An interesting article.

Bizarre diminutive dinosaurs might help explain why no large dinosaurs survive today

Imagine a dinosaur; a sauropod such as a Brachiosaurus, or Diplodocus, one of the largest animals ever to roam the land. A plant-gobbling true giant of a beast, with a graceful long neck and tail. Now imagine that same dinosaur shrunk down to the size of a cow.

Strange as it may seem, such bizarre animals did exist. A number of astonishing fossil discoveries have confirmed that dinosaurs really did come in dwarf form. Their existence not only provides some fundamental insights into dinosaur evolution, it may even help explain why no large dinosaurs survive today.

Full story: http://www.bbc.com/earth/story/20140916-why-dwarf-dinosaurs-were-such-a-big-deal?ocid=sept_AU_outbrain_earth

Shopped.

Bubblecar said:

An interesting article.

Bizarre diminutive dinosaurs might help explain why no large dinosaurs survive today

Imagine a dinosaur; a sauropod such as a Brachiosaurus, or Diplodocus, one of the largest animals ever to roam the land. A plant-gobbling true giant of a beast, with a graceful long neck and tail. Now imagine that same dinosaur shrunk down to the size of a cow.

Strange as it may seem, such bizarre animals did exist. A number of astonishing fossil discoveries have confirmed that dinosaurs really did come in dwarf form. Their existence not only provides some fundamental insights into dinosaur evolution, it may even help explain why no large dinosaurs survive today.

Full story: http://www.bbc.com/earth/story/20140916-why-dwarf-dinosaurs-were-such-a-big-deal?ocid=sept_AU_outbrain_earth

You often hear that animals on islands become dwarfs of their former self, as if they just shrank, but what exactly would be the evolutionary drive?

Not having large predators I think would be an important factor, as animals shorter in stature on the mainland would more likely fall prey to the large predators and therefore not pass on their genes. However on a predator free island they could and therefore a size reduction seems inevitable.

Nevertheless, another factor might be the lack of food on the island or a less nutritional type that would favour the survival of smaller animals over the large.

Yet another reason might be seasonal weather conditions and available shelter being more suitable for smaller animals.

I would think that a combination of the above could dramatically reduce the average animal size relatively quickly and not the normally more sedate pace of most other evolutionary change.

It is probably a resources thing, big animals get small so they don’t starve to death and little animals get big to beat off competition.

Imagine a dinosaur; a sauropod such as a Brachiosaurus, or Diplodocus, one of the largest animals ever to roam the land. A plant-gobbling true giant of a beast, with a graceful long neck and tail. Now imagine that same dinosaur shrunk down to the size of a cow. … It is probably a resources thing, big animals get small so they don’t starve to death and little animals get big to beat off competition.

There was a really awesome comment about this on a TV show about a year back. The giant sauropods on a fairly small island had grown fairly small, but at the same time and place the pteranodons had grown huge. The net result was that the pteranodons could and would pick up the sauropods to carry back to their nests to feed their younglings.

I find this extremely non-amazing. The fact that there were very small dinosaurs is old news, and it’s not surprising there were moderate sized sauropods.

dv said:

I find this extremely non-amazing. The fact that there were very small dinosaurs is old news, and it’s not surprising there were moderate sized sauropods.

Well poo-poo to you too.

Let’s face it, deevs is grabbing at straws. For his cough theory cough to be true we’d have to see the same in other clades of the animal kingdom. It would be the equivalent of mammals having very small member, and then varying sizes up to something as big as a bloody whale.

As if.

sibeen said:

It would be the equivalent of mammals having very small member

like Victorians

sibeen said:

Let’s face it, deevs is grabbing at straws. For his cough theory cough to be true we’d have to see the same in other clades of the animal kingdom. It would be the equivalent of mammals having very small member, and then varying sizes up to something as big as a bloody whale.

As if.

Mind you:

In 170 million years, only one group of dinosaurs managed to evolve bodies less than 1 kilogram in weight: the group of dinosaurs that includes birds.

“More than 80% of living mammals weigh less than 1 kilogram,” says Benson. “Almost zero dinosaurs other than birds did.”

Bubblecar said:

sibeen said:

Let’s face it, deevs is grabbing at straws. For his cough theory cough to be true we’d have to see the same in other clades of the animal kingdom. It would be the equivalent of mammals having very small member, and then varying sizes up to something as big as a bloody whale.

As if.

Mind you:

In 170 million years, only one group of dinosaurs managed to evolve bodies less than 1 kilogram in weight: the group of dinosaurs that includes birds.

“More than 80% of living mammals weigh less than 1 kilogram,” says Benson. “Almost zero dinosaurs other than birds did.”

Given that there are tiny mammals and also the largest animal that ever lived (far as we know) is also a mammal, basically the news here is that dinosaurs had a very restrict size range. In that case the article needs a rewrite. “Dinosaurs really boring, ‘bout what you’d expect, not much variation, where’s my grant”.

The article was written in an upbeat style and a large font, presumably to appeal to the many kids who find dinosaurs interesting and don’t want to be told “dull little dinosaurs, nothing to see here”.

Well far be it from me to spoil good times.

Was this series ever shown in Oz? If so I missed it. Going to order it:

http://www.fishpond.com.au/Movies/Planet-Dinosaur-John-Hurt/5051561033896