithids are useful reminders that early palaeognaths were not restricted to the flightless body plans familiar among many living members.