t embroidered—walcott makes nomention of a slipping horse or falling snow—but there is no disputing that it was anextraordinary find。
it is almost impossible for us whose time on earth is limited to a breezy few decades toappreciate how remote in time from us the cambrian outburst was。 if you could fly backwardsinto the past at the rate of one year per second； it would take you about half an hour to reachthe time of christ； and a little over three weeks to get back to the beginnings of human life。
but it would take you twenty years to reach the dawn of the cambrian period。 it was； in otherwords； an extremely long time ago； and the world was a very different place。
for one thing； 500…million…plus years ago when the burgess shale was formed it wasn’t atthe top of a mountain but at the foot of one。 specifically it was a shallow ocean basin at thebottom of a steep cliff。 the seas of that time teemed with life； but normally the animals left norecord because they were soft…bodied and decayed upon dying。 but at burgess the cliffcollapsed； and the creatures below； entombed in a mudslide； were pressed like flowers in abook； their features preserved in wondrous detail。
in annual summer trips from 1910 to 1925 （by which time he was seventy…five years old）；walcott excavated tens of thousands of specimens （gould says 80；000； the normallyunimpeachable fact checkers of national georgraphic say 60；000）； which he brought back towashington for further study。 in both sheer numbers and diversity the collection wasunparalleled。 some of the burgess fossils had shells； many others did not。 some were sighted；others blind。 the variety was enormous； consisting of 140 species by one count。 “the burgessshale included a range of disparity in anatomical designs never again equaled； and notmatched today by all the creatures in the world’s oceans；” gould wrote。
unfortunately； according to gould； walcott failed to discern the significance of what hehad found。 “snatching defeat from the jaws of victory；” gould wrote in another work； eightlittle piggies； “walcott then proceeded to misinterpret these magnificent fossils in the deepestpossible way。” he placed them into modern groups； making them ancestral to today’s worms；jellyfish； and other creatures； and thus failed to appreciate their distinctness。 “under such aninterpretation；” gould sighed； “life began in primordial simplicity and moved inexorably；predictably onward to more and better。”
walcott died in 1927 and the burgess fossils were largely forgotten。 for nearly half acentury they stayed shut away in drawers in the american museum of natural history inwashington； seldom consulted and never questioned。 then in 1973 a graduate student fromcambridge university named simon conway morris paid a visit to the collection。 he wasastonished by what he found。 the fossils were far more varied and magnificent than walcotthad indicated in his writings。 in taxonomy the category that describes the basic body plans ofall organisms is the phylum； and here； conway morris concluded； were drawer after drawer ofsuch anatomical singularities—all amazingly and unaccountably unrecognized by the manwho had found them。
with his supervisor； harry whittington； and fellow graduate student derek briggs； conwaymorris spent the next several years making a systematic revision of the entire collection； andcranking out one exciting monograph after another as discovery piled upon discovery。 manyof the creatures employed body plans that were not simply unlike anything seen before orsince； but were bizarrely different。 one； opabinia； had five eyes and a nozzle…like snout withclaws on the end。 another； a disc…shaped being called peytoia； looked almost ically like apineapple slice。 a third had evidently tottered about on rows of stilt…like legs； and was so oddthat they named it hallucigenia。 there was so much unrecognized novelty in the collectionthat at one point upon opening a new drawer conway morris famously was heard to mutter；“oh fuck； not another phylum。”
the english team’s revisions showed that the cambrian had been a time of unparalleledinnovation and experimentation in body designs。 for almost four billion years life haddawdled along without any detectable ambitions in the direction of plexity； and thensuddenly； in the space of just five or ten million years； it had created all the basic bodydesigns still in use today。 name a creature； from a nematode worm to cameron diaz； and theyall use architecture first created in the cambrian party。
what was most surprising； however； was that there were so many body designs that hadfailed to make the cut； so to speak； and left no descendants。 altogether； according to gould； atleast fifteen and perhaps as many as twenty of the burgess animals belonged to no recognizedphylum。 （the number soon grew in some popular accounts to as many as one hundred—farmore than the cambridge scientists ever actually claimed。） “the history of life；” wrote gould；“is a story of massive removal followed by differentiation within a few surviving stocks； notthe conventional tale of steadily increasing excellence； plexity； and diversity。”
evolutionary success； it appeared； was a lottery。
one creature thatdid manage to slip through； a small wormlike being called pikaiagracilens； was found to have a primitive spinal column； making it the earliest known ancestorof all later vertebrates； including us。pikaia were by no means abundant among the burgessfossils； so goodness knows how close they may have e to extinction。 gould； in a famousquotation； leaves no doubt that he sees our lineal success as a fortunate fluke： “wind back thetape of life to the early days of the burgess shale； let it play again from an identical startingpoint； and the chance bees vanishingly small that anything like human intelligence wouldgrace the replay。”
gould’s book was published in 1989 to general critical acclaim and was a great mercialsuccess。 what wasn’t generally known was that many scientists didn’t agree with gould’sconclusions at all； and that it was all soon to get very ugly。 in the context of the cambrian；“explosion” would soon have more to do with modern tempers than ancient physiologicalfacts。
in fact； we now know； plex organisms existed at least a hundred million years beforethe cambrian。 we should have known a whole lot sooner。 nearly forty years after walcottmade his discovery in canada； on the other side of the planet in australia； a young geologistnamed reginald sprigg found something even older and in its way just as remarkable。
in 1946 sprigg was a young assistant government geologist for the state of south australiawhen he was sent to make a survey of abandoned mines in the ediacaran hills of the flindersrange； an expanse of baking outback some three hundred miles north of adelaide。 the ideawas to see if there were any old mines that might be profitably reworked using newertechnologies； so he wasn’t studying surface rocks at all； still less fossils。 but one day whileeating his lunch； sprigg idly overturned a hunk of sandstone and was surprised—to put itmildly—to see that the rock’s surface was covered in delicate fossils； rather like theimpressions leaves make in mud。 these rocks predated the cambrian explosion。 he waslooking at the dawn of visible life。
sprigg submitted a paper to nature ； but it was turned down。 he read it instead at the nextannual meeting of the australian and new zealand association for the advancement ofscience； but it failed to find favor with the association’s head； who said the ediacaran imprints were merely “fortuitous inorganic markings”—patterns made by wind or rain ortides； but not living beings。 his hopes not yet entirely crushed； sprigg traveled to london andpresented his findings to the 1948 international geological congress； but failed to exciteeither interest or belief。 finally； for want of a better outlet； he published his findings in thetransactions of the royal society of south australia。 then he quit his government job andtook up oil exploration。
nine years later； in 1957； a schoolboy named john mason； while walking throughcharnwood forest in the english midlands； found a rock with a strange fossil in it； similar toa modern sea pen and exactly like some of the specimens sprigg had found and been trying totell everyone about ever since。 the schoolboy turned it in to a paleontologist at the universityof leicester； who identified it at once as precambrian。 young mason got his picture in thepapers and was treated as a precocious hero； he still is in many books。 the specimen wasnamed in his honor chamia masoni。
today some of sprigg’s original ediacaran specimens； along with many of the other fifteenhundred specimens that have been found throughout the flinders range since that time； canbe seen in a glass case in an upstairs room of the stout and lovely south australian museumin adelaide； but they don’t attract a great deal of attention。 the delicately etched patterns arerather faint and not terribly arresting to the untrained eye。 they are mostly small and disc…shaped； with occasional； vague trailing ribbons。 fortey has described them as “soft…bodiedoddities。”
there is still very little agreement about what th