Pycnonemosaurus (meaning 'dense forest lizard') is a genus of carnivorous theropod dinosaur that belonged to the family Abelisauridae. It was found in the Upper Cretaceous red conglomerate sandstones of the "Cabembe Unit", Mato Grosso, Brazil, and it lived about 70 million years ago during the Late Cretaceous (Maastrichtian stage).