The general effect of this group is the best that can be had and is very realistic, particularly the crouching figure.

A fifth study will embody some further changes.

The upright figure is not well balanced and will be more effective with the feet closer together, the legs straighter and the body more erect.

These reptiles have a series of strong abdominal ribs not shown in the models.

The fourth position places the pelvis in an almost impossible position as will be noted from the ischium and pubis.
"The lateral view of this fourth pose represents the animals just prior to the convulsive single spring and tooth grip which distinguishes the combat of reptiles from that of all mammals, according to Mr.Ditmars.
"The rear view of the standing skeleton displays the peculiarly avian structure of the iliac junction with the sacral plate, characteristic of these very highly specialized dinosaurs, also the marked reduction of the upper end of the median metatarsal bone, which formerly was believed to be peculiar to _Ornithomimus_." This model of the group is on exhibition with the mounted skeleton.
As compared with its predecessor _Allosaurus_, the _Tyrannosaurus_ is much more massively proportioned throughout.