Figure 3.

Phylogeny indicating high-level relationships between tetrapod groups,
habitual neck posture in extant groups, and inferred posture in
sauropods. Cervical vertebrae shaded dark grey. Lissamphibia:
<i>Ambystoma tigrinum</i>, after Simons et al. (2000: fig. 4);
Mammalia: cat, after Vidal et al. (1986: fig. 3B); Testudines:
<i>Terrapene carolina</i>, after Landberg et al. (2003, fig. 8);
Squamata: <i>Varanus exanthematicus</i>, after Owerkowicz et
al. (1999: fig. 2A); Crocodylia: alligator, after unpublished
photograph; Aves: chicken, after Vidal et al. (1986: fig. 7);
Sauropoda: <i>Diplodocus carnegii</i>, modelled after vertebrae in
Hatcher (1901: fig. 4, pl. III).