Unquillosaurus is a type of dinosaur that lived a long time ago during the Late Cretaceous period, about 72 million years ago. It was discovered in the Los Blanquitos Formation located in Salta Province, Argentina.
The name Unquillosaurus means “Unquillo river lizard.” This dinosaur is considered a large theropod, which is a group of dinosaurs that walked on two legs and often had sharp teeth for eating meat.
There is only one known species of Unquillosaurus, called U. ceibalii. The only fossil we have of it is a single pelvic bone called a pubis. This bone is 51.4 centimeters long, which is a bit more than 1.5 feet.
The first description of Unquillosaurus was made by a scientist named Jaime Eduardo Powell in 1979. The fossil was found near a river called Unquillo and named after a nearby town called El Ceibal.
Over the years, scientists have debated exactly where Unquillosaurus fits in the dinosaur family tree. Initially, it was thought to be related to a group of large carnivorous dinosaurs called Carnosauria. Later, other researchers suggested it might be connected to groups of dinosaurs that are more bird-like.
The last studies indicate that Unquillosaurus is likely part of a group called Maniraptora, which includes birds and other similar dinosaurs. Some researchers even think it might have been closely related to birds themselves.
Unquillosaurus lived in a rich ecosystem where other dinosaurs, like Guemesia and possibly Titanosaurus, also existed. This shows that it was part of a diverse group of creatures during its time.
In summary, while much about Unquillosaurus remains a mystery, it gives us a glimpse into the fascinating world of dinosaurs that roamed the Earth millions of years ago.