Eodiscidae
Eodiscidae is a family of agnostid trilobites that lived during the final Lower Cambrian and the Middle Cambrian. They are small or very small, and have a thorax of two or three segments. Eodiscidae includes nine genera.

Dwergenpaartje · 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
- EodiscinaPBDB
- Diet
- detritivorePBDB, for Agnostida
- Life habit
- epifaunalPBDB, for Agnostida
- Motility
- slow-movingPBDB, for Agnostida
Time the record covers
At least 19 million years on record.
The record covers at least 516 Mya to 497 Mya. No occurrence read is dated outside 538.8 Mya to 486.85 Mya.
246 occurrences of Eodiscidae 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
246 occurrences- Cambrian100%
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
63 formations
- Kaili Formation45
- Shallow Bay Formation · Cow Head Group19
- Pioche Shale Formation17
- Sekwi Formation12
- Carrara Formation11
- Henson Gletscher Formation · Brønlund Fjord Group10
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The named rock units Eodiscidae has been recovered from, largest first. Drawn where the rock is now, not where it formed. 39 further formations hold fewer occurrences each and are not listed. 6 occurrences have no formation on record, which is common for older literature.
Eodiscidae and its relatives
CambrianWhere Eodiscidae and its relatives were recorded in the Cambrian.
Found in the same rock
899 taxa- Pagetia52 sites
- Kootenia30 sites
- Peronopsis29 sites
- Bathyuriscus14 sites
- Lingulella14 sites
- Pagetides14 sites
- Hyolithes13 sites
- Micromitra12 sites
- Olenoides12 sites
- Paterina12 sites
- Nisusia11 sites
- Zacanthoides gilberti11 sites
- Elrathina10 sites
- Zacanthoides10 sites
- Acrothyra9 sites
- Brachiopoda9 sites
- Chancia9 sites
- Elrathia9 sites
- Eoptychoparia9 sites
- Kootenia diutina9 sites
- Oryctocephalus9 sites
- Pagetides spinulus9 sites
- Trilobita9 sites
- Eodiscus punctatus8 sites
The Paleobiology Database records 159 sites for Eodiscidae, 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
83 references- Detailed trilobite biostratigraphy across the proposed GSSP for stage 5 ("Middle Cambrian" boundary) at the Wuliu-Zengjiayan section, Guizhou, China27
- Mid-Cambrian trilobites from the lowest part of the Cow Head Group, western Newfoundland19
- Lower and early Middle Cambrian trilobites from the Pioche Shale, East-Central Nevada, U.S.A.16
- Cambrian of the Hunan-Guizhou region, south China11
- Physical Stratigraphy and Trilobite Biostratigraphy of the Carrara Formation (Lower and Middle Cambrian) in the Southern Great Basin11
- Lower Cambrian trilobites from the Sekwi Formation type section, northwestern Canada10
- Middle Cambrian agnostoids and trilobites from the Lower Allochthon, Swedish Caledonides7
- Paleoecology of the Greater Phyllopod Bed community, Burgess Shale7
- A preliminary study on Lower-Middle Cambrian boundary and trilobite fauna at Balang, Taijiang, Guizhou, south China7
- Systematics and phylogenetics of polymeroid trilobites from the Henson Gletscher and Kap Stanton formations (Middle Cambrian), North Greenland7
- Trilobites and biostratigraphy of the Kuonamka Formation, northern Siberian Platform (Olenek River)5
- A new family of Cambrian rhynchonelliformean brachiopods (Order Naukatida) with an aberrant coral-like morphology5
Each of the 246 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. 71 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 Eodiscidae
- Source
- Wikipedia/Commons
- Credit
- Dwergenpaartje
- Licence
- CC BY-SA 3.0
- Commercial use
- the licence allows it
No 3D scan of Eodiscidae was found in Sketchfab.
Smithsonian Open Access and MorphoSource were not reached for this taxon, so this list is what the others held rather than everything there is.
The description on this site
- Source
- Wikipedia, “Eodiscidae”
- 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 itEodiscina through timeFormations of the CambrianThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Raymond 1913