Chamops

Chamops is an extinct genus of polyglyphanodontian lizard from the Late Cretaceous-Early Eocene of North America. Fossils have been found in the Hell Creek Formation, Judith River Formation and Polecat Bench Formation of Montana, the Milk River Formation of Alberta, Canada and possibly also the Laramie Formation of Colorado. It is known from only one species, C. segnis. Unlike other polyglyphanodonts, Chamops had a more blunt snout. Chamops belonged to the Chamopsiid family of polyglyphanodontian lizards that lived in the Northern Hemisphere during the Late Cretaceous, although there are some possible Chamopsiid genera from South America and the Kem Kem Bone Beds in Morocco. It was originally thought Chamops and kin are related to whiptails, although it is now thought they are more closely related to iguanas.

Chamops

Othniel Charles Marsh (1831-1889) · Public Domain · via Wikidata/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
ChamopsiidaePBDB
Motility
actively mobilePBDB, for Osteichthyes
Environment
terrestrialPBDB, for Amniota

Time the record covers

At least 32 million years on record.

The record covers at least 89.8 Mya to 57.5 Mya. No occurrence read is dated outside 93.9 Mya to 56 Mya.

Late Cretaceous — about 32 of 33 occurrencesLate CretaceousPaleocene — about 1 of 33 occurrencesPaleoceneEocene — about 0 of 33 occurrences95–93 Mya — about 0.1 occurrences93–92 Mya — about 0.3 occurrences92–91 Mya — about 0.3 occurrences91–89 Mya — about 0.2 occurrences87–85 Mya — about 0.2 occurrences85–84 Mya — about 1 occurrence84–83 Mya — about 1.0 occurrences83–82 Mya — about 0.8 occurrences82–80 Mya — about 0.8 occurrences80–79 Mya — about 0.8 occurrences79–78 Mya — about 0.8 occurrences78–76 Mya — about 0.8 occurrences76–75 Mya — about 0.8 occurrences75–74 Mya — about 0.8 occurrences74–72 Mya — about 0.8 occurrences72–71 Mya — about 4 occurrences71–70 Mya — about 5 occurrences70–68 Mya — about 5 occurrences68–67 Mya — about 5 occurrences67–66 Mya — about 4 occurrences58–57 Mya — about 0.6 occurrences57–55 Mya — about 0.4 occurrences89.8 Mya57.5 Mya94.7 Mya55.2 Mya

33 occurrences of Chamops 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

33 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

11 formations

Lance — 43.12°N, 104.64°WLance — 41.57°N, 108.67°WLance — 43.18°N, 104.53°WLance — 43.15°N, 104.57°WLance — 43.13°N, 104.49°WLance — 43.80°N, 104.62°WLance — 43.24°N, 104.29°WLance — 42.76°N, 104.43°WHell Creek — 47.80°N, 106.10°WHell Creek — 47.55°N, 107.13°WHell Creek — 47.57°N, 107.10°WHell Creek — 47.52°N, 106.40°WHell Creek — 45.50°N, 103.10°WHell Creek — 45.64°N, 103.49°WKaiparowits — 37.40°N, 111.20°WKaiparowits — 37.42°N, 111.77°WKaiparowits — 37.80°N, 111.50°WWahweap — 37.59°N, 112.90°WWahweap — 37.63°N, 112.12°WFrenchman — 49.30°N, 108.40°WScollard — 51.91°N, 112.97°WMilk River — 49.10°N, 111.80°WAguja — 29.10°N, 103.17°WFort Union — 45.20°N, 109.00°WStraight Cliffs — 37.49°N, 111.89°WKirtland — 36.31°N, 108.05°W

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

Chamops and its relatives

Late Cretaceous

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

Found in the same rock

426 taxa

The Paleobiology Database records 32 sites for Chamops, 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

16 references

Each of the 33 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. 4 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 Chamops

Credit
Othniel Charles Marsh (1831-1889)
Licence
Public Domain
Commercial use
the licence allows it

No 3D scan of Chamops was found in MorphoSource and Sketchfab.

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 itChamopsiidae through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Marsh 1892