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Mistaken Point's Fossils Lived Below the Sunlight

September 23, 2026 · Runtime 10:28 · Watch on YouTube

At Mistaken Point, Newfoundland, more than a hundred rock surfaces hold what the latest dating paper calls the oldest architecturally complex macrofossils, buried under thin layers of volcanic ash. The rock argues they lived on a deep slope, below storm waves and most likely below the light. The ash dates them to within six tenths of a million years. What they ate, and what they were, is still open.

Chapters

  1. 0:00 Turn off the sun
  2. 0:30 Mistaken Point, Newfoundland
  3. 0:52 A name that is a warning
  4. 1:24 Ash on a deep slope
  5. 1:48 The sun-fed reading
  6. 2:16 No waves in the rock
  7. 2:40 How deep? No number
  8. 3:15 Why the fronds survive
  9. 3:48 A current along the slope
  10. 4:19 Rangeomorphs dominate
  11. 4:49 What do you eat in the dark?
  12. 5:27 Were they animals?
  13. 6:03 Ash is the clock
  14. 6:33 574.17, 567.63, 565.00
  15. 7:16 Before and after the ice
  16. 7:56 The ash was a cycle
  17. 8:30 Two corrections
  18. 8:57 Measured, argued, open
  19. 9:27 The clock and the grave
  20. 9:57 Next: the Weng'an embryos

Transcript

Turn off the sun 0:00

Turn off the sun. Picture a sea floor where no wave ever reached and, most likely, no sunlight did either. Black water, soft mud, and every so often a slow fall of grey ash. On these rocks lie what the dating paper calls the oldest architecturally complex macrofossils, some of them nearly two metres long. The rock cannot tell us what they ate. But it can tell us exactly when the ash came down.

Mistaken Point, Newfoundland 0:30

This is Mistaken Point, on the southeastern tip of Newfoundland's Avalon Peninsula. More than a hundred bedding planes here carry the imprints of soft-bodied organisms, more than ten thousand impressions in all. By the end you will see what the rock pins down to within six tenths of a million years, what it only argues, and what it cannot say at all.

A name that is a warning 0:52

The name is a warning. Mistaken Point is named for the hazard it posed to ships on this foggy corner of the coast. This is Cape Race in eighteen sixty one, just along the same shore. The fossils went unnoticed until nineteen sixty seven, when a graduate student named Shiva Balak Misra and his field assistant Paul Thompson came across them while mapping the rocks. When one of the commonest of them was finally named, in two thousand and seven, it took his name: Fractofusus misrai.

Ash on a deep slope 1:24

Here is what the rock says happened, again and again. This was a deep slope on the edge of a volcanic arc. Fine ash fell out of the sky, settled through the water, and lay down as a thin layer on the mud. Each layer buried whatever was standing on the sea floor at that moment. Wood and colleagues counted the surfaces buried this way: more than a hundred.

The sun-fed reading 1:48

For a long time the tidy story was that these things lived on sunlight. In the nineteen eighties and nineties, geologists suggested the Ediacaran fossils were photosynthesisers, or in one case lichens. A garden that ran on light. That reading makes a prediction. Things that live on light live in shallow water, and shallow water leaves marks in rock: ripples, wave surfaces, shoals.

No waves in the rock 2:16

So what does the rock at Mistaken Point actually show? Thin beds of fine-grained sediment, laid down by turbidity currents that ran down a slope as muddy slurries. Debris flows. Slumped beds. And no wave-generated structures at all. The nearest ones sit more than a kilometre higher in the succession, in the Signal Hill Group.

How deep? No number 2:40

From that, Wood and colleagues argued for depth, in two thousand and three. Storm waves would have reached the sea floor if it lay above about fifty metres, so it lay below that. Much of the sediment is mud, and mud clouds water, so light was probably limited by turbidity. And the units lie a kilometre to a kilometre and a half below the first wave structures, which suggests the water may have been many hundreds of metres deep. Notice the verbs. The paper says the exact depth cannot be determined with precision.

Why the fronds survive 3:15

The same ash is why any of this survives. Nothing is uprooted and nothing is torn, so these organisms lived and died where they lie. Frond-shaped forms are found lying nearly flat, laid down by a current just before the ash arrived. Because they were already lying down, ash could not settle underneath them, and the blanket above cast a mould of their upper surface. On some surfaces only the holdfast discs remain, perhaps because the ash fell while the current was still and the fronds stood upright.

A current along the slope 3:48

That flat-lying is a compass. On most surfaces the fronds point across the ripples left by the downslope turbidity currents, which means a different current was running along the slope: a contour current. The authors suggested it was the delivery service. Oxygen and nutrients, carried past the sea floor by a steady bottom current, in a place that is otherwise short of both. And red mudstone in the same rocks is evidence that the bottom water carried oxygen.

Rangeomorphs dominate 4:19

Now look at who lived there. One group, the rangeomorphs, makes up upwards of seventy five percent of all the kinds of fossil at Mistaken Point. And on the two most famous surfaces, D and E, roughly ninety nine percent of the individual organisms. Rangeomorphs are branching forms, each branch made of smaller branches, self-similar over at least four scales in the best preserved fossils. There is no living animal built this way.

What do you eat in the dark? 4:49

So what do you eat in the dark? Nothing in these fossils has been read as a mouth or a gut. Two answers are on the table. One is osmotrophy: absorbing dissolved organic matter straight through the body surface. In two thousand and nine, Laflamme, Xiao and Kowalewski argued that the modular branches give the large surface area that this kind of feeding needs. The other is for one odd cone-shaped fossil, Thectardis, whose body plan looks like the water canals of a sponge. Both are hypotheses. Nobody has watched either happen.

Were they animals? 5:27

Were they animals at all? Others have proposed algae, fungi, lichens, even an extinct group of their own. The strongest answer so far came in twenty twenty one. Dunn and colleagues worked out how a Charnia grew, each new branch budding from an older one, and concluded it was a stem-group eumetazoan: an animal from a lineage with no living members. With no compelling case for muscles or a nervous system. The dating paper for Mistaken Point goes further and speaks of total-group animal body fossils, and even of locomotion.

Ash is the clock 6:03

Now the clock. You cannot date an imprint in mud. You can date a crystal. Zircon grains form in magma and lock uranium into their structure but almost no lead, so the lead that builds up afterwards is a timer. When the ash fell to this sea floor it brought those grains with it. Six ash beds, sampled by Matthews and colleagues, give six ages. Without the volcano, there would be no numbers.

574.17, 567.63, 565.00 6:33

Here they are. The oldest architecturally complex fossils, in the upper Drook Formation: five hundred and seventy four point one seven million years, give or take point six six. The exceptionally preserved Brasier surface: five hundred and sixty seven point six three. The famous E surface: five hundred and sixty five point zero zero. And the youngest rangeomorphs in the section, in the Fermeuse Formation, no older than five hundred and sixty four point one three. About fifteen hundred metres of rock and ten million years of sea floor. Forms with undisplayed branching come several million years before those with displayed branches.

Before and after the ice 7:16

And where does that sit against the ice? The Gaskiers glaciation of Newfoundland was over by five hundred and seventy nine point six million years ago, and lasted less than three hundred and forty thousand years. Brief, next to the snowball of episode three. The paper that dated it is called Dodging Snowballs. So the oldest complex fossils here come about five and a half million years after the ice. But older, simpler macrofossils, Palaeopascichnus, sit below the glacial rocks on the Bonavista Peninsula. Something macroscopic was already there before the ice.

The ash was a cycle 7:56

Then there is what happened between the ash falls. Each layer buried a community and, in effect, reset it. A twenty twenty six study of nineteen fossil communities from these rocks looked at what came back afterwards. Around fragments of Fractofusus lying on the buried floor, new Fractofusus were denser, which the authors read as fragments helping to restart the colony. That is a suggestion, not a proof. But it means the ash was not only an ending. It was a cycle.

Two corrections 8:30

Two corrections to last time. I said these were five hundred and sixty five million years old. That is the E surface. The oldest in this succession are about nine million years older. And I said the ash killed them. Whether every organism was dead before the ash arrived, the rock cannot say. What it records is burial: instant, and complete enough to cast a mould.

Measured, argued, open 8:57

So here is what Mistaken Point gives, sorted by how far you can trust it. The age is measured, to within about six tenths of a million years, from crystals in the ash. The setting is argued: below the storm waves, probably below the light, at a depth nobody has put a number on. And the biology is open. Probably animals, probably feeding without a mouth, in a body plan with no living relatives.

The clock and the grave 9:27

The picture most people carry is a garden: early animals grazing in warm, sunlit shallows. The rock argues that light away. What it gives instead is a date good to six tenths of a million years, written by a volcano, and a sea floor that fed its inhabitants on something other than sunshine. Ash dated them. Ash preserved them. And every layer of it was also a burial. The clock and the grave are the same bed of rock.

Next: the Weng'an embryos 9:57

Next time, we go older. Thirty million years older than Mistaken Point, or more, in phosphate rock from South China, there are tiny spheres that look like the first cell divisions of an embryo. For decades they were called the oldest animal embryos. Since then they have also been read as giant bacteria, and as single-celled organisms in resting cysts. The next episode is about the fossils that will not say what they are.

Description and sources

Wood et al. (2003): deep-marine turbidites at Mistaken Point, no wave structures (the nearest over 1 km higher), organisms most likely below the photic zone. No depth figure: storm wave base unlikely above about 50 m, and 1 to 1.5 km is rock thickness, not water depth. Ash cast moulds over fronds a current had laid flat. Matthews et al. (2021), U-Pb on zircon in six ash beds: upper Drook 574.17 ± 0.66 Ma, Brasier surface 567.63 ± 0.66, E surface 565.00 ± 0.64, youngest rangeomorphs 564.13 ± 0.65 at most, in about 1,500 m of strata. The Gaskiers glaciation was over by 579.63 Ma. No mouth or gut has been read in rangeomorphs; osmotrophy and sponge-like feeding are hypotheses. Dunn et al. (2021): Charnia is a stem-group eumetazoan. Corrects episode 11: 565.00 Ma is the E surface, the oldest is 574.17, and the rock records burial.

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.

  • djpmapleferryman — 2009-09-02 12:43:51 | Wikimedia Commons | CC BY 2.0
  • Illustrated London News — 1861-08-24 | Wikimedia Commons | Public domain
  • Kjoonlee — 2025-08-10 16:11:50 | Wikimedia Commons | CC BY 4.0
  • Zongjun Yin et al. — 2022 | Wikimedia Commons | CC BY 4.0

The 4 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. Four are archive images, credited on screen: a Fractofusus imprint in Ediacaran rock of Newfoundland (the file does not name the site), a replica of the Charnia masoni holotype from Charnwood Forest, an 1861 engraving of Cape Race, and an electron micrograph of an embryo-like fossil from the Weng'an Biota. The cover is a crop of the Charnia replica. None shows a Mistaken Point surface: photographs of the reserve carry a share-alike licence this channel does not use. The dark sea floor, volcanic island, mud slope and rippled surface are AI-generated reconstructions; no animal or fossil is generated. This video is labelled as containing altered or synthetic content. The diagrams are drawn in code from the published numbers.

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