What is "graculavus"

Graculavus is a prehistoric bird genus that was described in the 19th century by American paleontologist O. C. Marsh. Its remains were found in the Late Cretaceous Austin Chalk of Texas, USA, and Lance Formation (late Maastrichtian faunal stage, or Lancian land mammal age), and the controversial Hornerstown Formation which straddles the Cretaceous– Paleocene boundary, possibly dating to the Danian stage. These birds lived on the shores of the northwestern Atlantic and the Western Interior Seaway some .