Ctenocystoidea

Ctenocystoidea is an extinct clade of echinoderms, which lived during the Cambrian and Ordovician periods. Unlike other echinoderms, ctenocystoids had bilateral symmetry, or were only very slightly asymmetrical. They are believed to be one of the earliest-diverging branches of echinoderms, with their bilateral symmetry a trait shared with other deuterostomes. Ctenocystoids were once classified in the taxon Homalozoa, also known as Carpoidea, alongside cinctans, solutes, and stylophorans. Homalozoa is now recognized as a polyphyletic group of echinoderms without radial symmetry. Ctenocystoids were geographically widespread during the Middle Cambrian, with one species surviving into the Late Ordovician.

Ctenocystoidea

Samuel Zamora, Imran A. Rahman, Andrew B. Smith · 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
EchinodermataPBDB
Life habit
epifaunalPBDB
Environment
marinePBDB

Time the record covers

At least 47 million years on record.

The record covers at least 505.3 Mya to 458.2 Mya. No occurrence read is dated outside 514.5 Mya to 452.8 Mya.

Cambrian — about 33 of 34 occurrencesCambrianOrdovician — about 1 of 34 occurrencesOrdovician516–514 Mya — about 0.2 occurrences514–511 Mya — about 0.4 occurrences511–509 Mya — about 0.9 occurrences509–507 Mya — about 4 occurrences507–505 Mya — about 7 occurrences505–503 Mya — about 6 occurrences503–501 Mya — about 6 occurrences501–499 Mya — about 5 occurrences499–496 Mya — about 3 occurrences496–494 Mya — about 0.8 occurrences494–492 Mya — about 0.1 occurrences460–458 Mya — about 0.0 occurrences458–456 Mya — about 0.4 occurrences456–454 Mya — about 0.4 occurrences454–452 Mya — about 0.2 occurrences505.3 Mya458.2 Mya516 Mya452 Mya

34 occurrences of Ctenocystoidea on record, most of them in the Cambrian. 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

34 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

12 formations

Jince — 49.78°N, 13.97°EJince — 49.00°N, 14.00°ELead Bell Shale — 42.00°N, 112.00°WLangston — 41.60°N, 112.04°WLangston — 42.37°N, 111.51°WLangston — 41.97°N, 111.70°WUsarzow Sandstone — 50.70°N, 21.38°EUsarzow Sandstone — 50.68°N, 21.55°EFerrals — 43.40°N, 2.63°EJbel Wawrmast — 31.29°N, 5.50°WBalclatchie — 55.21°N, 4.82°WNivel E — 43.40°N, 2.63°EIsandula Road — 41.23°S, 146.13°EMurero — 41.67°N, 1.77°WWheeler Shale — 39.40°N, 113.28°WMaentwrog — 52.93°N, 3.94°W

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

Ctenocystoidea and its relatives

Cambrian

Where Ctenocystoidea and its relatives were recorded in the Cambrian.

Found in the same rock

165 taxa

The Paleobiology Database records 29 sites for Ctenocystoidea, 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

20 references

Each of the 34 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. 8 further references are 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 Ctenocystoidea

Credit
Samuel Zamora, Imran A. Rahman, Andrew B. Smith
Licence
CC BY 4.0
Commercial use
the licence allows it

No 3D scan of Ctenocystoidea 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 itEchinodermata through timeFormations of the CambrianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Robison and Sprinkle 1969