sentence: Identical twins are normal in a few species.
sentences_before: Twinning is normal in many mammals, such as rats, cats, dogs.
sentences_after: The nine-banded armadillo, 'Dasypus novemcinctus', gives birth to identical quadruplets. Cyranoski D. 2009. 458', p826.Newman H.H. Patterson J.T. 1909.
concept_name: identical twin
headings: Identical twins Twins in animals
categories: Biological reproduction Developmental biology Classical genetics