Cyclopygidae
Cyclopygidae is a family of asaphid trilobites from the Ordovician. Cyclopygids had an extratropical distribution, and there is evidence that they lived in darker parts of the water column. Cyclopygids are characterized by enlarged eyes, with a wide angle of view, both horizontal and vertical, reminiscent of the eyes of dragonflies. These typically touch the glabella directly on the side. Cyclopygids all lack genal spines, but Symphysops carries a forward directed frontal spine on the glabella. It is presumed that at least the members of the genus Pricyclopyge swam upside down and had bioluminescent organs on the third thorax segment. Cyclopygids had between 7 and 5 thorax segments, a wide and stout axis, and short side lobes.

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
- CyclopygoideaPBDB
- Diet
- microcarnivorePBDB
- Life habit
- nektonicPBDB
- Motility
- actively mobilePBDB
- Vision
- well-developedPBDB
- Environment
- marinePBDB, for Trilobita
Time the record covers
At least 28 million years on record.
The record covers at least 477.1 Mya to 448.8 Mya. No occurrence read is dated outside 486.85 Mya to 443.1 Mya.
314 occurrences of Cyclopygidae on record, most of them in the Ordovician. 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
314 occurrences- Ordovician100%
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
74 formations
- Llanfallteg Formation29
- Grande Coupe Formation15
- Domusnovas Formation15
- Tangtou Formation14
- Sarka Formation13
- Pontyfenni Formation12
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The named rock units Cyclopygidae has been recovered from, largest first. Drawn where the rock is now, not where it formed. 50 further formations hold fewer occurrences each and are not listed. 32 occurrences have no formation on record, which is common for older literature.
Cyclopygidae and its relatives
OrdovicianWhere Cyclopygidae and its relatives were recorded in the Ordovician.
Found in the same rock
1,415 taxa- Cyclopyge103 sites
- Dionide36 sites
- Geragnostus33 sites
- Lonchodomas30 sites
- Ovalocephalus30 sites
- Nileus29 sites
- Nankinolithus28 sites
- Illaenus24 sites
- Ampyx23 sites
- Corrugatagnostus23 sites
- Microparia22 sites
- Remopleurides22 sites
- Birmanites21 sites
- Pricyclopyge21 sites
- Ectillaenus18 sites
- Paraphillipsinella18 sites
- Telephina17 sites
- Amphitryon16 sites
- Symphysops15 sites
- Symphysurus15 sites
- Trinodus15 sites
- Michelinoceras14 sites
- Ormathops13 sites
- Shumardia13 sites
The Paleobiology Database records 196 sites for Cyclopygidae, 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
70 references- Ordovician (Darriwilian-early Katian) trilobite faunas of northwestern Tarim, Xinjiang, China27
- Ordovician (Llanvirn) Trilobites from SW Wales26
- Early Ordovician (Arenig) stratigraphy and faunas of the Carmarthen District, southwest Wales25
- The biostratigraphy of the Ordovician of Bohemia19
- Regional stratigraphic table of Eastern China, Zhejiang Province14
- New brachiopods and trilobites from the Ordovician of Perce, Quebec14
- New deeper - water trilobites in the Ordovician of the Prague Basin (Czech Republic)12
- Chlupáč et al., 199810
- Trilobites of the post-Sardic (Upper Ordovician) sequence of southern Sardinia. Part I9
- Ordovician and Silurian trilobite faunas of the White Head Formation, Percé Region, Québec9
- Summary of regional geology of Hu''nan Province, China8
- The ecological significance of variation in the genesis composition of Rawtheyan (Late Ordovician) trilobite faunas from North Wales, U.K8
Each of the 314 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. 58 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 Cyclopygidae
- Source
- Wikipedia/Commons
- Credit
- Dwergenpaartje
- Licence
- CC BY-SA 3.0
- Commercial use
- the licence allows it
No 3D scan of Cyclopygidae 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
- 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 itCyclopygoidea through timeFormations of the OrdovicianThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Raymond 1925