BioConcepts

secondary sexual characterssekundäre Geschlechtsmerkmale (ger.)

• A characteristic of animals other than the organs producing gametes that differs between the two sexes (e.g., mammary glands, antlers, and external genitalia). (Oxford Dictionary of Genetics 2007)
  category sex

  1786

  The differences which are found in the parts of generation themselves, I shall call the first, or principle; and all others depending upon these I shall call secondary. The first belong equally to both [sexes]; but the secondary will be found principally, although not entirely, in the male

  Hunter, J. (1786). Observations on Certain Parts of the Animal Oeconomy; cf. Aiken, R.B. (1982). Theories of sexual difference. The sexual selection hypothesis and its antecedents, 1786-1919. Quaestiones Entomologicae 18, 1-14: 3.

  1836

  in a young male specimen [of the Homelyn Ray] of twelve inches in breadth the secondary sexual characters begin to appear

  Yarrell, W. (1836). A History of British Fishes, vol. 2: 431; cf. 417; 432.

  1836

  [In the Indian Antelope] the possession of horns and the depth of colouring [...] are peculiar to the male sex [i.e. they are] secondary sexual characters

  Bennett, E.T. (1836). [Observations on an interesting series of the Indian Antelope]. Philosophical Magazine 3rd ser. 9, 306-­311: 306.