New study sheds light on dinosaur size

Dec 19, 2012

Dinosaurs were not only the largest animals to roam the Earth - they also had a greater number of larger species compared to all other back-boned animals - scientists suggest in a new paper published in the journal PLOS ONE today.

The researchers, from Queen Mary, University of London, compared the size of the femur bone of 329 different from . The length and weight of the is a recognised method in palaeontology for estimating a dinosaur's body mass.

They found that dinosaurs follow the opposite pattern of body size distribution as seen in other . For example, within living mammals there tends to be few larger species, such as elephants, compared to smaller animals, such as mice, which have many species. The evidence from fossil records implies that in contrast there were many species of larger dinosaurs and few small species.

Dr David Hone from Queen Mary's School of Biological and Chemical Sciences, explains: "What is remarkable is that this tendency to have more species at a bigger size seemed to evolve quite early on in dinosaurian evolution around the Late , 225 million years ago, raising questions about why they got to be so big.

"Our evidence supports the hypothesis that young dinosaurs occupied a different to their parents so they weren't in competition for the same sources of food as they ate smaller plants or preyed on smaller size animals. In fact, we see modern crocodiles following this pattern - baby crocodiles start by feeding off insects and tadpoles before graduating onto fish and then larger mammals."

Dr Eoin Gorman, also from Queen Mary's School of Biological and Chemical Sciences added: "There is growing evidence that dinosaurs produced a large number of offspring, which were immediately vulnerable to predation due to their smaller size. It was beneficial for the herbivores to grow to large size as rapidly as possible to escape this threat, but the carnivores had sufficient resources to live optimally at smaller sizes.

"These differences are reflected in our analyses and also offer an explanation why other groups do not follow a similar pattern. Several modern-day vertebrate groups are almost entirely carnivorous, while many of the herbivores are warm-blooded, which limits their size."

Explore further: Grant Museum starts major project to preserve rarest skeleton in the world

More information: "Body size distribution of the dinosaurs" will be published in the journal PLOS ONE on Wednesday 19 December 2012. dx.plos.org/10.1371/journal.pone.0051925

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User comments : 5

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Lurker2358
1 / 5 (9) Dec 19, 2012
"Dinosaur" is far too broad of a classification for animals, because they have morphology that are so drastically different.

Two legs
four legs
duck bill
normal
herbivore
carnivore
horns
no horns
flies
doesn't fly
feathered
no feathers
claws
no claws
30tons
3 tons
30 pounds
3 pounds
long nech
short neck
dorsal sail

It's only barely more descriptive than "animal" or "plant".
clay_ferguson
1 / 5 (10) Dec 20, 2012
Maybe the dinousar genome (DNA) originated on a planet with much more mass than the earth requiring larger and thicker bones, and after some supernova that binary pattern of atoms (all that's require to get life started) happened to land on the earth. Once that DNA code landed in a warm puddle it would have a chance to mix with nutrients, take over some cells, and replicate and get started on this planet. DNA may be something that is evolving in our universe, and just gets spread every time there is a supernova.
Ojorf
1.7 / 5 (6) Dec 20, 2012
'"Dinosaur" is far too broad..'
Just like stupid "mammal", far to broad to be useful:
Two legs
four legs
duck bill
normal
herbivore
carnivore
horns
...
...
jsdarkdestruction
3 / 5 (6) Dec 20, 2012
Maybe the dinousar genome (DNA) originated on a planet with much more mass than the earth requiring larger and thicker bones, and after some supernova that binary pattern of atoms (all that's require to get life started) happened to land on the earth. Once that DNA code landed in a warm puddle it would have a chance to mix with nutrients, take over some cells, and replicate and get started on this planet. DNA may be something that is evolving in our universe, and just gets spread every time there is a supernova.

So you are saying the dinosaurs dna came to this planet and it took over some early life forms somehow and turned into dinosaurs again? really? wow...
Shinobiwan Kenobi
1 / 5 (6) Dec 26, 2012
So you are saying the dinosaurs dna came to this planet and it took over some early life forms somehow and turned into dinosaurs again? really? wow...


Dunno, seems legit after seeing this:

http://dawnchapel...me-over/

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