Question

Synsacrum of fowl consist of about
(a)29 vertebrae
(b)3 vertebrae
(c)16 vertebrae
(d)Single vertebrae

Answer 1

Hint: The synsacrum is a skeletal structure of birds and other dinosaurs in which the sacrum is extended by adding additional caudal or lumbar vertebrae fused or partially fused which can only be seen in birds.

Complete answer:
The thoracic region of the vertebral column in the fowl is Synsacrum. It consists of about 16 fused vertebrae and provides protection for the enormous pelvic girdle of the iliac bones. One thoracic vertebra, six lumbar vertebrae, two sacral vertebrae, and seven caudal vertebrae are included. In order to form a complex bone called synsacrum, some posterior thoracic vertebrae, the lumbar, sacral, and a few anterior caudal vertebrae are fused. Depending on the species, the innominate bones are fused with the synsacrum to a greater or lesser degree and form an avian pelvis. This forms a solid framework that is more comprehensive than a mammal's pelvis, meeting flight, locomotion, and breathing requirements.

Additional Information: There are a few free caudal vertebrae posterior to the synsacrum, the last of which is the pygostyle to which the long, rigid tail feathers are attached. To accommodate the glycogen body, an organ whose role is as yet uncertain but which may be associated with equilibrium, the central section of the synsacrum is swollen. The synsacrum refers to the rump in terms of outer morphology. Their transverse processes are split into parts of the dorsal and ventral. To form bony plates, the dorsal parts of these vertebrae can fuse. The section of the ventral is rod-like. It is known to be a rib.
So, the correct answer is ’16 vertebrae’.

Note: A unit formed by the fusion of the posterior thoracic, lumbar, and sacral vertebrae is the synsacrum. By minimizing the number of muscles required to regulate individual vertebrae, fusions of these bones make birds powerful and indirectly lighter. All the Synsacrum vertebrae are fully fused, and they are difficult to classify separately.