But the prevalence of the pentadactyl limb argues just the opposite: That for whatever prehistoric reasons, an ancestral tetrapod had five digits per limb, and all of its descendants did as well.

This early tetrapod from the side of the road in Clinton ... We can see the internal bony structure that showed it was a muscular fin; it probably had a lot of muscle attachments within the ...

Sitting on top of a granite base are numerous concrete tetrapods weighing more than two tons each. They are placed carefully in position and locked with each other to create a formidable structure.