What is "rhinosaur"

"Rhinosaur" is a song by American rock band Soundgarden on their 1996 album Down on the Upside. Despite not being released as its own single it was released as a b-side to the song " Ty Cobb". While "Ty Cobb" itself didn't chart, the b-side "Rhinosaur" charted at 19 on the Mainstream Rock Tracks.