Biggest rodent ever, new research


This video says about itself:

22 April 2010

CC en Español

A short animated video about the largest rodent that ever lived, Josephoartigasia monesi, also known as the Giant Pacarana. A fossil skull discovered in Uruguay belonged to a rodent, which researchers estimate weighed up to 1 tonne (1000kg)! Andrés Rinderknecht and R. Ernesto Blanco named the new species “monesi” in honor of the famous paleontologist, Alvaro Mones.

The largest rodent alive today is the capybara, which can weigh over 60kg, much smaller than its extinct cousin.

The original article describing J. monesi can be read here.

The skull is housed in Montevideo, Uruguay in the Museum of Natural History and Anthropology.

Much thanks to Dr. Blanco and Dr. Rinderknecht for their amazing discovery! And thank you to Luisa for her Spanish translation…I owe you one!

From daily The Independent in Britain:

Biggest ever rodent was a huge guinea pig with strong, tusk-like teeth

Bite was about as strong as that of a tiger

Andrew Griffin

Wednesday 04 February 2015

The biggest rodent that ever lived, which looked like a huge guinea pig and used its big teeth like an elephant does its tusk, according to new research.

Josephoartigasia monesi, which lived about three million years ago, is the biggest fossil rodent ever found.

Computer modelling has been used to determine how powerful its bite was, and how it used its huge teeth. The research was led by Philip Cox, of the University of York’s Centre for Anatomical and Human Sciences.

He found that the bite forces were similar to that of a tiger — about 1400 Newtons. The teeth would have been able to withstand three times that force.

“We concluded that Josephoartigasia must have used its incisors for activities other than biting, such as digging in the ground for food, or defending itself from predators,” said Cox. “This is very similar to how a modern day elephant uses its tusks.”

To conduct the research, Cox made a CT scan of the fossil and used it to reconstruct its skull. Researchers then used finite element analysis on the model, a technique that can be used to predict how an object would undergo stress and strain.

Costa Rica 3-Uruguay 1, congratulations with bird videos


This video is about a male resplendent quetzal in the Savegre valley in Costa Rica.

Like favourites and reigning football world champions Spain lost 1-5 to the Netherlands: tonight underdogs Costa Rica won unexpectedly 3-1 against Uruguay. Uruguay had won the World Cup twice, and was #4 at the last World Cup.

To congratulate Costa Rica, here are three videos, one per goal, about the beautiful birds in Costa Rica.

This video is called Amazing hummingbirds – Costa Rica.

And this video is called Toucans of Costa Rica.

Talking about wildlife in Costa Rica: there will be more of my reports about it, but sorting out photos took longer than expected. But Costa Rican wildlife reports will be back at this blog.

Uruguayan dictatorship torture general on trial


This video says about itself:

May 28, 2010

Tens of thousands of Uruguayans including President Jose Mujica marched in silence on May 20th demanding to know the fate of victims of the US-backed military dictatorship which led the country from 1973 to 1985.

From daily The Morning Star in Britain:

Dictatorship general appeals jail sentence

Friday 10 May 2013

The first general convicted of human rights violations during Uruguay’s dictatorship has appealed his 28-year prison sentence, his lawyer has confirmed.

General Miguel Dalmao was found guilty on Wednesday of the 1974 murder of literature professor and communist activist Nibia Sabalsagaray.

Nibia Sabalsagaray

Gen Dalmao’s lawyer dismissed the verdict as “speculation” and said he’d already launched an appeal on Thursday.

Uruguay’s military junta had previously accepted his claim that 24-year-old Ms Sabalsagaray hanged herself with a handkerchief from an iron peg in the wall just four inches above her head.

Her family were banned from seeing her body but a medical student reported signs of torture and inconsistencies with suicide.

Gen Dalmao has been in hospital for months and is unlikely to serve his sentence.

Pre-dinosaur mesosaurs’ live birth


Despite the fact that the mesosaur embryos were dated to around 280 million years ago, researchers found them in a remarkably well preserved condition

From Discovery News:

Live Birth Predates Dinos

Analysis by Jennifer Viegas

Mon Dec 10, 2012 06:31 AM ET

Producing living young, and not external eggs, is a form of birth that could date back to 280 million years ago or even earlier, a new study suggests.

Called viviparity, this form of birth is used by humans, but clearly we were far from being the first to evolve it.

The study, published in the December issue of Historical Biology: An International Journal of Paleobiology, focuses on mesosaurs, which were among the world’s first aquatic reptiles. They lived in what are now South America and South Africa at a time when these two landmasses were united and part of the giant supercontinent Pangaea.

Mesosaurs, and even their earlier ancestors, possibly “were not able to produce hard shelled eggs, at least for the first several million years of their evolution,” lead author Graciela Piñeiro, a paleontologist at Uruguay‘s Facultad de Ciencias, told Discovery News. “After the recent discovery of mesosaur embryos, we can state with a high degree of confidence that embryo retention developed early in amniote evolution, given that mesosaurs are among the basal-most reptiles and that they date from the Early Permian around 280 million years ago.”

Piñeiro and colleagues Jorge Ferigolo, Melitta Meneghel and Michel Laurin recently discovered the exceptionally well-preserved mesosaur embryos at sites in Uruguay and Brazil. The environmental conditions at the locations allowed for the preservation of soft tissues, nerves and blood vessels, she said.

Giving birth in this manner and laying eggs each come with advantages and disadvantages. Eggs with hard, mineralized shells, such as those associated with today’s chicken eggs or those of dinosaurs, are believed to help reproduction on dry land. But many terrestrial animals, including humans, do not lay eggs, so there must be other benefits to viviparity.

“We think that the retention of the eggs may have appeared in amniotes as a useful strategy to avoid predation and increase survivorship chances for the embryos,” Piñeiro said.

Parental care often then follows. There is even some evidence that mesosaurs provided such care, because adults and juveniles have been associated together in the fossil record.

At least some mesosaurs even had the added challenge of giving birth and raising young in extremely salty water.

“In Uruguay, mesosaurs may have first colonized the shallow water environment of the Mangrullo Formation, which under the establishment of arid climatic conditions that increased evaporation became like a salty marsh where just a few opportunistic organisms could tolerate the anoxic bottom conditions generated by the accumulation of high amounts of organic matter,” Piñeiro explained.

When infant mesosaurs entered the world, they possibly even had a salt gland and other anatomical adaptations already in place, allowing them to survive the otherwise challenging conditions.

There is also compelling evidence that giant, carnivorous, four-flippered reptiles known as plesiosaurs gave birth to live young as well. Robin O’Keefe of Marshall University and team discovered a big embryonic marine reptile contained in the fossil of its 15.4-foot-long mother, which lived 78 million years ago.

“The embryo is very large in comparison to the mother,” O’Keefe said, “much larger than one would expect in comparison with other reptiles. Many of the animals alive today that give birth to large, single young are social and have maternal care. We speculate that plesiosaurs may have exhibited similar behaviors, making their social lives more similar to those of modern dolphins than other reptiles.”

Migratory bird conservation in Uruguay


This video is from the Laguna da Rocha in Uruguay.

From BirdLife:

Southern Cone Grasslands Alliance activities support shorebird conservation in Uruguay

Wed, Apr 11, 2012

Annually, Buff-breasted Sandpiper Tryngites subruficollis and American Golden Plover Pluvialis dominica undertake some of the longest journeys of any migratory birds in the world, from their breeding grounds in the tundra of North America (Canada and Alaska) to wintering sites in the grasslands of Southern South America. Aves Uruguay (BirdLife in Uruguay) and partners have secured approximately 3000 hectares for both species of shorebirds through good management practices of the natural grasslands.

Both species have suffered significant population declines due to habitat loss on their migration and wintering grounds and through hunting (in the Caribbean, and historically in North and South America). Their primary wintering grounds are the Southern Cone or Pampas grasslands of South America, and Laguna de Rocha in Uruguay is one of the few sites globally where they can be found in large numbers on a regular basis.

Were prehistoric mesosaurs viviparous?


This is a Brazilian video on a mesosaur discovery.

From Huffington Post in the USA:

Fossil Suggests Prehistoric Reptile Birthed Live Young

Posted: 04/ 5/2012 7:49 am Updated: 04/ 5/2012 7:49 am

Fossilized embryos unearthed recently in South America are having a big impact on paleontologists’ ideas about prehistoric reptiles’ way of life.

The little fossils suggest that some reptiles could have been “viviparous,” meaning that instead of laying eggs, they gave birth to live young.

The fossils are what’s left of aquatic reptiles that lived about 280 million years ago—prehistoric animals that scientists call mesosaurs, not to be confused with mosasaurs, which were also a marine reptile.

One of the fossils, found in Brazil, preserves of a baby mesosaur still inside its mother. Another fossil, unearthed in Uruguay, shows an embryo not inside a mother but on its own.

The finds were described in the March issue of the journal Historic Biology.

“I received a big shock when I realized that what I had collected was indeed a very small, curled mesosaur, the smallest I have seen ever,” study co-author Dr. Graciela Piñeiro, associate professor of paleontology at Facultad de Ciencias told USA Today by e-mail about the Uruguayan fossil. She said it was “exquisitely preserved.”

Researchers said in the study they also found at least 26 small bones, believed to be late embryos, and larger mesosaur skeletons.

Just last year, scientists reported that “whale-like” marine reptiles, plesiosaurs, birthed live young. The report came after the fossil of a pregnant plesiosaur was analyzed.