English: Stenonychosaurus is a troodontid dinosaur known for having one of the largest brains, relative to body mass, of any dinosaur. Its eyes were also very large, suggesting possibility of a nocturnal lifestyle. Stenonychosaurus grew to about 2.5 m in length and had long legs for running, with large retractable claws on the second toe, similar to dromaeosaurs. Studies of troodontid nests show that multiple females would lay eggs in a single nest, which was then brooded by the male. Due to scant remains, mostly relying on their tiny teeth, classification of the troodontid family has been convoluted, and it is likely that Stenonychosaurus is the same genus as Troodon.