Paradoxides gracilis

Paradoxides is a genus of large to very large trilobite found throughout the world during the Middle Cambrian period. One record-breaking specimen of Paradoxides davidis, described by John William Salter in 1863, is 37 cm (15 in). The cephalon was semicircular with free cheeks ending in long, narrow, recurved spines. Eyes were crescent shaped providing an almost 360° view, but only in the horizontal plane. Its elongate thorax was composed of 19–21 segments and adorned with longish, recurved pleural spines. Its pygidium was comparatively small. Paradoxides is a characteristic Middle-Cambrian trilobite of the 'Atlantic' (Avalonian) fauna. Avalonian rocks were deposited near a small continent called Avalonia in the Paleozoic Iapetus Ocean. Avalonian beds are now in a narrow strip along the East Coast of North America, and in Europe.

Paradoxides gracilis

Ryan Schwark · CC0 · 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
ParadoxidesPBDB
Diet
carnivorePBDB, for Paradoxidoidea
Life habit
low-level epifaunalPBDB, for Redlichiida
Motility
fast-movingPBDB, for Redlichiida
Vision
well-developedPBDB, for Paradoxididae
Environment
marinePBDB, for Trilobita

Time the record covers

At most 12 million years on record.

Every occurrence read is dated to somewhere between 508.2 Mya and 497 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Cambrian — about 4 of 4 occurrencesCambrian508–508 Mya — about 0.0 occurrences508–507 Mya — about 0.0 occurrences507–507 Mya — about 0.0 occurrences507–507 Mya — about 0.0 occurrences507–506 Mya — about 0.1 occurrences506–506 Mya — about 0.2 occurrences506–505 Mya — about 0.2 occurrences505–505 Mya — about 0.2 occurrences505–505 Mya — about 0.2 occurrences505–504 Mya — about 0.2 occurrences504–504 Mya — about 0.2 occurrences504–503 Mya — about 0.2 occurrences503–503 Mya — about 0.2 occurrences503–503 Mya — about 0.2 occurrences503–502 Mya — about 0.2 occurrences502–502 Mya — about 0.2 occurrences502–501 Mya — about 0.2 occurrences501–501 Mya — about 0.2 occurrences501–501 Mya — about 0.2 occurrences501–500 Mya — about 0.2 occurrences500–500 Mya — about 0.2 occurrences500–499 Mya — about 0.2 occurrences499–499 Mya — about 0.1 occurrences499–499 Mya — about 0.1 occurrences499–498 Mya — about 0.1 occurrences498–498 Mya — about 0.1 occurrences498–497 Mya — about 0.1 occurrences497–497 Mya — about 0.1 occurrences508.7 Mya496.5 Mya

4 occurrences of Paradoxides gracilis 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

4 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

1 formation

  • Jince FormationVinice, Litavka, Středočeský kraj · CZ · 508.2–497 Mya4
Jince — 49.78°N, 13.98°EJince — 49.00°N, 14.00°E

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

Paradoxides gracilis and its relatives

Cambrian

Where Paradoxides gracilis and its relatives were recorded in the Cambrian.

Found in the same rock

24 taxa

The Paleobiology Database records 4 sites for Paradoxides gracilis, and this reads all of them. The number is how many of those sites it was catalogued from too.

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

4 references

Each of the 4 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. Each entry links to the Paleobiology Database's own record for the work.

Media and terms

Media content1

Picture of Paradoxides gracilis

Credit
Ryan Schwark
Licence
CC0
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 itParadoxides through timeFormations of the CambrianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Boeck 1827