Dinosaur Jr., originally known as simply Dinosaur until legal disputes forced a name change, are an American rock band formed in Amherst, Massachusetts. It was founded by Joseph Donald Mascis Jr., Louis Knox Barlow, and Emmett Jefferson Murphy III in 1984.

After years on independent record labels, the band would begin to get recognition for their major influences on alternative rock. Despite this, J Mascis would fire Lou Barlow, causing Murph to quit the band. After hiring replacements, the band disbanded shortly after in in 1997.

In 2005, the original lineup reformed and would go on to release another five albums. During their time as a band, they changed the alternative rock scene and influenced bands such as Nirvana and TAD. They would be called “ahead of their time” by Zoe Sreet and “one of post-punks most influential bands” by the Seattle Times.