Dig­ging into planet’s his­tory reaps re­wards

The Press - - Catalyst - David Von Drehle

News of a marvel took me to the palaeon­tol­ogy labs of the Univer­sity of Kansas re­cently. There I found my­self look­ing at the fos­silised bones of an an­cient pad­dle­fish.

What had me thun­der­struck were the tiny beads of glass caught in its gill rak­ers, which sug­gest that the crea­ture per­ished while gasp­ing for air as fire rained from the sky.

The com­po­si­tion of those beads, or tek­tites, fur­ther sug­gests that they were formed when a mas­sive as­ter­oid slammed into the Earth with the force of 10 bil­lion Hiroshi­mas and ended the Cre­ta­ceous pe­riod.

In other words, I was look­ing at a record­ing in rock of the mo­ment when life nearly ended on Earth, ar­guably the big­gest sin­gle event in our planet’s liv­ing his­tory.

This fish is one of a trove of fos­sils dis­cov­ered by Univer­sity of Kansas grad­u­ate stu­dent Robert DePalma at a site in North Dakota. Should the site prove to con­tain all that DePalma claims, it is among the most im­por­tant finds in his­tory.

DePalma’s the­sis ad­viser, David Burn­ham, showed me the fish and other arte­facts en­tombed in the fall­out from the so-called Tanis site. A dec­o­rated vet­eran of the academic bat­tle­field, Burn­ham ap­peared un­wor­ried that some sci­en­tists have ex­pressed doubts about the ex­trav­a­gant claims.

‘‘We will be mak­ing the case in a num­ber of pa­pers over the next few years, and peo­ple will see what we’ve found,’’ said Burn­ham.

It’s all there, he as­sured me: ev­i­dence of cat­a­strophic flood­ing un­leashed by seis­mic waves, of pul­verised bedrock fall­ing like hail, of forests burn­ing in a world­wide con­fla­gra­tion, of early mam­mals hud­dling in their bur­rows as dinosaurs died above­ground. He re­it­er­ated that

sci­en­tists will be un­pack­ing the trea­sures of Tanis for a half­cen­tury.

One of the as­ton­ish­ments of these times is just how large a half-cen­tury has be­come. A young palaeon­tol­o­gist work­ing the same sparse land 50 years ago could have un­earthed this fos­sil bed with­out the knowledge nec­es­sary to read its amaz­ing story.

The Apollo mis­sions to the moon had just awak­ened the sci­en­tific com­mu­nity to the idea of space as a sort of shoot­ing gallery in which the Earth was the tar­get of fre­quent in­com­ing shots.

The fa­ther-and-son team of Luis and Wal­ter Al­varez had not yet ar­gued that a band of ash heavy in irid­ium, a rare metal found in space de­bris, had coated the Earth roughly 65 mil­lion years ago (sci­ence would later nar­row the date to about 66 mil­lion years ago).

Alan Hilde­brand and Wil­liam Boyn­ton had not yet pin­pointed the Chicx­u­lub crater in what is now the Yu­catan Penin­sula as the im­pact site of a gi­ant as­ter­oid or comet.

In­deed, only in 2010 did a panel of sci­en­tists weigh in to say, based on core sam­ples of the crater, that an im­pact some

66 mil­lion years ago sent shock waves through the planet, rain­ing fire and coat­ing the Earth in ash. This catastrophe marked the end of the age of dinosaurs, ex­tin­guish­ing some

95 per cent of all species and clear­ing the way for the rise of mam­mals.

It’s all part of the ad­vance of sci­ence, which has ac­cel­er­ated from a march to a gal­lop. Tech­nol­ogy and glob­al­i­sa­tion may rat­tle economies and in­flame politics, but they are as­ton­ish­ing ac­cel­er­a­tors of dis­cov­ery. I could see this in Burn­ham’s face as he de­scribed the di­nosaur plumage un­earthed at Tanis – feath­ers made read­ily com­pre­hen­si­ble thanks to the dis­cov­ery in the 1990s of ex­quis­ite feath­ered fos­sils at Liaon­ing, China.

Within a short time, he said, scan­ning elec­tron mi­cro­scopes will ac­cess traces in the fos­sils that re­veal the pre­cise colours of those long-dead an­ces­tors of to­day’s birds.

Sci­en­tists will be un­pack­ing the trea­sures of Tanis for a half-cen­tury.


A tangled mass of fish from the de­posit in North Dakota’s Hell Creek for­ma­tion.

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