1. Evolution: One Penis After All
Patricia L.R. Brennan 
Current Biology 
Volume 26, Issue 1, Pages R29-R31 (January 2016)
DOI: /j.cub
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2. Figure 1
A male tuatara.
Tuatara are the only surviving member of the Rhincocephalia. Adult males like the one shown here lack a penis. (Photo: Wikimedia commons.)
Current Biology  , R29-R31DOI: ( /j.cub )
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3. Figure 2
A resolved hypothesis on the evolution of amniote external genitalia.
The presence of genital buds in the tuatara strongly supports a single origin for the amniote penis. After [10] with permission. Phylogeny after Chiari et al. [20].
Current Biology  , R29-R31DOI: ( /j.cub )
Copyright © 2016 Elsevier Ltd Terms and Conditions