Uncus

Uncus dzaugisi was an organism which lived approximately 560 to 550 million years ago during the late Ediacaran in what is now Southern Australia and Newfoundland and Labrador. Its smooth cylindrical shape, with one end being wider than the other, suggests that it was a member of the clade Ecdysozoa. If true, this makes it the oldest ecdysozoan known so far, as well as one of the oldest known bilaterians. It is currently the only member of the genus Uncus.

A picture published with the record for Uncus. What it shows has not been checked.

Domenic Pennetta · CC BY 4.0 · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.

On record

Recorded, not inferred
Sits inside
EcdysozoaPBDB

Time the record covers

At most 97 million years on record.

Every occurrence read is dated to somewhere between 635 Mya and 538.8 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Cambrian — about 0 of 2 occurrences637–634 Mya — about 0.0 occurrences634–630 Mya — about 0.1 occurrences630–627 Mya — about 0.1 occurrences627–624 Mya — about 0.1 occurrences624–620 Mya — about 0.1 occurrences620–617 Mya — about 0.1 occurrences617–614 Mya — about 0.1 occurrences614–610 Mya — about 0.1 occurrences610–607 Mya — about 0.1 occurrences607–604 Mya — about 0.1 occurrences604–600 Mya — about 0.1 occurrences600–597 Mya — about 0.1 occurrences597–594 Mya — about 0.1 occurrences594–590 Mya — about 0.1 occurrences590–587 Mya — about 0.1 occurrences587–584 Mya — about 0.1 occurrences584–580 Mya — about 0.1 occurrences580–577 Mya — about 0.1 occurrences577–574 Mya — about 0.1 occurrences574–570 Mya — about 0.1 occurrences570–567 Mya — about 0.1 occurrences567–564 Mya — about 0.1 occurrences564–560 Mya — about 0.1 occurrences560–557 Mya — about 0.1 occurrences557–554 Mya — about 0.1 occurrences554–550 Mya — about 0.1 occurrences550–547 Mya — about 0.1 occurrences547–544 Mya — about 0.1 occurrences544–540 Mya — about 0.1 occurrences540–537 Mya — about 0.0 occurrences637 Mya537 Mya

2 occurrences of Uncus on record. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.

When

2 occurrences

These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.

Found in

2 formations

Rawnsley Quartzite — 30.97°S, 138.18°EFermeuse — 47.65°N, 53.22°W

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The named rock units Uncus has been recovered from, largest first. Drawn where the rock is now, not where it formed.

Found in the same rock

33 taxa

The Paleobiology Database records 2 sites for Uncus, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.

This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.

Entered from

2 references

Each of the 2 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.

Media and terms

Media content1

Picture of Uncus

Credit
Domenic Pennetta
Licence
CC BY 4.0
Commercial use
the licence allows it

No 3D scan of Uncus was found in MorphoSource and Sketchfab.

Smithsonian Open Access was not reached for this taxon, so this list is what the others held rather than everything there is.

The description on this site

Licence
CC BY-SA 4.0

This is what the site found, which is not the same as what exists.

Keep going

What may have been alongside itEcdysozoa through time

Occurrence data from the Paleobiology Database, CC BY 4.0. Hughes et al. 2024