2. Bifurcated (paired) reproductive
tract
Lateral vaginae
Medial vaginal canal
(Feldhamer et al 2007)
Image: palaeo.gly.bris.ac.uk
3. Kangaroo Choriovitelline placenta
Eutherian chorioallantoic placenta
Less villi – less surface area- less gas exchange-
less gestation time
(Feldhamer et al 2007)
Kangaroo
Eutherian
Image: (Feldhamer et al 2007).
5. Kangaroo: no negative feedback loop does not
inhibit estrous cycle. Short gestation
(Sharman 1970)
Image: www.ansci.wisc.edu
6. Except grey kangaroo
Delayed implantation
Egg arrests in blastocyst stage (100
cells)
Can be pregnant, have young in
pouch and young at foot at same
time
(Renfree and Shaw 2000, Dawson 1995)
8. Temporary reduced egg shell
Lasts 2/3 of gestation
Prevents mother’s immune system
from rejecting egg
(Dawson 1995)
9. Kangaroos have short gestation and longer
lactation when compared to Eutherians
Kangaroos develop more in pouch
(Dawson 1995)
Image: www.kangaroocenter.com Image: upload.wikimedia.org
10. Can produce 2 different types of
milk synchronously
Separately controlled mammary
gland and teat for young in pouch
than for young at foot
(Krockenberger 1996; Joss et al 2009; Nicholas 1988)
11. Different composition of milk in each teat
Four phases of milk production
(Krockenberger 1996; Joss et al 2009; Nicholas 1988)
Image: 1.bp.blogspot.com
12. Forelimbs must develop quickly to be usable
for climb to pouch
Hindlimbs have more time to develop
Forelimbs show much less diversity
Hindlimbs show much more diversity
(Cooper and Steppan 2010).
14. Cooper, James W., and Scott J. Steppan. 2010. Developmental constraint on the
evolution of marsupial forelimb morphology. Australian Journal of Zoology 58: 1-
15.
Dawson, Terence J.. 1995. Kangaroos: Biology of the Largest Marsupials. Cornell U.
P., Ithaca, New York.
Feldhamer, George A., Lee C. Drickamer, Stephan H. Vessey, Joseph F.
Merritt, and Carey Krajewski. 2007. Mammalogy: Adaptation, Diversity, Ecology.
Third ed. The Johns Hopkins U. P. Baltimore, Maryland.
Joss, Janice L., Mark P. Molloy, Lyn Hinds, and Elizabeth Deane. 2009. A
longitudinal study of the protein components of marsupial milk from birth to
weaning in the tammar wallaby (Macropus eugenii). Developmental and
Comparative Immunology 33: 152-161.
Krockenberger, Andrew K. 1996. Composition of the milk of the
koala, Phascolarctos cinereus, an arboreal Folivore. Physiological Zoology 69(3): 701-
718.
Nicholas, Kevin R.. 1988. Asynchronous dual lactation in a marsupial, the tammar
wallaby (Macropus eugenii). Biochemical and Biophysical research Communications
154(2): 529-536.
Renfree, M.B., and G. Shaw. 2000. Diapause. Annual Review of Physiology 62: 353-
375.
Sharman, G.B.. 1970. Reproductive physiology of marsupials. Science 167(3922)
1221-1228.