The age of dinosaur on land was also the geological era of pterosaurs in the sky - but part way of life through a strange modification happened , with toothless species replace toothed ones as the dominant flying creatures .
Despite their number and diversity , we are only starting to hear about pterosaurs , as their thin bones did not fossilize well . It was only this twelvemonth that enough of their bollock have been establish to assist us start tounderstand their breeding .
However , we do know that until 90 million year ago the dominant pterosaurs ( Ornithocheiridae ) had teeth . From the late Cretaceous all the dodo we have are toothless , predominantly penis of the Azhdarchidae kin ( from the Persian for flying dragon ) .
InZooKeysDrAlexander Averianovof the Russian Academy of Sciences has bring out aReview of taxonomy , geographic distribution , and paleoenvironments of Azhdarchidae , investigating the 51 known specimens ( often just a few bones ) and three preserved tracks .
found on the multifariousness of geologic site where the bones have been recover Averianov concludes , “ Azhdarchids likely inhabited a change of surroundings , but were abundant near large lakes and rivers and most unwashed in nearshore marine paleoenvironments . ”
The reason the Ornithocheiridae died out is “ still poorly understood ” concord to Averianov , but “ apparently reflects some fundamental changes in Cretaceous ecosystems . ” This change appear to have been associated with a surge in C dioxide levels . at the same time , crustal production reach its high rate for 100 million year and the Earth ’s oceansbecame deprived of atomic number 8 . In combination these wiped out a fourth of the microscopic sea creatures at the base of the intellectual nourishment string .
However , it is not clear why these dramatic outcome would pass over out notched pterosaur , leave behind room for toothless species to flourish . The transition did nothing to fall the size of these terrible brute with some of the late Azhdarchidae experience 12 meter wingspan .
ZooKeys . Although their off-white fossilize poorly , Azhdarchidae remains have been found around the world , indicating how widespread they were in the late Cretaceous .
H / TLiveScience
