grit dredging off the coast of Java has recovered more than 6,000 bones , including two fragments of skulls of the early humansHomo erectus . H. erectusand the other animals get there lived on dominion long since eat up by the ocean . The finds rebut the idea that other human were isolated on Indonesian islands , show they were often connected when low - lying areas were dry .
At the apex of recent ice ages , the island of Indonesia and Australia were link intothree landmasses , with only a few deep channels separate them . We see the legacy of this in these island ’ animals and plant . Those that were once connected to mainland Asia through what is bang as Sundaland apportion common species , very different from those that were plug in to Australia instead .
The Madura Strait , between Java and Madura , was part of Sundaland several prison term during the cold office of the ice ages , so when dredging occurred there , the fossils it captured admit the fauna of the epoch .
Java is central to what we make love aboutH. erectus , arguably the most successful human mintage , having survived for2 million years . All fossil specie have a “ type specimen ” used for the initial scientific description , and in the casing ofH. erectus , this is live as Java Man . At one clock time , the entire mintage was come to to under that name , but we now screw they were the first humankind to inhabit most of Eurasia .
It was long recall , however , thatH. erectuswas insulate for most of its time on Java , unable to cross the straits to nearby island . There ’s been some pushback to that withrecent studiesraising the hypothesis that early human ’ sailplaning skillsmight have been underestimate .
However , twoH. erectusskull shard found in the Madura Strait dredging propose the populations of what are now island may have been able to interact without getting their feet wet .
The dredging was carry on in what would have been the vale of the Solo River when glacier interlace up much of the sea , lowering their levels by around 100 meters ( 328 foot ) . River guts washed down from the Javan highlands turned bones in the deltas into fossils , and already , leftover of 36 species have been found in the dredge George Sand .
Some of the richest source ofH. erectusfossils in the humankind , include 11 fond skull , come from the hold up parts of the Solo valley , including theyoungest specimen from Java , around 112,000 years ago . The original Java Man skull fragment also comes from the area , but before the river had organize .
Such a localisation , where a river meet the glide , would have been particularly attractive to the early humans . " Here they had water , shellfish , fish , edible plants , seeds and fruit all class round , " Leiden University Ph.D. student Harry Berghuis said in astatement . " We already knew thatHomo erectuscollected river shells . Among our new uncovering are issue marker on the bones of water turtles and tumid numbers of low bovid bones , which point to hunt and consumption of bone marrow . "
The skull date from 140,000 age ago , the 2d last top glaciation , a point in time whereH. erectuswas no longer the only human species in the region . Not only were there hobbits ( Homofloresiensis ) of Flores , but Denisovans , more closely come to to innovative human race , may have been in the area , possibly even interbreedingwith the earlier arrivers .
The phone number of bovid bones , and the marks on them , indicate they were hunted byH. erectus , not just scavenged when weak . " We did n’t notice this in the earlierHomo erectuspopulation on Java , but do know it from more modern human species of the Asian mainland . Homo erectusmay have copied this practice from these populations , ” Berghuis tell . “ This indicate there may have been inter-group communication between these hominin groups , or even genetic exchange . "
Sundaland , at the time , would have most closely resembled the current African savannah , with many alike mintage inhabit it .
The treasure - trove of fossils find in the dredging is now on display at the Geological Museum in Bandung , Indonesia , marking an insight into other human lifestyle that ca n’t be examine anywhere else .
The study is open access inQuaternary Environments and Humans .
