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Cloudina's Holes: The Oldest Predator Nobody Has Found

October 30, 2026 · Runtime 8:47 · Watch on YouTube

Tubes a few millimetres wide, about 550 million years old, carry tiny bored holes read as the oldest evidence of predation. One count found 2.7% of more than 500 tubes bored; another found nearly one in five of about a hundred. What do the holes actually show?

Chapters

  1. 0:00 Holes, and no predator
  2. 0:15 Three questions
  3. 0:30 A correction: perforated, not round
  4. 0:53 A tube named for Preston Cloud
  5. 1:11 Funnels, not cones
  6. 1:32 On several continents
  7. 1:50 The Dengying Formation
  8. 2:14 1992: 2.7% of 500 tubes
  9. 2:33 If true, the oldest predation
  10. 2:51 Predator, or parasite?
  11. 3:09 2003: nearly one in five
  12. 3:29 Two counts, seven times apart
  13. 3:49 Two ranges of hole size
  14. 4:13 Where the holes sit
  15. 4:37 The tube with no holes
  16. 5:01 The driller nobody has found
  17. 5:26 Why one hole proves little
  18. 5:50 Three holes in Brazil
  19. 6:10 A correction: the Brazilian ash
  20. 6:33 Was the wall even mineral?
  21. 6:58 A gut, but not Cloudina's
  22. 7:20 The first reef, or rubble?
  23. 7:43 Measured, argued, open
  24. 8:04 Armour and the drill
  25. 8:23 Next: Namacalathus

Transcript

Holes, and no predator 0:00

The holes in Cloudina may be the oldest predator's work, and nobody has found the predator. Cloudina is a tube a few millimetres wide. We set the two founding counts of its holes side by side, and they do not agree.

Three questions 0:15

This is the end of the Ediacaran, about five hundred and fifty million years ago. By the end, you will know what the holes measure, what they are argued to mean, and what nobody can say yet: who made them, and even what the tube was made of.

A correction: perforated, not round 0:30

First, a correction to our last episode. We said the 2003 count found a neat, round boring through the wall. The summary of that paper says the shells are perforated, by borings fifteen to eighty-five micrometres wide. It does not say round. Rounded holes come from an earlier study, in 1992.

A tube named for Preston Cloud 0:53

Cloudina was described in 1972 from the Nama Group of Namibia, and named for the geologist Preston Cloud. It is a curved tube, from a fraction of a millimetre to eight millimetres across, and up to four centimetres long. Its wall is built of many thin layers.

Funnels, not cones 1:11

Look closely and the tube is a stack of funnels, each set inside the one before, often off centre. A 2005 study of new material from South China found no cross-walls, which ruled out the older picture of cones stacked like cups. Some tubes branch in two: a new funnel buds inside its parent.

On several continents 1:32

Cloudina turns up on several continents: in Namibia, where it was named, in South China, in Brazil, and tubes like it occur in rocks of the same age in Nevada. It is one of the markers geologists use to recognise the last few million years before the Cambrian.

The Dengying Formation 1:50

In South China it sits in the Dengying Formation. An ash at the base of the Dengying, in the Yangtze Gorges, is dated to five hundred and fifty-one million years. The formation runs up to the base of the Cambrian, about five hundred and thirty-nine million years ago. Cloudina appears in its middle part, the Gaojiashan Member, alongside another tube called Sinotubulites.

1992: 2.7% of 500 tubes 2:14

In 1992, Stefan Bengtson and Zhao Yue reported something on those tubes. Of more than five hundred from Shaanxi Province, two point seven percent had rounded holes, from forty to four hundred micrometres across. That is roughly fourteen tubes in every five hundred.

If true, the oldest predation 2:33

They saw a pattern. The size of the hole followed the width of the tube that was bored. That suggested an attacker choosing its prey for size, which is what a predator does. Their words were careful: if true, this would be the oldest case of predation in the fossil record.

Predator, or parasite? 2:51

The same year, the same group wrote that the tube may have protected the animal from predatorial and, or, parasitic attack. A parasite also bores. So from the very first report, the hole had two possible makers, and only one of them is a hunter.

2003: nearly one in five 3:09

Eleven years later, Hong Hua, Brian Pratt and a colleague counted again, in Cloudina from the uppermost Neoproterozoic of China. Nearly one fifth of almost one hundred tubes were perforated, by borings fifteen to eighty-five micrometres wide. They called them undoubted predatory borings.

Two counts, seven times apart 3:29

Put the two counts side by side. In 1992, two point seven percent of more than five hundred tubes. In 2003, nearly twenty percent of about a hundred. That is seven times the rate. Neither summary explains the difference, and we could not open either full paper.

Two ranges of hole size 3:49

The holes disagree as well. In 1992 they ran from forty to four hundred micrometres. In 2003, from fifteen to eighty-five. The two ranges share only the stretch between forty and eighty-five. Different beds, different places, or different rules for what counts as a hole: only the full papers could say.

Where the holes sit 4:13

What the 2003 study adds is a pattern. The holes sit at a fairly uniform distance from the opening of the tube. The authors offer two readings: the position of the sea floor, or, more likely in their view, a predator avoiding something protective near the opening. And because the holes vary in size, they suggest the driller kept hunting as it grew.

The tube with no holes 4:37

Then the contrast. Sinotubulites, a tube found with Cloudina, had no borings at all. The authors read that as selection: if the two lived the same way, Sinotubulites may have been guarded by organic material or by toxins. How many Sinotubulites were examined is not in the summary, and none out of many means more than none out of a few.

The driller nobody has found 5:01

And the driller itself? In the paper's words, the identity of the predator remains elusive. No body, no tooth, no drill has been found. For scale, a fossil moon snail hole measured in Korea averages four point two millimetres across, about fifty times the widest hole of 2003. Whatever bored Cloudina was very small.

Why one hole proves little 5:26

A round hole, on its own, is weak evidence. In tumbling experiments on modern shells, published in 2013, abrasion alone left holes that strongly resemble drilling. That study was not about Cloudina. But it is why the case rests on patterns: hole size tracking tube size, a preferred position, and one kind of tube left untouched.

Three holes in Brazil 5:50

In Brazil, near Corumba, a 2017 study found three Cloudina with circular to oval holes, from one hundred and eighty-seven to two hundred and thirty-seven micrometres. Micro tomography showed the hole continuing into the tube. The authors labelled them possible predatory holes.

A correction: the Brazilian ash 6:10

And a second correction to our last episode. We said small traces there lie above a five hundred and fifty-five million year old ash, together with Cloudina. In the dating study, that ash sits below the formation and gives only its maximum age. The traces are thirty to forty metres above its base, and Cloudina appears in its upper part.

Was the wall even mineral? 6:33

Cloudina is often called one of the first animals to build a mineral skeleton. That, too, is argued. A 2020 study of cloudinid tubes from China read their walls as originally organic, turned to calcite or aragonite only after death. A 2026 study argues the same for two tube fossils, and places the first unequivocal mineral skeletons in the Cambrian.

A gut, but not Cloudina's 6:58

Even the animal inside is mostly inferred. In 2020, scans of tubes related to Cloudina, from Nevada, showed a cylinder inside the tube that may be a gut. Those tubes could not be assigned to a genus, and the authors write that alternative interpretations are plausible. It is not Cloudina's gut.

The first reef, or rubble? 7:20

Cloudina is also said to have built the first animal reefs. A 2014 study in Namibia described tubes attached and cemented to each other. A 2018 study rebuilt Cloudina clusters in three dimensions, slice by slice, and found transported remains, piled up after death. The reef, too, is an argument.

Measured, argued, open 7:43

So here is what the rock allows. Measured: holes in Cloudina, in two counts that do not agree, and three more in Brazil. Argued: that a predator made them, choosing its prey. Open: who drilled, whether it was a hunter or a parasite, and whether the wall it went through was mineral at all.

Armour and the drill 8:04

Both founding papers make the same larger claim: that predation helped drive animals to build skeletons, around the start of the Cambrian. If the holes are what they seem, armour and the drill arrived together. The evidence is a hole a fraction of a millimetre wide, and a predator that has never been seen.

Next: Namacalathus 8:23

Next time, a goblet on a stalk, from the same Namibian limestones as Cloudina. It is called Namacalathus. In 2015, researchers read the fine grain of its wall and placed it near brachiopods and bryozoans, animals with a crown of tentacles. The question is how much a wall can say about the animal that built it.

Description and sources

Cloudina, a curved tube of nested funnels from the end of the Ediacaran (about 550–539 Ma), found in Namibia, South China and Brazil. Bengtson & Zhao (Science, 1992) found rounded holes 40–400 µm across in 2.7% of more than 500 tubes from Shaanxi, with hole size following tube width, and wrote that, if true, this would be the oldest case of predation. Hua, Pratt & Zhang (Palaios, 2003) found nearly one fifth of almost one hundred tubes perforated by borings 15–85 µm wide, at a fairly uniform distance from the opening, and none in the co-occurring Sinotubulites; the predator's identity, they write, remains elusive. Three more bored tubes come from Corumbá, Brazil (187–237 µm, 2017). Neither founding summary explains why the counts differ. Whether the borer was a predator or a parasite, and whether the tube wall was even mineral, are still argued.

PRINT-READY, FROM THIS CHANNEL

The Deep Time Record, Vol. 01 — the cores, the curves and the clocks

https://therepository.gumroad.com/l/deep-time-record

PRIMARY SOURCES

ARCHIVE IMAGES — author, date, archive and licence.

  • James St. John — 2018-12-02 15:16 | Wikimedia Commons | CC BY 2.0
  • R.R. Adôrno et al. — 2019-11-12 | Wikimedia Commons | CC BY 4.0

... and 3 more, each credited on screen in the video and listed in this project's manifest.

The 2 generated plates were made for this channel with FLUX.1-schnell. No person is depicted in any of them.

Deep Time Archives rebuilds the pre-human Earth from the physical record — outcrops, drill cores, golden spikes, catalogued specimens. Every episode starts from an object you can go and check, and the sources are listed above.

About the images. No bored tube is shown in a photograph: the figures of the bored specimens are not openly licensed, so the holes are drawn in code from the published numbers. The fossils shown are real: Cloudina from Corumbá, Brazil (James St. John, CC BY 2.0), Cloudina carinata from the Tamengo Formation (Adôrno et al., CC BY 4.0), Namacalathus and Cloudina at the Redpath Museum (Daderot, CC0) and Corumbella (Detlef Walde, CC0). The Yangtze Gorges are seen from orbit (NASA Earth Observatory, public domain). The shallow-sea scenes are AI-generated reconstructions of places; no organism, tube or hole is generated. This video is labelled as containing altered or synthetic content.

#DeepTime #EarthHistory #Ediacaran #Paleontology #Evolution