http://upload.wikimedia.org/wikipedia/commons/d/d6/Gray1119.png

The eminence in the embryo which develops into the clitoris or penis. [TFD][VHOG], embryonic anlage of the external genitalia, which emerges as paired swellings ventral to the cloacal membrane, is proposed to be derived from all three germ layers, and gives rise to the penis, clitoris, scrotum, labia, and foreskin; GT development is indistinguishable in male and female mouse embryos until ~E16, when the urethral plate begins to be masculinized to form the penile urethra, marking the beginning of an androgen-dependent phase of sexual differentiation[MP]

we assume the EMAPA class is the undifferentiated form based on TS timings

uberon

phallic tubercle, genital tubercle, tuberculum genitale, tuberculum phallicum

In mammalian embryos, male and female external genitalia develop from the genital tubercle.[well established][VHOG]

UBERON:0005876

GT development is indistinguishable in male and female mouse embryos until approximately E16, when the urethral plate begins to be masculinized to form the penile urethra, marking the beginning of an androgen-dependent phase of sexual differentiation[MP:0011771], All amniotes studied to date initiate external genital development with the formation of paired genital swellings. In mammals, archosaurs, and turtles, these swellings merge to form a single genital tubercle, the precursor of the penis and clitoris[PMID:24960313], todo - add taxon constraints

• clitoris
• penis
• differentiated genital tubercle

• genital swelling
• preputial swelling