Around 125 million year ago , an early mammal was scamper around a wetland in what is now key Spain . Unfortunately for this slight furred creature , it receive its end in the weak depths and was quickly buried by fine sediment . In 2011 , a team of scientist found the animal preserved in astonishing detail in the rocks of the Las Hoyas Quarry .
“ Well the fossil itself is a prominent find , ” University of Chicago ’s Zhe - Xi Luo , who co - author the study describing the fossil published inNature , told IFLScience . “ When I first saw the original fogy in Madrid , it was absolutely dumfounding . The self-aggrandising revelations started to trickle in when scanning negatron microscope outcome bulge out coming in . We realized first that this mammal has compound hair . ”
This was the first of manyincredible detailspreserved in the fossil . The researchers were able-bodied to see individual pores and even follicles – the tiny tegument organ that bring forth hair . A compound hair follicle , where one pore create a single primary hair and other small lowly hairs , is a basic anatomical structure of mammalian pilus . And it seems that this lineament acquire early in the mammal lineage .
“ The second lineament that is awe-inspiring is that the spines are also clustered , ” says Luo . We know from modern mammals that it take multiple whisker follicle to fuse together during the early stages of embryonic ontogeny to farm prominent back . These exquisitely preserved microstructures now show , according to Luo , “ that this 125 - million - yr fossil in reality has the same design in embryogenesis of this hair like structure . ”
The little critter , calledSpinolestes xenarthrosus , would have subsist scurry around the feet of the dinosaurs that dominated the watery landscape at the time , while early birds submit to the sky . It is a phallus of a now out mathematical group of mammals called “ eutriconodonts , ” which on the evolutionary tree of mammal devolve between the egg-laying mammal ( testis - lay mammal like platypuses and echidna ) , and the therians ( pouched mammal and all other mammal ) .
With such high levels of saving , research worker can now once and for all say that complex structural features such as compound hair follicles and spines , many of which are fundamental mammalian characteristic , were already well established during the age of the dinosaurs , some 125 million class ago .
Top look-alike in text : A reconstructive memory of what the mammal might have looked like in veridical animation . Oscar Sanisidro
Bottom image in schoolbook : The actual fossil of S. xenarthrosus . Georg Oleschinski
