Pachycephalosaurus

Pachycephalosaurus is a genus of pachycephalosaurid ornithischian dinosaur. The type species, P. wyomingensis, is the only known definitive species. It was among the last species of non-avian dinosaurs on Earth before the Cretaceous–Paleogene extinction event, which lived during the Maastrichtian age of the Late Cretaceous period in what is now western North America. Remains have been excavated in Montana, South Dakota, Wyoming, and Alberta. Mainly known from a single skull and a few extremely thick skull roofs, Pachycephalosaurus is estimated to have reached 4.5 m (15 ft) long and weighed 370–450 kg (820–990 lb). More complete fossils would come to be found in the following years.

A picture published with the record for Pachycephalosaurus.

IJReid · 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
EupachycephalosauriaPBDB
Diet
herbivorePBDB, for Ornithischia
Life habit
ground dwelling, gregariousPBDB, for Ornithischia
Motility
actively mobilePBDB, for Ornithischia
Environment
terrestrialPBDB, for Ornithischia
Length
3 mWikidata
Mass
450 kgWikidata

Time the record covers

At most 18 million years on record.

Every occurrence read is dated to somewhere between 83.6 Mya and 66 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Late Cretaceous — about 34 of 34 occurrencesLate CretaceousPaleocene — about 0 of 34 occurrences84–83 Mya — about 0.0 occurrences83–83 Mya — about 0.1 occurrences83–82 Mya — about 0.1 occurrences82–82 Mya — about 0.1 occurrences82–81 Mya — about 0.1 occurrences81–80 Mya — about 0.1 occurrences80–80 Mya — about 0.1 occurrences80–79 Mya — about 0.1 occurrences79–79 Mya — about 0.1 occurrences79–78 Mya — about 0.1 occurrences78–77 Mya — about 0.1 occurrences77–77 Mya — about 0.1 occurrences77–76 Mya — about 0.1 occurrences76–75 Mya — about 0.1 occurrences75–75 Mya — about 0.1 occurrences75–74 Mya — about 0.1 occurrences74–74 Mya — about 0.1 occurrences74–73 Mya — about 0.1 occurrences73–72 Mya — about 0.1 occurrences72–72 Mya — about 3 occurrences72–71 Mya — about 3 occurrences71–70 Mya — about 3 occurrences70–70 Mya — about 3 occurrences70–69 Mya — about 3 occurrences69–69 Mya — about 3 occurrences69–68 Mya — about 3 occurrences68–67 Mya — about 3 occurrences67–67 Mya — about 3 occurrences67–66 Mya — about 3 occurrences66–66 Mya — about 0.6 occurrences84.1 Mya65.5 Mya

34 occurrences of Pachycephalosaurus on record, most of them in the Late Cretaceous. 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

6 formations

Hell Creek — 47.70°N, 106.23°WHell Creek — 47.68°N, 106.43°WHell Creek — 47.88°N, 106.20°WHell Creek — 45.76°N, 104.95°WHell Creek — 46.35°N, 103.90°WHell Creek — 47.53°N, 106.92°WHell Creek — 45.85°N, 104.83°WHell Creek — 47.96°N, 106.46°WHell Creek — 47.60°N, 106.38°WHell Creek — 47.67°N, 106.30°WHell Creek — 45.10°N, 102.09°WHell Creek — 45.77°N, 104.93°WHell Creek — 47.05°N, 107.35°WHell Creek — 45.68°N, 105.08°WHell Creek — 45.00°N, 103.19°WLance — 45.67°N, 101.48°WLance — 43.12°N, 104.64°WLance — 43.15°N, 104.62°WLance — 43.44°N, 104.41°WLance — 43.38°N, 104.47°WLance — 45.10°N, 104.92°WLance — 43.49°N, 104.46°WFerris — 41.80°N, 107.00°WFerris — 41.94°N, 106.88°WDenver — 39.84°N, 105.04°WDinosaur Park — 50.74°N, 111.58°WScollard — 51.95°N, 112.94°W

Loading coastlines…

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

Pachycephalosaurus and its relatives

Late Cretaceous

Where Pachycephalosaurus and its relatives were recorded in the Late Cretaceous.

Found in the same rock

205 taxa

The Paleobiology Database records 32 sites for Pachycephalosaurus, 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

19 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. 7 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 content3

Picture of Pachycephalosaurus

Credit
IJReid
Licence
CC BY 4.0
Commercial use
the licence allows it

CT scan

Licence
not stated by the source
Commercial use
cannot be read from the licence given — check the record
Specimen
Pachycephalosaurus sp. · umnh:vp:18700

3D model

Source
Sketchfab
Credit
seirogan
Licence
CC Attribution
Commercial use
cannot be read from the licence given — check the record

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 itEupachycephalosauria through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Brown and Schlaikjer 1943