Theres Just No Stopping Him.

[DE&i]

My son has been learning about how animals have an effect on the planet and the environment. And as usual he likes to add his own little twist to it.These questions are always on the tip of his tongue, but being a tongue tied 7year old I’ll try to make the questions for better reading…I think.!

So at the moment the questions are:

How many Dinosaurs where there?

Did they over populate the planet or where they scattered?

How dominant were they in the landscape?

How much territory did T-Rex need and how much for a brontosaurs?

Did dinosaurs fill the air with exhaust gases and therefore warming it?

Regards,

Darren (dad)..

[Auspex]

Did they over populate the planet or where they scattered?

I can speak to this one. Situations that can be defined as 'overpopulation' are self-correcting. It is safe to say that dinosaurs dominated their niches for many millions of years, and to a large measure maintained their dominance by creating and defining those niches. When their environment changed in ways too rapid for them to adapt to, they, and the world they dominated, came to an end.

[DE&i]

"When their environment changed in ways too rapid for them to adapt"

Thats interesting Auspex..I wonder if that’s how migratory herds came to be, we have touched on the Wilder Beast before from Elliot’s planet earth DVDS.

[Auspex]

Herding, and migration, are niches themselves, which necessarily go hand-in-hand often.

[Wrangellian]

I may be out of my league here, but regarding territory/distribution, would it be safe to say that carnivores had/have larger territories than herbivores, and larger dinos in general took more than smaller ones? No idea what that would translate to in actual numbers, but at least a relative answer would be better than nothing..

[Auspex]

A very rough-but-useful concept to apply to a food chain chain is that it takes ten pounds of plants to make a pound of herbivore, and ten pounds of herbivore to make a pound of carnivore. The limiting keystone is the plants. Also, it helps to recognize that predators don't limit prey; it is the other way around.

[DE&i]

Quote: “Predators don't limit prey; it is the other way around”. Now you really got me thinking Auspex. Which came first the Predator or Prey.

Regards,

Darren.

[Auspex]

Of necessity to logic, the prey, but they really created each other.

[painshill]

I don’t think we have enough data to determine reliable estimates for absolute population numbers of particular dinosaurs – which would also have varied considerably between habitats and localities. Nevertheless, Carbone et al. took a stab at estimating the relative abundances of carnivorous theropods versus herbivores in the overall population of Cretaceous North America in their 2011 paper in the Proceedings of the Royal Society for Biological Sciences. They provided this interesting chart with estimates by body mass:

The paper was authored by Chris Carbone, Samuel T. Turvey & Jon Bielby and titled “Intra-guild competition and its implications for one of the biggest terrestrial predators, Tyrannosaurus rex”. The abstract reads as follows:

Identifying tradeoffs between hunting and scavenging in an ecological context is important for understanding predatory guilds. In the past century, the feeding strategy of one of the largest and best-known terrestrial carnivores, Tyrannosaurus rex, has been the subject of much debate: was it an active predator or an obligate scavenger? Here we look at the feasibility of an adult T. rex being an obligate scavenger in the environmental conditions of Late Cretaceous North America, given the size distributions of sympatric herbivorous dinosaurs and likely competition with more abundant small-bodied theropods. We predict that nearly 50 per cent of herbivores would have been within a 55–85 kg range, and calculate based on expected encounter rates that carcasses from these individuals would have been quickly consumed by smaller theropods. Larger carcasses would have been very rare and heavily competed for, making them an unreliable food source. The potential carcass search rates of smaller theropods are predicted to be 14–60 times that of an adult T. rex. Our results suggest that T. rex and other extremely large carnivorous dinosaurs would have been unable to compete as obligate scavengers and would have primarily hunted large vertebrate prey, similar to many large mammalian carnivores in modern-day ecosystems.

Edited April 20, 2014 by painshill

[piranha]

The online "Dinosaur Genera List" has 1440 listed as of March 2014. A few of these are dubious status so approximately 1400 looks like the correct ballpark.

DINOSAUR GENERA LIST

[DE&i]

I don’t think we have enough data to determine reliable estimates for absolute population numbers of particular dinosaurs – which would also have varied considerably between habitats and localities. Nevertheless, Carbone et al. took a stab at estimating the relative abundances of carnivorous theropods versus herbivores in the overall population of Cretaceous North America in their 2011 paper in the Proceedings of the Royal Society for Biological Sciences. They provided this interesting chart with estimates by body mass:

Relative Population Abundance.jpg

The paper was authored by Chris Carbone, Samuel T. Turvey & Jon Bielby and titled “Intra-guild competition and its implications for one of the biggest terrestrial predators, Tyrannosaurus rex”. The abstract reads as follows:

Identifying tradeoffs between hunting and scavenging in an ecological context is important for understanding predatory guilds. In the past century, the feeding strategy of one of the largest and best-known terrestrial carnivores, Tyrannosaurus rex, has been the subject of much debate: was it an active predator or an obligate scavenger? Here we look at the feasibility of an adult T. rex being an obligate scavenger in the environmental conditions of Late Cretaceous North America, given the size distributions of sympatric herbivorous dinosaurs and likely competition with more abundant small-bodied theropods. We predict that nearly 50 per cent of herbivores would have been within a 55–85 kg range, and calculate based on expected encounter rates that carcasses from these individuals would have been quickly consumed by smaller theropods. Larger carcasses would have been very rare and heavily competed for, making them an unreliable food source. The potential carcass search rates of smaller theropods are predicted to be 14–60 times that of an adult T. rex. Our results suggest that T. rex and other extremely large carnivorous dinosaurs would have been unable to compete as obligate scavengers and would have primarily hunted large vertebrate prey, similar to many large mammalian carnivores in modern-day ecosystems.

Truly fascinating stuff I always like to read wild stab in the dark scenarios when in relation to, what when and why information is trying to be fathomed about Dinosaurs. Its then always more interesting to imagine in your own minds eye how things may or may not have been.

At least for Elliot and I it is.

[DE&i]

The online "Dinosaur Genera List" has 1440 listed as of March 2014. A few of these are dubious status so approximately 1400 looks like the correct ballpark.

DINOSAUR GENERA LIST

That list is just amazing... We are having a lot of fun with that.

[DE&i]

Of necessity to logic, the prey, but they really created each other.

I think that is a question that will always be difficult to comprehend.But fun, I always through in the chicken and the egg question when Elliot's eyes start to spin from information overload.

With a shrug of the shoulders and a " I don't think anyone quite knows" approach.

[Herb]

I doubt that there were more dinosaurs emitting exhaust gases than there are herbivores now.