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NEWS

December 2023 ESRFnews

ESRF featured in Netf lix

documentary

The ESRF has been featured in a new

Netflix documentary about the life and

work of the palaeoanthropologist and

long-term user Lee Berger.

“Unknown: Cave of Bones” follows

Berger’s journey from his discovery of

the world’s oldest non-human graveyard

in South Africa, to his quest to prove that

an ancient, ape-like creature practiced

complex burial rituals.

Currently “Explorer in Residence”

at the National Geographic Society in

the US, but still an honorary professor

at the University of the Witwatersrand

in South Africa, where he has spent

most of his academic career, Berger

is famous for having discovered two

new species of early human relatives,

Australopithecus sediba and Homo

naledi. He first brought the two-

million-year-old fossilised remains

of A. sediba to scan at the ESRF in

2010. The resulting data from that,

and subsequent scans, have been

used in a large number of scientific

and popular publications, and have

resulted in significant breakthroughs in

understanding the origins of humanity.

In February last year, Berger brought

A. sediba to the ESRF once again, this

time accompanied by the specimen of

a H. naledi child’s skeleton and other

objects potentially tools embedded

in a large block of rock The fossils

were scanned at the flagship EBS

beamline BM18 with the process and

extraordinary results featured in the

Netflix documentary

I came to this place this amazing

gigantic machine because its the only

machine on the planet that can take

this child in a plaster jacket and scan it

down to a millionth of a metre so we can

determine whether it is buried with a

tool Berger says in the film

E S R F/V U E D I C I K R A F T, P. E T A L./N A T U R E

ID19 scan of the

underside of the

trilobite, with its

exoskeleton

coloured in tan.

Contents of the

digestive tract are

separated and

colour-coded into

various fossil

groups.

“The ESRF played an absolutely

pivotal role in this study,” says Ahlberg.

“This scan was made at the old ID19

beamline before the EBS upgrade –

even better results are possible now.

Still, the resolution and scan quality it

provided were essential in identifying

the gut contents, piece by piece. A

conventional CT scan would have told

us that the trilobite had been eating;

only the ESRF could tell us what it had

been eating.”

The images showed that the

trilobite’s diet consisted of a range of

small “benthic” invertebrates that

live on the sea bed, including ostracods

(small crustaceans with paired shells),

echinoderms (animals related to

modern starfish and sea urchins)

and hyolithids (cone-shaped animals

with no living representatives). The

researchers believe that B. incola was

an opportunistic scavenger that fed

on dead or living animals – those that

disintegrated easily or were small

enough to be swallowed whole.

It is also likely that the scavenger was

itself scavenged. The images betrayed

the vertical tracks of other scavengers

that burrowed into the trilobite’s

carcass, where they targeted the soft

tissue. As they avoided the gut, the

researchers suppose that the trilobite’s

digestive system was noxious, and

possibly a site of ongoing enzymatic

activity (Nature DOI: 10.1038/

s41586-023-06567-7).

X-rays expose trilobite’s last

meal, 465 million years later

The gut contents of a 465-million-

year-old fossilised trilobite have been

imaged at the ESRF by synchrotron

microtomography. The results shed

light on one of the most common fossil

arthropods, in terms of its feeding

habits and its role in Palaeozoic

ecosystems.

Trilobites are among the most iconic

fossils, and formed a highly diverse,

abundant and important component

of marine ecosystems during most of

their 270-million-year-long history

from the early Cambrian to the end

of the Permian periods. But while

more than 20,000 species have been

studied, their feeding habits have had

to be inferred indirectly, due to the lack

of reported specimens with internal

gut contents. In a public Czech

collection, a specimen of one trilobite,

Bohemolichas incola, has had partly

visible gut contents, but until now

these have not been imaged for fears

of destroying it.

As synchrotron microtomography is

non-destructive, a team of researchers

led by Per Erik Ahlberg at Uppsala

University in Sweden and Valéria

Vaškaninová at Charles University

in the Czech Republic decided to

use the technique on the rare fossil

at the ESRF’s ID19 beamline.

Here, phase-contrast synchrotron

microtomography allowed the

researchers to map the contents of the

gut in 3D at high resolution.