 Further research has found medullary bone in the theropod "Allosaurus" and ornithopod "Tenontosaurus".Because the line of dinosaurs that includes "Allosaurus" and "Tyrannosaurus" diverged from the line that led to "Tenontosaurus" very early in the evolution of dinosaurs, this suggests that dinosaurs in general produced medullary tissue.Several "Citipati" specimens have been found resting over the eggs in its nest in a position most reminiscent of brooding.