Holonema

Holonema is an extinct genus of relatively large, barrel-shaped arthrodire placoderms that were found in oceans throughout the world from the Mid to Late Devonian, when the last species perished in the Frasnian-Fammian extinction event. Most species of the genus are known from fragments of their armor, but the Gogo Reef species, H. westolli, is known from whole, articulated specimens.

Holonema

Mr Fink ( talk ) · CC BY-SA 3.0 · 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
HolonematidaePBDB
Diet
carnivorePBDB, for Arthrodira
Life habit
nektonicPBDB, for Arthrodira
Motility
actively mobilePBDB, for Arthrodira

Time the record covers

At least 21 million years on record.

The record covers at least 393.47 Mya to 372.15 Mya. No occurrence read is dated outside 399.5 Mya to 358.86 Mya.

Devonian — about 24 of 24 occurrencesDevonianCarboniferous — about 0 of 24 occurrences400–399 Mya — about 0.1 occurrences399–397 Mya — about 0.2 occurrences397–396 Mya — about 0.2 occurrences396–395 Mya — about 0.2 occurrences395–393 Mya — about 0.3 occurrences393–392 Mya — about 0.8 occurrences392–390 Mya — about 0.8 occurrences390–389 Mya — about 0.8 occurrences389–388 Mya — about 1 occurrence388–386 Mya — about 4 occurrences386–385 Mya — about 2 occurrences385–383 Mya — about 1 occurrence383–382 Mya — about 1 occurrence382–381 Mya — about 2 occurrences381–379 Mya — about 2 occurrences379–378 Mya — about 1 occurrence378–376 Mya — about 1 occurrence376–375 Mya — about 1 occurrence375–374 Mya — about 0.6 occurrences374–372 Mya — about 0.6 occurrences372–371 Mya — about 0.2 occurrences371–369 Mya — about 0.2 occurrences369–368 Mya — about 0.2 occurrences368–367 Mya — about 0.2 occurrences367–365 Mya — about 0.2 occurrences365–364 Mya — about 0.2 occurrences364–362 Mya — about 0.2 occurrences362–361 Mya — about 0.2 occurrences361–359 Mya — about 0.2 occurrences359–358 Mya — about 0.1 occurrences393.47 Mya372.15 Mya400.3 Mya358 Mya

24 occurrences of Holonema on record, most of them in the Devonian. 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

24 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

16 formations

Chemung — 41.68°N, 76.71°WNarva — 59.38°N, 28.19°EAruküla — 57.55°N, 25.28°ERockport Quarry Limestone — 45.20°N, 83.39°WCatskill — 41.81°N, 77.78°WAruküla — 59.37°N, 25.08°EBurtnieki — 58.10°N, 25.55°EBahram — 30.76°N, 57.03°EGneudna — 24.06°S, 115.21°EMartin — 35.25°N, 111.61°WGenshaw — 45.19°N, 83.48°WNewton Creek Limestone — 45.37°N, 84.22°WPickwell Down Sandstone — 51.17°N, 4.21°WJiucheng — 25.54°N, 102.43°EKush Yeilagh — 36.85°N, 55.35°EGogo — 18.16°S, 124.30°E

Loading coastlines…

The named rock units Holonema has been recovered from, largest first. Drawn where the rock is now, not where it formed. 4 occurrences have no formation on record, which is common for older literature.

Holonema and its relatives

Devonian

Where Holonema and its relatives were recorded in the Devonian.

Found in the same rock

182 taxa

The Paleobiology Database records 21 sites for Holonema, 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

13 references

Each of the 24 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. 1 further reference is not listed. 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 Holonema

Credit
Mr Fink ( talk )
Licence
CC BY-SA 3.0
Commercial use
the licence allows it

No 3D scan was found. Smithsonian Open Access, MorphoSource and Sketchfab were all searched.

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 itHolonematidae through timeFormations of the DevonianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Newberry 1890