However , in 1998 Thomas Lehman claimed that a Pentaceratops specimen possessed a partial skull that would have been 2.9 metres long in life .
Based on this , Torosaurus was seen as having the longest skull of any known land animal .
In 1998 Thomas Lehman claimed that a Pentaceratops specimen possessed a partial skull that would have been 2.9 metres long in life .
Based on this , Torosaurus was seen as having the longest skull of any known land animal .