Olorotitan was considered larger than other hadrosaurs at some point, but paleontologists re-examined it and found it to have a more regular size.
It's more accurate but less spectacular, so I'm also a bit disappointed.
Where did these false reports of
Olorotitan being a giant come from? It has always been an average-sized (8-9m long) lambeosaurine since the initial description. Scientists haven't "downsized" it, it is known from an almost complete skeleton so there was never any confusion about how big it is.
Godefroit et. al 2003 = describes holotype (= largest, most complete individual) as "...comparable in size to
Parasaurolophus cyrtocristatus", presents a c.8.5m long skeletal reconstruction.
2007 = 9m long skeletal mount of Olorotitan unveiled at the Natural History Museum of Brussels.
Paul 2010 = gives an 8m (26ft) length for Olorotitan.
Godefroit et. al 2012 = provides rigorous measurements for all holotype bones = substantially smaller animal than a mature
Edmontosaurus.