Pycnonemosaurus (meaning 'thick forest lizard') is a genus of carnivorous theropod dinosaur that belonged to the family Abelisauridae. It was found in the Upper Cretaceous Bauru-type red conglomerate sandstone, Mato Grosso, Brazil, and it lived about 70 million years ago during the Late Cretaceous (Maastrichtian stage). Initial size estimations put this animal at 7 metres (23 ft) in length, but later analyses have found that it was likely larger, being approximately 8.9 metres (29 ft) long.