A few years ago various corners of the Internet bonk to ask whether someone would rather struggle ahorseback - sized duck or a hundred duck - sized horses . Perhaps those ask knew Australia was in fact once home to a duck relation that librate as much as a large horse . Anyone take the merits of fightingDromornis stirtoni(our suggestion , do n’t ) might be peculiar to know of their potential opponent ’s intellectual capacity . Thankfully , result are at hand .
The eight know coinage of the mihirung family – an primordial term for " giant razz " – left no fossilized wit for us to analyse , but we have found a sampling of skull . Dr Warren Handleyof Australia ’s Flinders University has examined these and found them unusually revealing as to the shape of the brain inside . Since the localisation of mind regions devoted to different roles is fairly well conserve across brute species , there is much to memorise from knowing where the self-aggrandizing chip of mihirungs ' brain were . Combining this with observation about other parts of the “ demon duck of doom ” , such as the size of it and position of its eye socket , has proven revealing .
In the journalsDiversity , Handley andDr Trevor Worthydescribe the mihirung as experience ; “ A relatively large cerebellum and associated hindbrain . ”
“ Together with their large , forward - confront eyes and very expectant bills , the human body of their mental capacity and nerves paint a picture these birds likely had well - developed stereoscopic vision , or depth perception , and fed on a diet of soft leaves and fruit , ” Handley said in astatement . “ The shape of their brains and nerve have severalise us a lot about their centripetal capabilities , and something about their potential lifestyle which enable these remarkable birds to survive in the forests around river channels and lake across Australia for an extremely tenacious clock time . ”
Gastroliths – Harlan Fiske Stone many birds employ to smash down food – happen with some fossil confirm the nature of their diet . The location at which their bone have been found show the later mihirungs at least never venture far from waterway .
The mihirungs survived from around 24 million years ago until around 50,000 years ago . The largest , and last surviving , D. stirtoni , grew to 3 meter ( 10 feet ) marvellous with males weighing 600 kilogram ( 1,300 pounds ) . Although some estimates make Madagascar ’s elephant snort declamatory still , Handley told IFLScience that using ordered technique to estimate weight , these were the heavy raspberry ever to shake the Earth .
Once thought to have been flightless bird , a group that includes ostriches andcassowaries , mihirungs are now count part of the chicken and duck family , a find Handley ’s subject area confirms . As with the other majuscule beasts of the Pleistocene , the cause of the mihirungs ' demise ishotly debate , but Handley tell IFLScience human arriver in Australia definitely bestow
For most of their fourth dimension , adult mihirungs had no predators . They did n’t get so big to debar being eaten .
Instead , Handley say IFLScience they were a mathematical product of the phenomenon where some herbivores respond to a poor dieting by becoming massive . Only through size of it could they get enough of the low nutrition food available to them to survive , and being so tall at least let them shop on fresh leaves . “ Sexual selectionwould also have lend , ” Handley add , with the largest males winning competitiveness to mate .
