Spy, near the Orneau, Belgium
Spy Cave
About 44,200 to 40,600 years ago, in the later dating (older collagen dates were younger by up to 10,000 years)
Neanderthal bones from Spy were once dated as young as about 23,880 radiocarbon years, and a vertebra at 36,250 plus or minus 500. A method that isolates one amino acid makes the same bones older by as much as about 10,000 years.
Why this is extraordinary
In 1886, diggers in a small cave at Spy, on the Orneau in Namur, found Neanderthal skeletons. For a long time the bones sat near the end of the Neanderthal story in northwest Europe. Direct radiocarbon on bulk collagen, the protein in the bone, produced ages as young as 23,880 plus or minus 240 radiocarbon years (OxA-8912). A vertebra, Spy 737a, measured 36,250 plus or minus 500 (OxA-10560). Other pieces fell in the low and middle thirties of thousands of radiocarbon years. If those numbers were the death of the people, Neanderthals were still at Spy when later humans were already in the region.
A 2021 redating used a single amino acid from the collagen, hydroxyproline, which is harder for stray carbon to imitate. Soil and conservation products had been making the bulk dates too young. On the same vertebra the new age is 41,600 plus or minus 2,400 radiocarbon years (OxA-X-2762-6). A piece first dated 33,950 plus or minus 550 and 33,450 plus or minus 600 came out at 41,700 plus or minus 2,300. A tooth first dated 34,650 plus or minus 600 came out at 41,500 plus or minus 1,800. The errors are wider. The direction is the same: older, by as much as about 10,000 years. Put with other Belgian specimens, the study’s model places the disappearance of this population at 44,200 to 40,600 calibrated years before present, at 95.4 percent.
One bone will not join that model. The scapula Spy 572a had given very young dates, around the twenty-thousands. Genomic work found modern cattle DNA in it. A glue made from cattle bone had been put on the fossil. Every radiocarbon age of that scapula, including one on hydroxyproline, is set aside, because the glue and the bone cannot be separated cleanly. A young date that is glue is not a late Neanderthal.
A published reply takes the new window as premature for a different reason. Except for that scapula, the redated pieces were found on the slope in front of the cave, long after 1886, most probably in the waste of the old dig. Some of them refit the 1886 skeletons, including a maxilla and a molar that fit the original jaw. Others are only Neanderthal bone from the slope. The reply says the little stratigraphy that was written down in 1886 still has to be in the argument, and that so far the new protocol has a firm result on one of the two original skeletons. The chemistry and the spoil heap are both real. No alignment of the cave mouth is published in these papers. The opening in the photograph faces the bushes. It is not a measured sunrise.
Why it matters
If the older ages hold, northwest Europe’s Neanderthals were gone by about 44,200 to 40,600 calibrated years before present. If the slope finds are not the 1886 skeletons, that window is a date on loose bone, and the people in the cave are still waiting for the same chemistry.
The photograph is the cave mouth from inside. The bones, the glue, and the two clocks are the argument.
Photo tour
1 photograph, unedited. On a phone, swipe the row. Choose one to look closely.
- The photograph is the cave. The bones and the glued scapula are not in it.
What is still unexplained
These sit beside the consensus account, with the same visual weight. None of them is marked solved.
Location and dating
- Location
- Spy Cave, at Spy in the province of Namur, beside the Orneau. The pin is the cave. The bones are in collections, not in the photograph.
- Period label
- Current consensus — open to revision Late Neanderthals. Bulk collagen had placed some of them among the last in northwest Europe. The hydroxyproline model places the disappearance at 44,200 to 40,600 calibrated years before present.
- How this dating was done
- Radiocarbon on bone collagen, first on the bulk protein and then on the single amino acid hydroxyproline. A genomic check found cattle DNA in the glued scapula.
- What could change it
- The same amino-acid date on the 1886 skeletons that still lack one, with a record of which layer they came from, would decide whether the slope and the cave are one event.
What is actually there
- A bulk date on one Spy specimen was 23,880 plus or minus 240 radiocarbon years.
- The vertebra moved from 36,250 plus or minus 500 to 41,600 plus or minus 2,400.
- The scapula Spy 572a carries modern cattle DNA from a bone glue.
- The disappearance model is 44,200 to 40,600 calibrated years before present, at 95.4 percent.
- No sunrise or star is published for the cave mouth.
Open questions
| Question | Status |
|---|---|
| Were the youngest bulk dates the people, or the contamination? | The hydroxyproline ages are older. The glued scapula is contamination. The other young bulk dates are the ones the new method was built to replace. |
| Do the slope bones belong to the 1886 skeletons? | Open. One jaw refits. The spoil heap is still the context of several of the new dates. |
The current narrative
Where publication stands today. It is the best-supported reading, and it is open to revision. It is not a verdict.
The current narrative — open to revision
Gone by about 44,200 to 40,600 years ago
Once glue and soil carbon are kept out of the measurement, the Spy Neanderthals are not among the last in northwest Europe. This population disappears in a window of 44,200 to 40,600 calibrated years before present.
What supports this
- The same bones come out older when only hydroxyproline is dated, by as much as about 10,000 years.
- The scapula that stayed young is contaminated with modern cattle collagen.
- The model uses more than one Belgian site, not a single laboratory number.
What pushes back
- Several dated pieces were found on the slope, probably in old spoil, not in a layer notebook from 1886.
- The new errors are thousands of years wide.
- The reply says the new protocol is firm so far on one of the two original skeletons.
What would settle it
It is the centre for the chemistry. A date that was glue is not a late survival. Whether every older number is one of the 1886 bodies is the part the slope still holds open.
Emerging narratives
Other published readings. Each may be right. None is adopted here unless the evidence carries it.
An emerging narrative
Still late, if the cave and the slope are different
The 1886 skeletons may be younger than the slope fragments, and the disappearance window mixes bones that were not found together.
What supports this
- The reply ties most of the new dates to spoil on the slope, collected long after the original dig.
- A written stratigraphy, however thin, exists for the 1886 finds and is not the same thing as a bag from the talus.
- Only some pieces refit the original skeletons.
What pushes back
- The maxilla and molar from the slope refit the 1886 jaw, and they are among the older results.
- The very young scapula is explained by cattle glue, not by a late death.
- Bulk collagen is the method the contamination study was designed to replace.
What would settle it
The slope is a real caution. It does not put the glue date back into the story. A late Spy Neanderthal now needs a clean amino-acid age on a bone whose 1886 context is written down.
Should the current view be reevaluated?
Open to revision
The young bulk ages do not survive the amino-acid method, and the glued scapula is not a person of that date. The 44,200 to 40,600 window is the published model. Which of those older bones are the skeletons of 1886 is still argued. No sky reading is published for the cave.
What drives this
- A bulk age as young as 23,880 plus or minus 240 radiocarbon years.
- Hydroxyproline ages older by as much as about 10,000 years.
- Cattle glue on Spy 572a, and slope finds that only partly refit the 1886 skeletons.
This is the museum’s own weighing of the evidence. It is not a visitor vote, and it is separate from the slider.
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If the contested reading is right
What would follow if a reading that is not the consensus turned out to be true, and what could settle it. This explains the stakes. It does not adopt the reading.
The whole group is inside the older window
Northwest Europe would have lost its Neanderthals earlier than the bulk-collagen story allowed, and Spy would not be a last refuge.
Why it is still worth a test
Amino-acid dates on the remaining 1886 bones, each tied to the notes from the cave rather than to the slope.
The 1886 skeletons are a later death than the slope
Two times would be hiding in one cave’s collection, and the disappearance model would be dating the spoil.
Why it is still worth a test
A refit or a recorded layer that puts an 1886 bone in the young range after the glue is gone.
Sources
- Reevaluating the timing of Neanderthal disappearance in Northwest Europe Proceedings of the National Academy of Sciences
- The stratigraphic context of Spy Cave and the timing of Neanderthal disappearance Proceedings of the National Academy of Sciences
- New data on the late Neandertals, direct dating of the Belgian Spy fossils American Journal of Physical Anthropology
Image credits
- Spy Cave, looking out. The arch is rough limestone. The floor inside is gravel. The bones are not in the frame. The file identifies this as the cave where remains were found in 1886. . Bel Adone, Public domain. Shown unedited.