Skeletal Development
When the timing of the ossification of some groups shifts it can be regarded as a phylogenic signal. However, these shifts can lead individuals to assume impossible ancestors for the group. In the Talpa europaea there are several unique changes in ossification sequence in the postcranial elements. Many of the shifts are seen in the vertebral column, specifically the cervical and thoracic regions. The shifts allow the mole to have a more stabilized body axis and cervical region after they are born.
As the mole develops it begins to crawl around and dig. Digging causes the elements associated with the action to begin to ossify. Some elements in the hands of the Talpa, formally described as distal phalanges, are actually the first to ossify. These elements build up a groove for the distal phalanges but ultimately do not fuse with them. These bony elements develop directly, meaning they do not have any cartilaginous precursors. The extra-calcified elements are created from small, calcified particles that are found in the fibrous part of the flexor digitorum profundus. The particles then fuse later in life to form the solid element of the hand. Additionally, the sesamoid bone in the mole, sensu strictu, is a bone that develops within a tendon. It does have a chondrified precursor and it assists the tendon in transmitting force.
Read more about this topic: European Mole
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