The ray - fin fish class includes 98 percent of live fishes . However , 400 million years ago , beam - finned fishes were rare , making the few Devonian earned run average fogy we have more interesting than those from fishes that became evolutionary stagnant - end . In this context , an exceptionally well - preserved example of a previously unknown 380 - million - twelvemonth - old ray - finned Pisces is a precious discovery .
Dr Brian Chooof Flinders University and colleagues name the newly identify fishPickeringius acanthophorus . It ’s only the third Devonian shaft of light - finned Pisces the Fishes where we have a three - dimensional souvenir of its braincase . Choo narrate IFLScience that intact brain cases help build specie household trees . ” Einstein cases change much more lento than other consistency parts , ” he said .
Pickeringiusalso has a highly classifiable feature film , Choo describe inPapers in Palaeontology . Many Devonian Era fishes had openings call spiracles on the top of their head , butPickeringius ' are much larger than any we have find oneself on its contemporaries – up to a fifth the skull ’s distance .
Today , African bichirs use similar possibility to breathe air when the swampland in which they live become low on oxygen . Modern rays use them when their gills are pressed against the sea floor . Choo tell IFLScience neither function appears utile for what look like a mid - depth fish , so their purpose remains a mystery story , although Choo speculated they might have been ready to hand if trapped in a rockpool wait for high lunar time period .
The Pisces also carried spikes all over its eubstance , some of which had sidelong barbs for surplus protection against the era ’s fearsome predators .
The Gogo Formation is among the most noteworthy fogey sites in the universe . Most fossils , particularly former ones , from other website are incomplete and have been squash flat . Gogo , however , is one of a very little number of places where we find such ancient intact three - dimensional specimens . Many Gogo fogy are so well carry on , they are referred to as “ float in Harlan Stone ” .
This conservation occurred , Choo explicate , because during the Devonian there was a thriving Witwatersrand off the coast of Western Australia next to a outrageous dip - off into mysterious piddle . “ There were no frigid ice caps at the meter to drive sea circulation , ” Choo said .
As a result , the deep oceans had much less atomic number 8 than they do today , which prevent the scavenging of fish that sank into deep waters . anaerobiotic bacteria consume the fish ' flesh , but before the bones could decay , they became protect by a shell of calcium carbonate , which eventually became a nodule of limestone . When fossilist separate these nodules undecided , they are often repay with beautifully preserved mintage , in a fashion we do n’t see from epoch when abstruse waters had enough oxygen to abide more aliveness . Pickeringiusis the 5th beam - fin species we ’ve constitute at Gogo .
