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Thursday, January 17, 2008 | Science : Evolution and Biology | print version Print | Comments

Document Gigantic fossil rodent discovered

by BBC

Thanks to Geoff for the link.

Reposted from:
http://news.bbc.co.uk/1/hi/sci/tech/7189341.stm

The fossilised skull of the largest rodent ever recorded has been described by scientists for the first time.

rodent 1

The remains of the one-tonne beast, found in Uruguay, indicate that it would have been as big as a bull.

It is thought that the three-metre-long herbivore would have roamed estuaries and forests 2-4 million years ago.

The mammal, which is more than 15 times heavier than the largest living rodent, is described in the journal Proceedings of the Royal Society B.

The authors say the animal would have lived alongside carnivorous "terror birds" and sabre-toothed cats.

"If you are a rodent you cannot run so well so you would have had to fight with these predators," said Dr Rudemar Ernesto Blanco of the Institute of Physics in Montevideo, Uruguay, one of the authors of the paper.

"It might have reached this size to protect itself."

Fighting giants

The half-metre-long fossil skull was discovered by an amateur palaeontologist in a boulder on the Rio de La Plata coast in the south of the country.

The remains had lain in the Museum of Natural History in Montevideo for three years before being studied and identified as a new species, Josephoartigasia monesi.

rodent 2It was recognised as a new creature by examining and comparing its teeth with other known species of Josephoartigasia.

"Its incisors are extraordinarily large - much larger than any other rodent," said Dr Blanco.

The researchers have speculated that the creature may have used the teeth to cut wood in a similar way to a modern day beaver.

"The other possibility is that they used them for fighting."

The team spent nearly one year estimating the body mass by comparing the skull with other living South American rodents.

Most weigh less than 1kg. However, there are exceptions such as the 60kg capybara (Hydrochoerus hydrochaeris), and the closest living relative of the newly discovered creature: the pakarana (Dinomys branickii).

The comparisons allowed them to estimate the creature's weight at nearly one tonne (1,000kg) and predict its length.

"We think it was around three metres from the tip of the nose to the tail," said Dr Blanco.

The creature's tail would have been little more than a stump, according to the team.

Island paradise

The skull is not the first oversized creature to be discovered in South America.

Other finds have included car-sized armadillos, giant ground sloths and hook-beaked terror birds.

The previously largest-known rodent was Phoberomys pattersoni, a 700kg creature nicknamed "guinea-zilla" and discovered in Venezuela.

South America is well studied by biologists because its plants and animals developed in isolation to the rest of the world's flora and fauna.

Until the emergence of the isthmus of Panama, connecting it to Central and North America about three million years ago, the landmass had been cut off for tens of millions of years.

"It is highly probable that we can find more material of this fossil and other related species," said Dr Blanco.

rodent 3

Comments 1 - 42 of 42 |

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1. Comment #112593 by Animavore on January 17, 2008 at 2:10 pm

 avatarWOW! Imagine the size of the mouse-traps they had to use!

Other Comments by Animavore

2. Comment #112595 by al-rawandi on January 17, 2008 at 2:12 pm

 avatarFossil Rodent...


I have already seen Dinesh D'Souza.

Other Comments by al-rawandi

3. Comment #112596 by anthropicOne on January 17, 2008 at 2:12 pm

 avatarReal "ROUS's", as in The Princess Bride. I LOVE it!

Other Comments by anthropicOne

4. Comment #112609 by octopus on January 17, 2008 at 2:29 pm

Good news for creationists. Number of "missing links" has just increased...again... :D

Other Comments by octopus

5. Comment #112610 by Matt7895 on January 17, 2008 at 2:30 pm

 avatar2-4 million years ago? The devil is lying to you. The earth is only 6000 years old.

Seriously though, a one-tonne rodent? Hard to imagine! Interesting find, though.

Other Comments by Matt7895

6. Comment #112619 by notsobad on January 17, 2008 at 3:07 pm

 avatar
Real "ROUS's", as in The Princess Bride. I LOVE it!

That gem of a film has everything in it.

Other Comments by notsobad

7. Comment #112627 by chickenfoot on January 17, 2008 at 3:30 pm

 avatarMan!! That's one big beaver.....

Other Comments by chickenfoot

8. Comment #112634 by The Smart Patrol on January 17, 2008 at 3:56 pm

 avatarIt's very sad that we will never really know what life would have been like 2.4 million years ago for these extraordinary creatures, or what they really looked like when they were moving around. Terror birds, giant rats and sabre-toothed tigers, all occupying the Earth at the same time as our early ancestors were struggling to make a life for themselves on the forest floor. Life for primates back then must have been absolutely terrifying. Imagine being stuck up a tree and having a ten foot tall terror bird squawking up at you, or being chased through the savanna by a pack of ravenous smilodons. How we ever managed to make it through that lot beggars belief.

Other Comments by The Smart Patrol

9. Comment #112637 by Steve Zara on January 17, 2008 at 4:06 pm

 avatar
Fossil Rodent...


I have already seen Dinesh D'Souza.


I am afraid this has given me a wicked thought. When Creationists say "If evolution were true, then where is the half-man-half-rat?" ...

Other Comments by Steve Zara

10. Comment #112640 by JamieR on January 17, 2008 at 4:15 pm

 avatarIt looks like a bird to me

Other Comments by JamieR

11. Comment #112643 by Gymnopedie on January 17, 2008 at 4:23 pm

Sheesh, I remember seeing the giant capybaras at the Detroit Zoo and being amazed at those oversized guinea pigs. Too bad we don't have one of those!

Other Comments by Gymnopedie

12. Comment #112657 by Alkal on January 17, 2008 at 5:02 pm

A mouse that size....
how big was the cat???


Wow

Other Comments by Alkal

13. Comment #112683 by Zakie Chan on January 17, 2008 at 7:57 pm

 avatarEh, its pretty big... I guess.

I would like to see it battle a saber tooth tiger.

Other Comments by Zakie Chan

14. Comment #112695 by flyingfsck on January 17, 2008 at 9:58 pm

They haven't got much really, just half a skull. It is amusing how the article talks about the extraordinary long teeth, while the fossil doesn't actually have any, and the whole body is an extrapolation from very little. Oh well, I guess they wanted publicity to raise funding...

Other Comments by flyingfsck

15. Comment #112696 by Roland_F on January 17, 2008 at 10:24 pm

14. Comment #112695 by flyingfsck
They haven't got much really, just half a skull. It is amusing how the article talks about the extraordinary long teeth, while the fossil doesn't actually have any, and the whole body is an extrapolation from very little

Paleontologist are very good at this extrapolations. When you know the usual length to width ratio of rodent teeth, you can estimate the length of a bigger tooth. When you know how deep the teeth are rooted inside the skull you can calculate also the length, and from this the force they can withstand without breaking off all the time. And cross check all these calculations.
Ancient fossils found are sometimes limited to a jawbone, skull fragment etc.. and paleontologist recalculating the entire body from this tiny information.

Of course this can lead to extrapolation errors, where a disabled skeleton might be misinterpreted as some new species, and cretinist happily jumping on every small mistake.

Other Comments by Roland_F

16. Comment #112697 by robotaholic on January 17, 2008 at 10:25 pm

 avatarI like how they spent nearly a year estimating its bodymass by comparing it to other rodents - the care spent is what gives science its credibility. Science is truely awesome. It seems funny that science needs publicity in the usa when there are discoveries like these. I wonder how the creationist crowd who think humans & dinosaurs lived together put this rat on the ark lolllll

Other Comments by robotaholic

17. Comment #112698 by dlitt on January 17, 2008 at 10:58 pm

 avatarIf only I'd known about this before I saw that big mouse at Disneyland.

Other Comments by dlitt

18. Comment #112699 by LorienRyan on January 17, 2008 at 11:04 pm

 avatarDon't think jumping on a chair would help if I saw one of those in the kitchen.

Other Comments by LorienRyan

19. Comment #112700 by dlitt on January 17, 2008 at 11:08 pm

 avatarOnly if you saddled it up.

Other Comments by dlitt

20. Comment #112704 by LorienRyan on January 17, 2008 at 11:24 pm

 avatarYou saw what happened to Anakin Skywalker when he tried that in episode II

Other Comments by LorienRyan

21. Comment #112711 by Cartomancer on January 18, 2008 at 12:32 am

 avatarRodents, from the latin "Rodentes", nominative or accusative plural present-participial adjective meaning those involved in chewing, gnawing or biting. And with teeth like that I think this one pretty much exemplifies the order.

These ancient giant rodents frighten me. Make them go away...

Other Comments by Cartomancer

22. Comment #112757 by bluebird on January 18, 2008 at 3:51 am

 avatarHow much wood could a woodchuck chuck......

Punxsutawney Phil is jealous.

Other Comments by bluebird

23. Comment #112811 by JSW on January 18, 2008 at 6:03 am

Heeere it comes to save the daaaay!

Other Comments by JSW

24. Comment #112816 by jdb on January 18, 2008 at 6:17 am

 avatar"Gigantic fossil rodent discovered by BBC"

Wow, the BBC has really become diversified. Or else they really need to get a new office building.

Other Comments by jdb

25. Comment #112817 by Johnny O on January 18, 2008 at 6:19 am

 avatarHow did it get so big when there wasn't any cheese yet?

Other Comments by Johnny O

26. Comment #112823 by annabanana on January 18, 2008 at 6:28 am

 avatar*hits forehead on desk*

Now the creationists have something else to depict alongside the humans in the new Creationism museum...they thought it was complete...[/sarcasm]

Other Comments by annabanana

27. Comment #112827 by epeeist on January 18, 2008 at 6:38 am

 avatarComment #112823 by annabanana

Now the creationists have something else to depict alongside the humans in the new Creationism museum

They need to put some microbes in there as well - http://www.answersingenesis.org/articles/arj/v1/n1#microbes-days-of-creation

Perhaps the reason god didn't allow A&E to eat the apple was because they had no intestinal fauna to digest it.

Other Comments by epeeist

28. Comment #112856 by Geoff on January 18, 2008 at 7:36 am

 avatarMy daughter wants one to keep as a pet - I made the mistake of showing her the article when I submitted it to Josh.
I guess the gerbils are going, then...

Other Comments by Geoff

29. Comment #112864 by annabanana on January 18, 2008 at 7:44 am

 avatarLol! It's the new pony! "Daddy, I want a Josephoartigasia monesi for my birthday! Please!!!!!"

Other Comments by annabanana

30. Comment #112882 by Ultraviolet G on January 18, 2008 at 8:11 am

Notsobad beat me to it but...

"Rodents of Unusual size...? I don't think they exist. (AARGH!)"

Other Comments by Ultraviolet G

31. Comment #112884 by epeeist on January 18, 2008 at 8:20 am

 avatarComment #112882 by Ultraviolet

Notsobad beat me to it but...

"Rodents of Unusual size...? I don't think they exist. (AARGH!)"
Someone who hasn't been to an under-13 fencing competition...

Other Comments by epeeist

32. Comment #112899 by DamnDirtyApe on January 18, 2008 at 8:58 am

 avatarIn other news, four giant turtle fossils were found in close proximity.

*spot the gag.

Other Comments by DamnDirtyApe

33. Comment #112933 by flobear on January 18, 2008 at 9:52 am

 avatarMore evidence for my hypothesis that God made all modern animals from Shrinky-dinks.

Other Comments by flobear

34. Comment #113008 by konquererz on January 18, 2008 at 12:36 pm

 avatarWow, if that rodent were still alive, Taco Bell would SOOO be toast!

Other Comments by konquererz

35. Comment #113012 by LorienRyan on January 18, 2008 at 12:44 pm

 avatarDid this rodent start the rat race.

Other Comments by LorienRyan

36. Comment #113014 by steveroot on January 18, 2008 at 12:48 pm

 avatar
27. Comment #112827 by epeeist on January 18, 2008 at 6:38 am

Perhaps the reason god didn't allow A&E to eat the apple was because they had no intestinal fauna to digest it.

Minor correction, please! That would be "flora"; there are sometimes "fauna" in the GI tract, but they are generally there as parasites, and have little to do with digestion. An example would be Giardia lamblia (aka "the little old man"); see
http://www.cdc.gov/Ncidod/dpd/parasites/giardiasis/factsht_giardia.htm
Steve

Other Comments by steveroot

37. Comment #113063 by Corylus on January 18, 2008 at 2:07 pm

 avatar
The mammal, which is more than 15 times heavier than the largest living rodent, is described in the journal Proceedings of the Royal Society.
Hmmph!!

Waits for the "Your Momma is so fat..." jokes.

Other Comments by Corylus

38. Comment #113076 by Richard Morgan on January 18, 2008 at 2:20 pm

 avatar
Other finds have included car-sized armadillos,
And Smart invented the armadillo-sized car!
No room for a creator-god in all that, I'm afraid. (Though I sometimes wonder what supernatural force could have created the Ferrari 599 GTB Fiorano...)

Other Comments by Richard Morgan

39. Comment #113106 by D'Arcy on January 18, 2008 at 2:57 pm

 avatarWell this rodent may not have been the designer of the Ferrari, but did it have to do battle with Argentinasaurus, bigger than T. Rex by far? Probably not, because of a time span of some 55 million years. Never mind, more gaps in the fossil record for Creationosaurus to fall into.

Other Comments by D'Arcy

40. Comment #113199 by BMMcArdle on January 18, 2008 at 9:16 pm

Thufferin' Thuccotash!

Other Comments by BMMcArdle

41. Comment #113377 by sent2null on January 19, 2008 at 1:13 pm

 avatarRe comment 32

TMNT?

Don't see the relevance though...

Regarding the article, this discovery is more elegant confirmation that evolution has very predictable patterns on the flora and fauna in an environment. In the case of South America prior to the connection of the Isthmus the development of large mammals went hand in hand with what we know about the fauna that existed there at the time. South America is not known for any large land based non avian carnivores. (it does have some reptiles but they are mostly restricted to wet habitats) The Carnivorous mammals dominated the Northern continent with large populations of Smilodon, Dire Wolves and Bear ancestors and related species enacting a very "Savanah" like existence in the North American content while hunting proto horses, proto Bison and Mastodon's as well as other large herding herbivorous creatures. The connection of the land bridge opened the flood gates on the large rodents of the Southern continent, which got so large precisely because a) the flora accommodated it by being plentiful and b) the lack of predation on "big and slow" individuals. The connection allowed the carnivorous mammals of the north that had evolved with herding herbivores free reign into the territory of the Southern herbivores and that surely expedited the end of many species, that despite their size were no match for the Smilodon and wolves that evolved to take large herbivores down in the north and the pressures they placed on the existing species through their predation. No doubt the emergence of the ice age cycles around this time also led to great turmoil for species world wide leading to the extinction or adaptation of many of them.


I would love to see a video made that in say an hour span, provides an illustrated look at ancient history as we know it going back oh 65 million years. I've seen clips like it on countless series, "Blue Planet", "The Planets", "Walking with Dinosaurs"..but I'd like to see a full length animation, without the interruptions for narration..simply letting the video do all the talking. The video would chronicle the rise of mammals around the demise of the dinosaurs and the camera would flow freely as a ticker clocks time from the past to the present , slowing and speeding where necessary to illustrate key events. The camera would freely fly across oceans as it observes evolutionary responses to changes in the Earth's climate and geography in accelerated time. Ice ages, plate tectonics, creation and removal of evolutionary niches..such a show in one artistic movement could do what no amount of words on the subject ever could. I imagine it playing with no narration only a sound track, it's a thought anyway...maybe someone will come along and do something like it.

Other Comments by sent2null

42. Comment #115861 by nathan_forst on January 24, 2008 at 11:56 pm

A couple of years ago I read Stephen Baxter's Evolution, where he illustrates a future earth devoid of human habitation. This future earth, just like previous years of Earth's evolution had rodents and primates competing for resources. In this book the rodents won out and given time evolved into many different species. This article reminds me of that book.

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