Estimates published in 2005 and 2007 suggest that it was 12.6 to 18 metres ( 41 to 59 ft ) in length and 7 to 20.9 tonnes ( 7.7 to 23.0 short tons ) in weight .
Estimates suggest that it was 12.6 to 18 metres ( 41 to 59 ft ) in length and 7 to 20.9 tonnes ( 7.7 to 23.0 short tons ) in weight .