Vertebrae

Hominin evolution featured shifts from a trunk shape suitable for climbing and housing a large gut to a trunk adapted to bipedalism and higher quality diets. Our knowledge regarding the tempo, mode, and context in which these derived traits evolved has been limited, based largely on a small-bodied Aus-tralopithecus partial skeleton (A.L. 288-1; " Lucy ") and a juvenile Homo erectus skeleton (KNM-WT 15000; " Turkana Boy "). Two recent discoveries, of a large-bodied Australopithecus afarensis (KSD-VP-1/1) and two Australopithecus sediba partial skeletons (MH1 and MH2), have added to our understanding of thorax evolution; however, little is known about thorax morphology in early Homo. Here we describe hominin vertebrae, ribs, and sternal remains from the Dinaledi chamber of the Rising Star cave system attributed to Homo naledi. Although the remains are highly fragmented, the best-preserved specimensdtwo lower thoracic vertebrae and a lower ribdwere found in association and belong to a small-bodied individual. A second lower rib may belong to this individual as well. All four of these individual elements are amongst the smallest known in the hominin fossil record. H. naledi is characterized by robust, relatively uncurved lower ribs and a relatively large spinal canal. We expect that the recovery of additional material from Rising Star Cave will clarify the nature of these traits and shed light on H. naledi functional morphology and phylogeny.

Australopithecus sediba is known from two partial skeletons, Malapa Hominins 1 and 2 (MH1 and MH2), a juvenile
male and an adult female, respectively. Forty-eight elements of the axial skeleton, including vertebrae, ribs, a
sternum, and a sacrum, are known from MH1 and MH2. Here, we describe these ~2.0 Ma fossils and provide raw
data and plots of standardized measurements. We revisit the serial positions of the previously described vertebrae
and ribs proposed in their initial announcements and provide revised identifications. Additionally, we include
in our descriptions and analyses new axial material. Finally, we also test the hypothesis that multiple species are
represented in the MH1 and MH2 material and specifically that MH1’s lumbar vertebrae belong to a member of
the genus Homo, whereas those of MH2 belong to Australopithecus. We do not find support for this hypothesis, and
instead attribute differences between MH1 and MH2 to their age difference and incomplete growth of the vertebral
body in juvenile MH1.

The white shark Carcharodon carcharias has been present in the Mediterranean Sea since 3.2 million years ago. Nevertheless, the current population shows a low genetic variability suggesting an endangered small population, on which there is scarce information regarding ecotoxicology or trophic ecology. Given that white shark’s sightings are rare in the Mediterranean and the possibility of obtaining samples is highly limited, the aim of this research was to provide
general information regarding the concentration of trace elements and stable isotopes (δ15N and δ13C). Laboratory analyses were performed on 18 and 12 subsamples from two different white sharks’ vertebrae obtained from two adult specimens caught in 1987, in Favignana Island, Italy. Perforations were made along the vertebrae to describe both trace
elements and stable isotopes at different life stages. A total of 38 trace elements were analysed, in which the highest concentrations were found in Fe, Sr, U, Pb, and Zn. The fluctuations of these elements during the ontogeny of both individuals could have been related to changes in diet and environment, although the specific origin remains unknown.
Regarding stable isotopes, the vertebrae from the male showed an isotopic range from 9.6‰ to 10.8‰ (δ15N) and from −16.5‰ to −13.0‰ (δ13C) with a mean ± SD value of 10.3 ± 0.4‰ for δ15N and −14.6 ± 1.3‰ for δ13C; whereas the female vertebrae had an isotopic range from 9.8‰ to 11.1‰ (δ15N) and from −16.9‰ to −15.0‰ (δ13C), with a mean ± SD value of 10.8 ± 0.6‰ for δ15N and −15.8 ± 0.8‰ for δ13C. There were no significant δ15N differences (U = 6, p = 0.07346) between the two individuals. However, there were just significant differences in δ13C (t = −1.8, p = 0.049256), which could suggest sexual segregation in terms of habitat use and feeding habits.

Bomb radiocarbon analysis of vertebral growth bands was used to validate lifespan for sand tiger sharks (Carcharias taurus) from the western North Atlantic (WNA) and southwestern Indian Oceans (SIO). Visual counts of vertebral growth bands were used to assign age and estimate year of formation (YOF) for sampled growth bands in eight sharks from the WNA and two sharks from the SIO. Carbon-14 results were plotted relative to YOF for comparison with regional D 14 C reference chronologies to assess the accuracy of age estimates. Results from the WNA validated vertebral age estimates up to 12 years, but indicated that ages of large adult sharks were underestimated by 11–12 years. Age was also underestimated for adult sharks from the SIO by 14–18 years. Validated lifespan for C. taurus individuals in the present study reached at least 40 years for females and 34 years for males. Findings indicated that the current age-reading methodology is not suitable for estimating the age of C. taurus beyond ,12 years. Future work should investigate whether vertebrae of C. taurus record age throughout ontogeny, or cease to be a reliable indicator at some point in time.

Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little
information is available on the normal vertebral formula and congenital variants in this species. The purpose of
this retrospective study was to describe vertebral formulas and prevalence of congenital vertebral anomalies in a
sample of pet ferrets. Radiographs of 172 pet ferrets (96 males and 76 females)were included in this retrospective
study. In 143 ferrets (83.14%), five different formulas of the vertebral column were recorded with normal
morphology of vertebrae (rib attachment included) but with a variable number of thoracic (Th), lumbar (L),
and sacral (S) vertebrae. The number of cervical (C) vertebrae was constant in all examined animals. Observed
vertebral formulas were C7/Th14/L6/S3 (51.74%), C7/Th14/L6/S4 (22.10%), C7/Th14/L7/S3 (6.98%),
C7/Th15/L6/S3 (1.74%), and C7/Th15/L6/S4 (0.58%). Formula C7/Th14/L6/S4 was significantly more
common in males than in females (P < 0.05). Congenital spinal abnormalities were found in 29 ferrets
(16.86%), mostly localized in the thoracolumbar and lumbosacral regions. The cervical region was affected in
only one case. Transitional vertebrae represented the most common congenital abnormalities (26 ferrets) in
the thoracolumbar (13 ferrets) and lumbosacral regions (10 ferrets) or simultaneously in both regions (three
ferrets). Other vertebral anomalies included block (two ferrets) and wedge vertebra (one ferret). Spina bifida
was not detected. Findings from the current study indicated that vertebral formulas may vary in ferrets and
congenital abnormalities are common. This should be taken into consideration for surgical planning. C  2014
American College of Veterinary Radiology.

Spinal fusion is a standard surgical treatment for patients suffering from low back pain attributed to disc degeneration. However, results are somewhat variable and unpredictable. With fusion the kinematic behaviour of the spine is altered. Fusion and/or stabilizing implants carrying considerable load and prevent rotation of the fused segments. Associated with these changes, a risk for accelerated disc degeneration at the adjacent levels to fusion has been demonstrated. However, there is yet no method to predict the effect of fusion surgery on the adjacent tissue levels, i.e. bone and disc. The aim of this study was to develop a coupled and patient-specific mechanoregulated model to predict disc generation and changes in bone density after spinal fusion and to validate the results relative to patient follow-up data. To do so, a multiscale disc mechanoregulation adaptation framework was developed and coupled with a previously developed bone remodelling algorithm. This made it possible to determine extra cellular matrix changes in the intervertebral disc and bone density changes simultaneously based on changes in loading due to fusion surgery. It was shown that for 10 cases the predicted change in bone density and degeneration grade conforms reasonable well to clinical follow-up data. This approach helps us to understand the effect of surgical intervention on the adjacent tissue remodelling. Thereby, providing the first insight for a spine surgeon as to which patient could potentially be treated successfully by spinal fusion and in which patient has a high risk for adjacent tissue changes.