Unlike other tetradactyl salamanders, S. keyserlingii normally has the fifth tarsale, developing to fuse later with the fourth tarsale. |
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These precocious tetradactyl fliers developed a unique wing predicated upon a greatly elongated fourth finger. |
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Are trackways known in which the hind-foot impressions are tetradactyl with long, very narrow unguals? |
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The most recent tetradactyl ancestor of ameles and stylis is no more than 9.7 million years old, while that of apoda is no more than 9.2 million years old. |
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