New fossil specimens of the big land turtle to have ever lived are cave in up more of its secrets , revealing trade name new insights into these giants that swan Earth 8 million old age ago .
The new specimens found in northerly Venezuela and , for the first prison term , Colombia expands its range across South America , suggests a shape of sexual dimorphism not view before in any side - necked turtle , and admit the big carapace ( upper shell ) discovered yet .
First described in the 1970s , Stupendemys geographicuswas one of themany behemothsfound in tropic South America 5 - 10 million days ago . The region would have been warm , humid , and swampy ; everlasting for a range of megafauna that included giant crocodiles , alligators , caimans , and gavialis . Though it was likely feed on by these , its own size is not to be sniffed at .
Reporting inScience Advances , researchers have psychoanalyse several new shell – as well as the first - ever lower jaw – let in the largestS. geographicuscarapace ever found at 2.4 beat long ( 7.8 substructure ) . Based on this , the researcher guess the hefty turtle weigh around 1,145 kilograms ( 2,520 pounds ) , 100 sentence that of its closest living relative , thebig - headed Amazon river turtle . This makes it the declamatory land polo-neck we know of , and rivals the renowned Late Cretacious shipboard soldier turtleArchelonin size of it .
“ Stupendemysis for sure the enceinte recordedside - make out turtle , one of the two kinds of turtles there are , ” Professor Marcelo Sánchez , music director of the Paleontological Institute and Museum of UZH and straits of the study , distinguish IFLScience . “ In the other radical , the Cryptodira , Archelonis the biggest , a marine turtle . Archelonis the largest turtle there has been based on available specimens , butStupendemyswas very nigh . ”
The first uncovering ofStupendemysat the La Venta archaeological website in the Tatacoa Desert of Colombia , and substantiation that specimen previously thought to be another coinage found in Brazil are in factStupendemys , hugely expand the turtleneck ’s ambit to include the whole northern part of South America . The researchers also think this shows thatS. geographicuswas probably the only jumbo turtle roaming the northern Neotropics during the Late Miocene .
Perhaps , most excitingly of all , the researchers discovered odd conflict in some of the shells . Some of them had horn - similar racing shell at the front of the shield . The squad opine this bespeak sexual dimorphism in the coinage , rather than more than one mintage ; the male had horns , possibly to protect their massive head when hire in scrap with other males , while the females had none . It ’s the first time French horn have been found as a form of sexual dimorphism in any side - necked turtles .
“ This variety of dimorphism is indeed peculiar in that horns in a carapace are very rarified , ” Sánchez tell IFLScience . “ One could then question if indeed we have two species rather of two sexes , but everything speaks for two sex . “
This tropic region of South America is famed for its extinct megafauna . What was once quick , extensive wetlands and fresh water lakes bring home the bacon a habitat that supported predators and quarry . The investigator conceive this ecosystem would have allow for the turtle to get so big , but it may have also been influenced by the bigger , toothier creatures that also inhabited the surface area . They found raciness marks on some of the carapaces , and in one case , even a tooth , that they consider came from one of the giant crocodilians of the time – potentially aPurussaurus , the largest cayman at 13 metre ( 43 feet ) .
We would n’t desire to meet anything that could take on a 3 - meter ( 9.8 - foot ) armored turtle .
