Troodon formosus

Troodon is a controversial genus of relatively small, bird-like theropod dinosaurs definitively known from the Campanian age of the Late Cretaceous period. It includes at least one species, Troodon formosus, known from Montana. Discovered in October 1855, T. formosus was among the first dinosaurs found in North America, although it was thought to be a lizard until 1877.

Troodon formosus

Montanoceratops · 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
TroodonPBDB
Diet
carnivore, omnivorePBDB, for Troodontidae
Life habit
ground dwellingPBDB, for Troodontidae
Motility
actively mobilePBDB, for Theropoda
Environment
terrestrialPBDB, for Troodontidae

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 55 of 55 occurrencesLate CretaceousPaleocene — about 0 of 55 occurrences84–83 Mya — about 0.5 occurrences83–83 Mya — about 2 occurrences83–82 Mya — about 2 occurrences82–82 Mya — about 2 occurrences82–81 Mya — about 2 occurrences81–80 Mya — about 2 occurrences80–80 Mya — about 2 occurrences80–79 Mya — about 2 occurrences79–79 Mya — about 2 occurrences79–78 Mya — about 2 occurrences78–77 Mya — about 2 occurrences77–77 Mya — about 2 occurrences77–76 Mya — about 2 occurrences76–75 Mya — about 2 occurrences75–75 Mya — about 2 occurrences75–74 Mya — about 2 occurrences74–74 Mya — about 2 occurrences74–73 Mya — about 2 occurrences73–72 Mya — about 2 occurrences72–72 Mya — about 1 occurrence72–71 Mya — about 1 occurrence71–70 Mya — about 1 occurrence70–70 Mya — about 1 occurrence70–69 Mya — about 1 occurrence69–69 Mya — about 1 occurrence69–68 Mya — about 1 occurrence68–67 Mya — about 1 occurrence67–67 Mya — about 1 occurrence67–66 Mya — about 1 occurrence66–66 Mya — about 0.2 occurrences84.1 Mya65.5 Mya

55 occurrences of Troodon formosus 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

55 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

8 formations

Dinosaur Park — 49.12°N, 110.47°WDinosaur Park — 50.75°N, 111.48°WDinosaur Park — 50.75°N, 111.50°WDinosaur Park — 50.79°N, 111.62°WDinosaur Park — 50.75°N, 111.40°WDinosaur Park — 49.99°N, 111.42°WDinosaur Park — 50.73°N, 111.30°WDinosaur Park — 50.72°N, 111.56°WOldman — 50.75°N, 111.51°WOldman — 49.08°N, 110.68°WOldman — 49.16°N, 110.72°WOldman — 50.83°N, 111.32°WOldman — 49.28°N, 112.58°WOldman — 50.72°N, 111.40°WOldman — 50.79°N, 111.62°WOldman — 49.28°N, 112.20°WJudith River — 46.47°N, 109.30°WJudith River — 46.46°N, 109.41°WJudith River — 47.81°N, 109.59°WJudith River — 46.10°N, 109.10°WJudith River — 46.40°N, 109.66°WJudith River — 47.77°N, 108.95°WJudith River — 47.72°N, 109.64°WJudith River — 43.64°N, 109.35°WTwo Medicine — 48.63°N, 113.75°WTwo Medicine — 48.65°N, 112.97°WTwo Medicine — 47.81°N, 112.18°WTwo Medicine — 47.82°N, 112.66°WTwo Medicine — 48.94°N, 112.64°WPrince Creek — 70.07°N, 151.58°WPrince Creek — 69.60°N, 151.80°WPrince Creek — 70.09°N, 151.54°WPrince Creek — 69.83°N, 151.52°WFerris — 41.94°N, 106.85°WFerris — 41.95°N, 106.89°WKakanaut — 62.87°N, 177.07°EHorseshoe Canyon — 51.48°N, 112.77°W

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

Troodon formosus and its relatives

Late Cretaceous

Where Troodon formosus and its relatives were recorded in the Late Cretaceous.

Found in the same rock

288 taxa

The Paleobiology Database records 54 sites for Troodon formosus, 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

24 references

Each of the 55 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. 12 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 content2

Picture of Troodon formosus

Credit
Montanoceratops
Licence
CC0
Commercial use
the licence allows it

Structured light scan

Licence
not stated by the source
Commercial use
cannot be read from the licence given — check the record
Specimen
Troodon formosus · mor:MOR 553S 8-8-92-188

Smithsonian Open Access was 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 itTroodon through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Leidy 1856