The most spectacular, found in 2007, is the two beasts that killed one another. Their fossil skeletons were sold in a single lot by Heritage for $ 2.75M including premium on 12 June 2011. The allosaurus from this terrible couple was 6.30 m long and 70% complete.
Juvenile specimens are extremely rare, perhaps because their death was often due to predators that showed poor respect for the integrity of their bones. They are interesting by the proportions of their limbs still in growth phase. The first excavation of the bone of a young allosaurus in Wyoming was performed in 2006.
On November 25 in their gallery surrounded by gardens in Sussex, Summers Place Auctions sells the fossil skeleton of a juvenile allosaurus 2.85 m long, complete over 50% (although the actual rate is not identified in the catalogue). It is estimated beyond £ 300K, lot 55.
I had indeed an intuition in previous posts that recent technical improvements favored the excavation of increasingly complete specimens. The press release published by Summers Place provides fascinating details.
The first bone of the allosaurus for sale was found in 2010. An initial assessment by geologists is now considered essential before digging around the skeleton, to establish both the hardness of the rock and the brittleness of the fossil. The species must be identified early for guiding the search for the bones remaining within the rock.
The painstaking work of the excavation of this skeleton spanned three seasons. It was laying over the fossil of a large sauropod which was the subject of a similarly careful processing.