Sauropod Vertebra Picture of the Week

Fig. 1. The pneumaticity profile of O’Connor (2006, fig. 12). The osteological correlate with the lowest specificity is at the bottom of the profile, while the correlate that specifies only pneumatic diverticula is at the top. The profile has been modified to indicate that pneumatic diverticula can form simple vertebral fossae.

Fig. 2. A simplified cladogram of sauropodomorph dinosaurs indicating the relative positions of various anchor taxa, or their inclusive clades, other taxa discussed in the paper and the higher-level taxonomy that is used. Dots represent node-based taxa, arrows represent stem-based taxa.

Fig. 3. Selected vertebrae of basal sauropodomorphs showing the three primary infradiapophyseal fossae (shaded grey) and their bounding laminae (not to scale). A. The posterior cervical, C9, of Plateosaurus engelhardti. B. The anterior dorsal, D2, of Plateosaurus engelhardti. Note that in this vertebra that the central position of the parapophysis precludes the presence of a paradiapophyseal lamina and so the AIDF and MIDF are separated by an anterior centroparapophyseal lamina. C. A middle posterior dorsal vertebra of Aardonyx celestae. Note that in this vertebra the prezygodiapophyseal lamina and the AIDF are absent. A and B are redrawn from Bonaparte (1999). Abbreviations: acdl, anterior centrodiapophyseal lamina; aidf, anterior infradiapophyseal fossa; dp, diapophysis; midf, middle infradiapophyseal fossa; pcdl, posterior centrodiapophyseal lamina; pidf, posterior infradiapophyseal fossa; podl, postzygodiapophyseal lamina; poz, postzygapophysis; pp, parapophysis; ppdl, paradiapophyseal lamina; prdl, prezygodiapophyseal lamina; prz, prezygopophysis.

Fig. 4. Cervico-dorsal transition of the vertebral column of Plateosaurus engelhardti (AMNH 6810). A. The posterior cervical vertebrae, C9 and 10, (left and middle) and the first dorsal vertebra, D1, (right) in left lateral view. B. Close-up of the pneumatic fossa on the dorsal surface of C10. Abbreviations: aidf, anterior infradiapophyseal fossa; c, centrum; il, internal lamina; ns, neural spine; pf, pneumatic fossa; pidf, posterior infradiapophyseal fossa; podl, postzygodiapophyseal lamina; poz, postazygapophysis; prdl, prezygodiapophyseal lamina; prz, prezygapophysis; r, rib. Scale for A, 200 mm; B, 50 mm.

Fig. 5. Dorsal vertebra of Eucnemesaurus fortis. A. Posterior dorsal BP/1/6107; A1, posterior; A2, right posterolateral views; A3, Close-up of the right posterior infradiapophyseal fossa in posterolateral view. B. Neural arch of middle dorsal TM 119 in right lateral view. Abbreviations: al, accessory lamina; c, centrum; hs, hyposphene; midf, middle infradiapophyseal fossa; nc, neural canal; pcdl, posterior centrodiapophyseal lamina; pidf, posterior infradiapophyseal fossa; podl, postzygodiapophyseal lamina; poz, postzygapophysis; pp, parapophysis; ppdl, paradiapophyseal lamina; prz, prezygapophysis; sf, subfossa. Scale for A1, A2 and B, 100 mm; A3, 20 mm.

Fig. 6. Neural arch of posterior cervical vertebra, ?C7, of Aardonyx celestae (BP/1/6615) in left lateral view Abbreviations: c, centrum; dp, diapophysis; ep, epipophysis; ns, neural spine; poz, postzygapophysis; pp, parapophysis; prz, prezygapophysis. Scale, 100 mm.

Fig. 7. Posterior dorsal vertebra of Aardonyx celestae (BP/1/6566) in; A, posterior; B, right posterolateral; C, left posterolateral views. Close-ups of; D, right; E, left posterior infradiapophyseal fossae. Abbreviations: c, centrum; cpol, centropostzygapophyseal lamina; dp, diapophysis; hs, hyposphene; midf, middle infradiapophyseal fossa; pcdl, posterior centrodiapophyseal lamina; podl, postzygodiapophyseal lamina; poz, postzygapophysis; pp, parapophysis; sf, subfossa. Scale for A, B and C, 100 mm; for D and E, 20mm.

Fig. 8. Sacral elements of Aardonyx celestae. A. Incomplete neural arch of first sacral vertebra (BP/1/5379); A1, left lateral; A2, posterior views; A3, Close-up of left posterior fossa in posteroventral view. Note the subfossae separated by a ridge (arrowed). B. First sacral centrum (BP/1/6241); B1, left lateral view; B2, oblique posterolateral and slightly ventral view; B3, Close-up of the dorsolateral fossa developed behind the sutural scar for the attachment of the sacral rib. Abbreviations: dlf, dorsolateral fossa; nc, neural canal; ns, neural spine; pof, posterior fossa; prz, prezygopophysis; sras, sacral rib articular surface. Scale for A1, A2, B1 and B2, 100 mm; for A3 and B3, 20 mm.

Fig. 9. Middle posterior dorsal vertebra of Antetonitrus ingenipes (BP/1/4952); A, right lateral; B, posterior views; C, left posterior infradiapophyseal fossa; D, right posterior infradiapophyseal fossa in oblique posterolateral and slightly ventral views; E, Close up of invasive left posterior infradiapophyseal subfossa. Abbreviations: cpol, centropostzygapophyseal lamina; dp, diapophysis; hs, hyposphene; il, internal lamina; midf, middle infradiapophyseal fossa; nc, neural canal; ncas, neurocentral articuloar surface; ns, neural spine; pcdl, posterior centrodiapophyseal lamina; pidf, posterior infradiapophyseal fossa; podl, postzygadiapophyseal lamina; poz, postzygopophysis; pp, parapophysis; prz, prezygopophysis; sf, subfossa. Scale for A, B, C and D, 100 mm; for C, 20 mm.

Fig. 10. Vertebrae of the Spion Kop sauropod. A. Posterior dorsal vertebra (BP/1/6183a); A1, posterior view; A2, Close-up of left posterior infradiapophyseal fossa; A3,Close-up of right posterior infradiapophyseal fossae. Note that the right subfossa cannot be seen A1 due to the oblique distortion of the specimen. B. Cervical vertebra,?C3 (BP/1/6199) in left lateral view. Abbreviations: c, cpol, centropostzygapophyseal lamina; dp, diapophysis; ep, epipophysis; hs, hyposphene; nc, neural canal; ns, neural spine; pcdl, posterior centrodiapophyseal lamina; pidf, posterior infradiapophyseal fossa; poz, postzygopophysis; pp, parapophysis; prz, prezygapophysis; sf, subfossa; spol, spinopostzygapophyseal lamina. Scale for A1 and B, 100 mm; for A2 and A3, 20 mm.

Fig. 11. Posterior dorsal vertebra of Camelotia borealis (NHM R.2873). A. Posterior view. B. Close-up of left posterior infradiapophyseal fossa. Abbreviations: c, centrum; cpol, centropostzygapophyseal lamina; hs, hyposphene; ir, internal ridge; nc, neural canal; pcdl, posterior centrodiapophyseal lamina; podl, postzygadiapophyseal lamina; poz, postzygopophysis; sf, subfossa. Scale for A, 100 mm; for B, 20 mm.

Fig. 12. A phylogenetic diagram showing the distribution of invasive PSP along the vertebral column (the caudal series is truncated) in Sauropodomorpha. Black boxes indicate the presence of pneumatic fossae or invasive infradiapophyseal subfossae. Note that in the case of Plateosaurus PSP is presently known in a single specimen whereas other specimens of same taxon lack it. The phylogeny is based on Yates (2010), with the modification that Eucnemesaurus is placed closer to Anchisauria than Massospondylus is. The position of the Spion Kop sauropod is based on an unpublished analysis (AMY unpublished data). The distributions of PSP in the taxa not directly examined in this study were gleaned from the following sources: Pantydraco (Yates 2003, Wedel 2007), Tazoudasaurus (Allain and Aquesbi 2008), Shunosaurus (Zhang 1988), Jobaria (Sereno et al. 1999), Haplocanthosaurus (Hatcher 1903).

Fig. 13. Vertebrae of the helmeted guinea fowl, Numida meleagris, (BP/4/1332) in anterior view. A. Last free cervical, C15. B. last presacral thoracic, T4. Arrows point to the main pneumatic foramina of each vertebra. Note that the pneumatic foramina occur on the anteroventral surface of the transverse processes of both vertebrae despite being formed by diverticula from different sources. In (A) the diverticula extend from the cervical air sac system whereas in (B) the foramina result from the activity of diverticula from the abdominal air sacs. Scale, 10 mm.