Dinosaurs Grew Fast and Bred Young

Smivs writes "It is thought that dinosaurs were able to breed before they were fully grown, much like todays mammals. This ensured that they could breed before they were predated in the violent world of the Mesozoic era. Calcium-rich medullary bone, which, in birds, is used to produce egg shells, was found inside the fossilized shin-bones of two specimens: the meat-eating Allosaurus and the plant-eater Tenontosaurus.Sarah Werning and Andrew Lee of the University of California, Berkeley, deduced from growth rings inside the bone that the two females were aged eight and 10, very young for dinosaurs, which lived to about 30. 'This shows us beyond any doubt how fast dinosaurs grow,' said Kevin Padian, a professor at UC Berkeley's Museum of Palaeontology. 'They're growing as fast as big birds and big mammals.'"

Comments

Humans too...

[psychicsword]

There are example of humans breeding commonly at young ages too.
In the middle ages it was common for children to get married and although they tended to have kids when they where older, this wasn't always the case.
A quick google search turned this up:

It is more common for a young woman to have been married early, though not to have had her first child until she was much older. It is agreed that the most common age for a young woman to have given birth to her first child is from 16yo. In the middle ages with death all around from acts of god(viruses) and where large and very long wars were common it seems that humans did a similar thing.
Also from what I remember from studying the Middle Ages in school they had around a 40 year life expectancy which is very similar to the Dinos' life expectancy "two females were aged eight and 10, very young for dinosaurs, which lived to about 30." I understand it isn't the best source but like I said it was a quick search you may find another one if you wish.

If you want an example from more recently here is one.

According to their own estimate of total population (which is another contentious issue), this implies that around 5.5 million South Africans were living with HIV at the end of 2005, including 240,000 children under 15 years old. Now this doesn't mean they are giving birth to kids but they are sexually active and those are just the ones with HIV.
Now I know this isn't evidence but it is a possibility and I wouldn't be surprised if the dinosaurs did it.
PS I am just throwing this out I have no experience in the area and it is just a thought. So please nicely correct me if I am wrong.

Re:Humans too...

[Chris Burke]

Also from what I remember from studying the Middle Ages in school they had around a 40 year life expectancy which is very similar to the Dinos' life expectancy "two females were aged eight and 10, very young for dinosaurs, which lived to about 30."

Just a note about these two numbers. "Life expectancy" is an average value that takes into account the length of time that everyone lives, regardless of cause of death, and like all averages without any other context this can skew your perception. It's not that people died of "old age" at around 40 (presumably due to the harsh life they lived), they could easily live to be 60, 70, or even older. It's that a huge number of people died when they were very young, dragging down the average. What that 40 year life expectancy is really showing you is the effect of the extremely high infant mortality rate in that period.

Whereas the number for dinosaurs is intended to be more of an "upper bound". I don't know how they figure it, but it isn't meant to be the average lifespan of all members of the species, even those killed young. It's more like, that's about the age of the oldest specimens they've found.

Re:Humans too...

[BeanThere]

The odds of getting HIV from a blood transfusion in South Africa is incredibly miniscule, all our blood is tested. The vast, vast majority of infections is via sexual activity. It's definitely safe to say that the majority of that 240,000 got HIV from some form of sexual activity, so I think the point stands.

Re:Humans too...

[damn_registrars]

including 240,000 children under 15 years old.
HIV can also spread from the mother to the fetus. Those children under 15 could be a population of children who received the virus from their mother, but have not yet died of the virus.

Although it is possible that some portion of those under-15 children could be sexually active, as well. However, if you scroll further down the same page, you'll see that of the three age groups under 15 (2-4, 5-9, and 10-14), the youngest of the three actually has the highest percent prevalence. This could be indicative of a high rate of transfer of the virus from mother to fetus, with the infected newborn generally living to be around 4 years old.

Re:Humans too...

[Codifex Maximus]

>> Is that not what I am saying they had many who died very very young and made the rest reproduce like rabbits to compensate for the death.

I have to agree with this statement. Look at family statistics here in the U.S.A. prior to around 1940. Family pictures often show a long line of kids from short to tall. Infant mortality was a very real thing and families were larger back then - pretty much had to be. Heck, after WWII, there was this thing called the Baby Boom to replenish the population.

By the way, rabbits are the perfect example. They reproduce fast and young because they are a primary food animal for many predators. If they didn't reproduce the way they do then they would be extinct.

Poor Dinosaurs...

[__aaclcg7560]

...were aged eight and 10, very young for dinosaurs, which lived to about 30.

And some people still think Logan's Run is science fiction.

To be young again...

[katterjohn]

and also a dinosaur

Re:Don't tell the religious

[Bryansix]

The Bible doesn't say anything about age of consent. It is stupid people who can't see past their own culture who manufacture this crap up.

I detect a pattern

[themushroom]

> Dinosaurs Grew Fast and Bred Young

So do urban humans. Did dinosaurs have rap music too?

Re:I detect a pattern

[SpaceLifeForm]

Maybe, but Fred was into rock.

Re:Don't tell the religious

[jollyreaper]

The Bible doesn't say anything about age of consent. It is stupid people who can't see past their own culture who manufacture this crap up. You liberal pervert. Next you're going to say that the dinosaurs can procreate outside of wedlock. That just isn't right!

Partially correct.. but wrong on substence

[Actually, I do RTFA]

"Life expectancy" is an average value that takes into account the length of time that everyone lives, regardless of cause of death, and like all averages without any other context this can skew your perception. It's not that people died of "old age" at around 40 (presumably due to the harsh life they lived), they could easily live to be 60, 70, or even older. It's that a huge number of people died when they were very young, dragging down the average. What that 40 year life expectancy is really showing you is the effect of the extremely high infant mortality rate in that period.

You're right that when most people say "Life expectancy" they mean at birth. However, life expectancy changes as a person ages, as the remaining amount of time a person will live (on average). To correct for high infant mortality, the life expectancy can be taken at 5 or 10 years. In this case, the numbers indicate that 40 years was excluding the infant morality. Please note, this numbers are when the Black Plague was at its least virulent.

Age Remaining Total 00 31.3 31.3 10 32.2 42.2 20 25.2 45.2 30 21.8 51.8 40 16.6 56.6 60 08.3 68.3 80 03.8 83.8