Brachychampsa
Brachychampsa is an extinct genus of alligatorid, possibly a basal caiman. Specimens have been reported from New Mexico, Colorado, Wyoming, Montana, North and South Dakota, New Jersey, and Saskatchewan, though only those from Montana, Utah, and New Mexico are based on material sufficient to justify the referral. Some specimens have been reported from the Campanian-aged deposits of Central Asia, although the species status is indeterminate for these fossils. The genus first appeared during the late Campanian stage of the Late Cretaceous and became extinct during the late Maastrichtian stage of the Cretaceous. Brachychampsa is distinguished by an enlarged fifth maxillary tooth in the upper jaw.
Daderot · 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
- BrachychampsiniPBDB
- Diet
- carnivorePBDB
- Life habit
- amphibiousPBDB
- Motility
- actively mobilePBDB, for Osteichthyes
- Environment
- freshwaterPBDB
Time the record covers
At least 23 million years on record.
The record covers at least 89.8 Mya to 66 Mya. No occurrence read is dated outside 93.9 Mya to 63.4 Mya.
131 occurrences of Brachychampsa 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
131 occurrences- Late Cretaceous99%
- Paleoceneunder 1%
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
19 formations
- Hell Creek Formation · Montana Group65
- Lance Formation22
- Ferris Formation17
- Aguja Formation5
- Fruitland Formation4
- Kirtland Formation3
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The named rock units Brachychampsa 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.
Brachychampsa and its relatives
Late CretaceousWhere Brachychampsa and its relatives were recorded in the Late Cretaceous.
Found in the same rock
552 taxa- Trionychidae76 sites
- Myledaphus bipartitus64 sites
- Lepisosteus occidentalis63 sites
- Borealosuchus sternbergii59 sites
- Cyclurus fragosus55 sites
- Champsosaurus49 sites
- Baenidae48 sites
- Ceratopsidae48 sites
- Scapherpeton tectum47 sites
- Compsemys victa46 sites
- Lonchidion selachos46 sites
- Adocus37 sites
- Theropoda37 sites
- Paronychodon36 sites
- Hadrosaurinae33 sites
- Chelydridae32 sites
- Cimolodon nitidus32 sites
- Lepisosteidae31 sites
- Meniscoessus robustus31 sites
- Hadrosauridae29 sites
- Habrosaurus dilatus28 sites
- Richardoestesia isosceles28 sites
- Opisthotriton kayi27 sites
- Tyrannosauridae27 sites
The Paleobiology Database records 128 sites for Brachychampsa, 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
37 references- Fossil Vertebrate Collections25
- Vertebrate biostratigraphy of the Hell Creek Formation in southwestern North Dakota and northwestern South Dakota25
- Vertebrate faunal changes through Lancian and Puercan time in southern Wyoming18
- Fossil vertebrates from the Late Cretaceous Lance Formation, eastern Wyoming16
- Patterns of geographic variation in latest Cretaceous vertebrates: evidence from the turtle component6
- Vertebrate paleoecology from microsites, Talley Mountain, Upper Aguja Formation (Late Cretaceous), Big Bend National Park, Texas, USA5
- Microvertebrados Cretácicos Tardíos del Área de El Rosario, Baja California, México [Late Cretaceous microvertebrates from the El Rosario area, Baja California, Mexico]2
- Stratigraphy and paleontology of the Cretaceous Hell Creek Formation, Stumpf site, Morton County, North Dakota2
- An aniliid snake and associated vertebrates from the Campanian of New Mexico2
- The Lower Vertebrates of the Hell Creek Formation, Harding County, South Dakota2
- Lower vertebrates from the Late Cretaceous Hell Creek Formation, McCone County, Montana2
- Brachychampsa montana Gilmore (Crocodylia, Alligatoroidea) from the Kirtland Formation (upper Campanian), San Juan Basin, New Mexico1
Each of the 131 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. 25 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 Brachychampsa
- Source
- Wikipedia/Commons
- Credit
- Daderot
- Licence
- CC0
- Commercial use
- the licence allows it
CT scan
- Source
- MorphoSource
- Licence
- not stated by the source
- Commercial use
- cannot be read from the licence given — check the record
- Specimen
- Brachychampsa sp. · UCMP:V:159000
3D model
- Source
- Sketchfab
- Licence
- CC Attribution-NonCommercial
- Commercial use
- the licence does not allow it
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 itBrachychampsini through timeFormations of the Late CretaceousThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Gilmore 1911