Fig. 1
From: Mechanical analysis of the wide-hipped titanosaur Savannasaurus elliottorum
“External” forces acting against a Savannasaurus. a, b Compression propagated underneath one foot (a) or two feet (b) has nearly the same value (0,25), but if two feet are loaded close to each other, nearly twice the forces are acting and therefore roughly the twofold stress is acting against homogenous ground, which sooner will give way (Data from Nobiling, 1977). c Savannasaurus, seen from above, neck held upright and therefore shortened. Within the outline, the area of support (white band) is shown between the diagonal limbs. The soles of the autopodia which carry weight during their stance-phases are emphasised in dark grey, and the ventral surface of the trunk plus proximal tail, both resting on soft, muddy ground are illustrated in light grey. The size of this area reduces the local forces exerted against the supporting underground. d Savannasaurus in anterior view, with CoM of the long neck flexed to the left of the animal. Ground reaction force Fs is directed vertical. In addition, on the right side of the animal the resultant of weight force and inertial force is shown, if the head and neck are moved to the right. It evokes the GRF named Fd and meets the ground only if the limb is sprawled. e The same animal seen from on top. The flexion of the neck to the left side causes a shift of the neck’s CoMn (marked by a dot), and makes a wide-gauged position of the forelimb useful. The same holds true for the tail (CoMt). The CoMr of the trunk (marked by a small black circle in the middle) is ignored, because it does not necessarily move with neck or tail