Boyer diss 2009 1046..

There are at least two basic differences between thoracic vertebrae of P. cookei
and those of N. gidleyi and N. intermedius. As mentioned previously, the vertebral canals
are proportionally larger in the smaller taxa. Additionally, the spinous processes of at
least N. intermedius are craniocaudally narrower for their proximodistal lengths
compared to those of P. cookei. The lack of a pronounced serial increase in vertebral
centrum dimensions really only contrasts P. cookei from Eulemur and Tupaia among
members of the available sample. Overall, P. cookei appears most similar to the
scansorial phalangerid marsupial Trichosurus vulpecula in the number of thoracic
vertebrae (13), the position of its anticlinal vertebra (Table 4.24), and in patterns of
change in height and length of thoracic vertebral centra.
Lumbar vertebrae
Description.—Six lumbar (L) vertebrae are preserved (Fig. 4.43). It appears that
at least one is missing based on lack of precise articulation and drastic size difference
between what appear to be L1 and L3 of the preserved series (Table 4.27; Fig. 4.43A, B).
The lumbar vertebral centra increase in all dimensions sequentially from cranial to
caudal. The spinous processes appear to become longer dorsoventrally and narrower
craniocaudally from cranial to caudal. The transverse processes are small, arise from the
vertebral body, and are cranially positioned on L1 and L3. On the remaining lumbar
vertebrae, the transverse processes are larger, arise from the base of the pedicle, and are
positioned at the craniocaudal midpoint of each element. All transverse processes project
cranioventrally to some degree. The accessory processes are largest on L1 and appear to
decrease sequentially, although breakage makes it difficult to be certain of this trend.
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