There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
Monolophosaurus (meaning "single-crested lizard" in reference to the holotype possessing a single crest on its skull) is a genus of tetanuran theropod dinosaur, possibly an allosauroid or a megalosauroid, from the Middle Jurassic Shishugou Formation in what is now Xinjiang, China. The holotype (IVPP 84019) was discovered in the Junggar Basin, in layers of the Wucaiwan Formation dating from the Oxfordian about 160 million years ago. It represents an adult or subadult individual, preserving everything except for the arms, legs, and most of the tail.
The animal's primary feature is a large single midline crest on its skull that extends from the premaxilla to the eye sockets, which was composed entirely of bone, highly pneumatic and very thin-walled. These traits of the crest suggest its use was not related to intraspecific or interspecific combat (where it might get bitten off or easily break with an action like a headbutt) but instead for a more non-violent purpose, such as species recognition or display.
Because of the completeness of the holotype specimen, body size estimates can be made with a relatively high degree of confidence, despite the total length being unclear due to much of the tail being unpreserved. In 2016, Gregory S. Paul gave an estimate of 5.5 meters and 475 kg.
At 80 centimeters in length, the skull was large for the animal's size, and was full of sharp, serrated teeth. The precaudal column was strongly built, making Monolophosaurus a relatively robust theropod. In the pelvis, the pubes and ischia contacted each other with a nearly vaulted closed underside.
Its phylogenetic position has varied, with different studies suggesting allosauroid affinities, megalosauroid affinities, or affinities as a tetanuran more basal than both.
