Figure 4.

Range of possible habitual head angles in the basal sauropodomorph
<b>A</b>. <i>Massospondylus</i>, and the sauropods
<b>B</b>. <i>Camarasaurus</i> and <b>C</b>. <i>Diplodocus</i>. Heads
shown with HSSC oriented horizontally, and tilted 30º upwards and 20º
downwards, the range of habitual orientations found for birds by Duijm
(1951) . Necks shown in neutral position with respect to heads with
horizontal HSCCs. Massospondylus BP/1/4376 after Sues et al. (2004:
fig. 1A), Camarasaurus CM 11338 after Gilmore (1925: pl. XVI),
Diplodocus USNM 2672 after Hatcher (1901: pl. II).