Sophie the Stegosaurus

The Natural History Museum in London is famous for it's dinosaurs, yet it's most iconic, Dippy the Diplodocus in the entrance hall is actually one of ten plaster casts of a dinosaur in Pennsylvania and it now has a rival - Sophie the stegosaurus

Named after the daughter of the benefactor who helped pay for it, this young dinosaur (whose gender is actually unknown) is 85% complete is the most complete stegosaurs yet found.

And it makes a mesmerising display in the Earth Hall when entering via Exhibition Road.

.

Sophie is a Stegasarus stenops and belongs to the group of dinosaurs known as the stegosaurs which are defined by their heavy body armour and defensive tail spines.
.

.
Sophie isn't the only stegosaur at the Natural History Museum, located across from the vast display of itchyosaurs are the fossilised remains of a Dacentrurus armatus:
.

.
Whilst not as impressive as Sophie - consisting of only a pelvis, vertebrates, femur and the defining tail spine -  it is the first ever stegosaur to be described and whilst Sophie was found in Wyoming in 2003, this one found in Swindon in 1875.

Reference:

The Guardian: http://www.theguardian.com/science/2014/dec/04/sophie-stegosaurus-london-natural-history-museum

Dinosaurs of the British Isles by Dean Lomax: http://www.deanrlomax.co.uk/Books.html