Post date: Dec 27, 2012 1:55:26 PM
Hungarian scientists discover ancient fossils of a new giant lizard species that lived in freshwater. A reconstruction of the 'mosasaur' has gone on display in the Hungarian Natural History Museum as the palaeontologists published their findings.
BUDAPEST, HUNGARY (DECEMBER 21, 2012) (REUTERS) - Hungarian palaeontologists have found evidence of a new freshwater species of 'mosasaur', an ancient lizard that lived during the Late Cretaceous period 84 million years ago.
Mosasauroids are conventionally conceived of as gigantic, aquatic marine lizards with a distribution in the Late Cretaceous (90-65 million years ago) oceans and seas of the world.In a recent publication, the Hungarian and Canadian joint research team published a report on the fossilized remains of numerous individuals (small juveniles to large adults) of a new taxon, Pannoniasaurus inexpectatus that represent the first known mosasauroid that lived in freshwater environments.
The palaeontologists realized in 2004 that their findings revealed a new mosasaur, but they needed to find other remains of the fossil apart from the vertebrae. Later on skull and lower jaw elements confirmed their findings that were published last week.
"These are those vertebrae which are very very abundant at the locality, actually those are the most frequent remains of this mosasaur. It's quite characteristic because it's very primitive in its characters. You can see that the body of the vertebrae is quite V-shaped and it has this precondylar constriction, I mean the condyle is wider than the centrum itself, which is unique among mosasaurs, only Pannoniasaurus has this character," said palaeontologist of the Hungarian Natural History Museum, Laszlo Makadi.
A reconstruction of the new species is already on display in the Museum. The fossils were recovered from a waste dump of a coal mining operation in Iharkut, in western Hungary. The researchers unearthed thousands of fossils from several individuals, ranging in size from 3 to 13 feet. The smaller fossils most likely belonged to juvenile mosasaurs, scientists said. Fossils of the mosasaur Plioplatecarpus were recovered from freshwater sediments in Canada, but the lack of related finds suggests a random occurrence with no ecological implications.
"We have found specimens ranging from 70 centimetres to 6 meters but probably the most abundant size was around 3 or 4 meters. This is one main point, one main evidence of these mosasaurs living here in this freshwater environment because you see... actually you can see some very young juveniles, you can see a bit more adults and then you can see quite large adults living here which means there was a complete population living in these environments instead of just for example adults swimming up in the rivers to mate or for some other reasons," Makadi said.
Mosasaurs, unlike dinosaurs, were true lizards, meaning they were able to dislocate their jaw at will and swallow anything they could get their mouths around.
"There are a lot of different sizes ... I have, I don't know for example cervical vertebrae of a size of 1 cm which belonged to this very small juveniles, and then I can see a bit larger ones and even larger ones, and even larger ones, so I would say that probably these remains originate from dozens of individuals," Makadi said.
Other fossils recovered at the site showed that these freshwater rivers were also inhabited by fish, amphibians, turtles, lizards, crocodiles, and dinosaurs.
Hungarian palaeontologists are hopeful they will find more new fossils at Iharkut in the future. Their research has been supported by the Hungarian National Scientific Fund, the Hungarian National Academy of Sciences 'Lendület' Program, the NSERC Discovery Grant and a University of Alberta, Chairs Research Allowance.