Stable isotope tracer reveals that viviparous snakes transport amino acids to offspring during gestation.

@article{Dyke2012StableIT,
  title={Stable isotope tracer reveals that viviparous snakes transport amino acids to offspring during gestation.},
  author={James U Van Dyke and Steven J. Beaupre},
  journal={The Journal of experimental biology},
  year={2012},
  volume={215 Pt 5},
  pages={760-5}
}
Viviparity and placentation have evolved from oviparity over 100 times in squamate reptiles (lizards and snakes). The independent origins of placentation have resulted in a variety of placental morphologies in different taxa, ranging from simple apposition of fetal and maternal tissues to endotheliochorial implantation that is homoplasious with mammalian placentation. Because the eggs of oviparous squamates transport gases and water from the environment and calcium from the eggshell, the… CONTINUE READING