Editing Diprotodon (section)

===Life history===
The marsupial [[metabolic rate]] is about 30% lower than that of placentals due to a lower [[body temperature]] of {{cvt|34|to|36|C}}. Marsupials give birth at an earlier point in foetal development, relying on [[lactation]] to facilitate most of the joey's development; because pregnancy is much-more-energetically expensive, investing in lactation rather than longer gestation can be advantageous in a highly seasonal and unpredictable climate to minimise maternal nutritional requirements. Consequently, marsupials cannot support as large a litter size or as short a [[generation time]].<ref name=Tyndale2001>{{cite journal|last=Tyndale-Biscoe|first=C. H.|year=2001|title=Australasian marsupials—to cherish and to hold|journal=Reproduction, Fertility and Development|volume=13|issue=8|pages=477–485|doi=10.1071/RD01079|pmid=11999297 }}</ref>

Based on the relationship between female body size and life history in kangaroos, a {{cvt|1000|kg}} ''Diprotodon'' female would have gestated for six-to-eight weeks, and given birth to a single {{cvt|5|g}} joey. Given its massive size, ''Diprotodon'' may not have sat down to give birth as do smaller marsupials, possibly standing instead. Like koalas and wombats, the pouch may have faced backwards so the joey could crawl down across its mother's abdomen to enter and attach itself to a teat until it could see—perhaps 260 days—and [[thermoregulate]]. It would have permanently left the pouch after 860 days and suckled until reaching {{cvt|270|kg}} after four or five years.<ref name=Tyndale2001/>

In large kangaroos, females usually reach [[sexual maturity]] and enter [[estrous cycle|oestrus]] soon after weaning, and males need double the time to reach sexual maturity. A similar pattern could have been exhibited in ''Diprotodon''. Assuming a lifespan of up to 50 years, a female ''Diprotodon'' could have given birth eight times.<ref name=Tyndale2001/>