Tricrepicephalus

Tricrepicephalus is an extinct genus of ptychopariid trilobites of the family Tricrepicephalidae with species of average size. Its species lived from 501 to 497 million years ago during the Dresbachian faunal stage of the late Cambrian Period. Fossils of Tricrepicephalus are widespread in Late Cambrian deposits in North America, but is also known from one location in South America. Tricrepicephalus has an inverted egg-shaped exoskeleton, with three characteristic pits in the fold that parallels the margin of the headshield just in front of the central raised area. The articulating middle part of the body has 12 segments and the tailshield carries two long, tubular, curved pygidial spines that are reminiscent of earwig's pincers that rise backwards from the plain of the body at approximately 30°.

Tricrepicephalus

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
TricrepicephalidaePBDB
Diet
carnivorePBDB, for Trilobita
Life habit
low-level epifaunalPBDB, for Trilobita
Motility
fast-movingPBDB, for Trilobita
Vision
well-developedPBDB, for Tricrepicephalidae
Environment
marinePBDB, for Trilobita

Time the record covers

At least 2.5 million years on record.

The record covers at least 499.5 Mya to 497 Mya. No occurrence read is dated outside 506.5 Mya to 486.85 Mya.

Cambrian — about 116 of 116 occurrencesCambrianOrdovician — about 0 of 116 occurrences507–506 Mya — about 0.0 occurrences506–506 Mya — about 0.0 occurrences506–505 Mya — about 0.0 occurrences505–504 Mya — about 0.8 occurrences504–504 Mya — about 2 occurrences504–503 Mya — about 2 occurrences503–502 Mya — about 2 occurrences502–501 Mya — about 2 occurrences501–501 Mya — about 2 occurrences501–500 Mya — about 6 occurrences500–499 Mya — about 8 occurrences499–499 Mya — about 8 occurrences499–498 Mya — about 8 occurrences498–497 Mya — about 8 occurrences497–497 Mya — about 7 occurrences497–496 Mya — about 5 occurrences496–495 Mya — about 5 occurrences495–495 Mya — about 5 occurrences495–494 Mya — about 5 occurrences494–493 Mya — about 4 occurrences493–493 Mya — about 4 occurrences493–492 Mya — about 4 occurrences492–491 Mya — about 4 occurrences491–490 Mya — about 4 occurrences490–490 Mya — about 4 occurrences490–489 Mya — about 4 occurrences489–488 Mya — about 4 occurrences488–488 Mya — about 4 occurrences488–487 Mya — about 4 occurrences487–486 Mya — about 1 occurrence499.5 Mya – 497 Mya507 Mya486.4 Mya

116 occurrences of Tricrepicephalus 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

116 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

Riley — 30.64°N, 99.26°WRiley — 30.92°N, 98.61°WRiley — 30.81°N, 98.28°WRiley — 30.91°N, 99.00°WRiley — 30.76°N, 99.41°WRiley — 30.54°N, 99.09°WRiley — 30.49°N, 98.52°WRiley — 30.81°N, 98.37°WDeadwood — 43.85°N, 103.36°WDeadwood — 44.42°N, 103.71°WDeadwood — 44.25°N, 103.78°WDeadwood — 44.28°N, 103.73°WDeadwood — 44.25°N, 103.57°WDeadwood — 44.07°N, 103.22°WDeadwood — 44.00°N, 103.00°WDeadwood — 44.45°N, 104.42°WDeadwood — 43.72°N, 103.67°WNolichucky — 36.75°N, 82.25°WNolichucky — 36.21°N, 83.28°WNolichucky — 39.57°N, 106.47°WNolichucky — 36.03°N, 84.08°WRabbitkettle — 64.67°N, 132.00°WRabbitkettle — 62.70°N, 128.38°WOrr — 38.80°N, 113.35°WOrr — 39.21°N, 113.32°WOrr — 38.54°N, 113.54°WWeeks — 39.22°N, 113.34°WWeeks — 39.22°N, 113.40°WWeeks — 39.45°N, 113.80°WPilgrim — 44.66°N, 111.10°WDuNoir Limestone — 43.29°N, 109.83°WBonneterre — 37.82°N, 90.68°WRoad River — 66.42°N, 135.53°WEau Claire — 39.64°N, 86.86°WWarrior — 40.82°N, 77.93°WChefu — 27.48°N, 109.20°EEmigrant — 37.79°N, 117.44°WGrosses-Roches — 48.93°N, 67.17°WLa Cruz Limestone — 32.87°S, 69.69°W

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The named rock units Tricrepicephalus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 1 occurrence has no formation on record, which is common for older literature.

Tricrepicephalus and its relatives

Cambrian

Where Tricrepicephalus and its relatives were recorded in the Cambrian.

Found in the same rock

209 taxa

The Paleobiology Database records 98 sites for Tricrepicephalus, 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

27 references

Each of the 116 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. 15 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 Tricrepicephalus

Credit
Dwergenpaartje
Licence
CC BY-SA 3.0
Commercial use
the licence allows it

No 3D scan of Tricrepicephalus 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 itTricrepicephalidae through timeFormations of the CambrianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Kobayashi 1935