Morphometry of the Cervical Spine of Emu Using the Hydrostatic Method
Piotr Baranowski; Sawomir Krajewski; Jerzy Nowacki & Piotr Nowak
The study aimed at estimating the values of basic metric traits of emu cervical vertebrae. The study was conducted on the vertebrae of 6 male and 10 female emus being fourteen years old. Osteometric measurements were performed with electronic callipers, while the hydrostatic method was used to assess the density and volume of each vertebra. The sex of birds was considered a source of variation. The cervical spine had 17 vertebrae. Dimorphism was found in basic metric traits between analogous emu vertebrae of both sexes. The female vertebrae were characterised by significantly (P≤0.05 and P≤0.01) greater length, breadth and height than the male ones. No dimorphic differences were found in the volume of bone mass for vertebrae 1 to 8, whereas female vertebrae 9 to 17 had greater (P≤0.05) volume compared to the male ones. Correlation coefficients for body weight, vertebra volume and spinal canal capacity were weak. The sum of the length of vertebral bodies determining the length of neck showed significantly (P≤0.01) longer necks in female emus. No narrowing and extensions of the vertebral canal for the spinal cord running in it was found throughout the whole cervical spine.