Alamosaurus
Alamosaurus is a genus of titanosaurian sauropod dinosaurs containing a single known species, Alamosaurus sanjuanensis, from the Maastrichtian age of the Late Cretaceous period in what is now southwestern North America. It is one of the only known sauropods to have inhabited North America after the nearly 30-million-year absence of sauropods from the continent's fossil record and probably represents an immigrant from South America or Asia.

Charles W. Gilmore · Public Domain · 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
- SaltasaurinaePBDB
- Diet
- herbivorePBDB, for Sauropoda
- Life habit
- ground dwelling, gregariousPBDB, for Sauropoda
- Motility
- actively mobilePBDB, for Sauropoda
- Environment
- terrestrialPBDB, for Sauropoda
- Length
- 21 mWikidata
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.
38 occurrences of Alamosaurus 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
38 occurrences- Late Cretaceous100%
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
- Ojo Alamo Formation15
- Javelina Formation · Tornillo Group9
- North Horn Formation4
- Kirtland Formation4
- Black Peaks Formation · Tornillo Group1
- McRae Formation1
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The named rock units Alamosaurus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 2 occurrences have no formation on record, which is common for older literature.
Alamosaurus and its relatives
Late CretaceousWhere Alamosaurus and its relatives were recorded in the Late Cretaceous.
Found in the same rock
51 taxa- Dinosauria5 sites
- Ceratopsidae4 sites
- Trionychidae4 sites
- Ankylosauria3 sites
- Hadrosauridae3 sites
- Ojoceratops fowleri3 sites
- Testudines3 sites
- Theropoda3 sites
- Adocidae2 sites
- Ankylosauridae2 sites
- Caenagnathidae2 sites
- Compsemys2 sites
- Continuoolithus canadensis2 sites
- Glyptodontopelta mimus2 sites
- Prismatoolithus jenseni2 sites
- Tyrannosauridae2 sites
- Viviparus2 sites
- Alnus1 site
- Anacolosidites1 site
- Baenidae1 site
- Brachychampsa montana1 site
- Ceratopsia1 site
- Chamops1 site
- Charophyta1 site
The Paleobiology Database records 38 sites for Alamosaurus, 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- Taxonomic composition of the Alamo Wash local fauna from the Upper Cretaceous Ojo Alamo Formation (Naashoibito Member), San Juan Basin, New Mexico5
- The sauropod dinosaur Alamosaurus from the Upper Cretaceous of the San Juan Basin, New Mexico.5
- Lehman, 19854
- The first giant titanosaurian sauropod from the Upper Cretaceous of North America3
- A juvenile specimen of the sauropod dinosaur Alamosaurus sanjuanensis from the Upper Cretaceous of Big Bend National Park, Texas3
- Reptilian fauna of the North Horn Formation of central Utah3
- Attributes of the ceratopsian dinosaur Torosaurus, and new material from the Javelina Formation (Maastrichtian) of Texas2
- The teeth of Alamosaurus sanjuanensis, a Late Cretaceous sauropod2
- A giant tyrannosaur from the Campanian–Maastrichtian of southern North America and the evolution of tyrannosaurid gigantism1
- Dinosaurs from the Late Cretaceous of the Ojinaga Basin in Northeastern Chihuahua, Mexico1
- A sauropod dinosaur pes from the latest Cretaceous of North America and the validity of Alamosaurus sanjuanensis (Sauropoda, Titanosauria)1
- Stratigraphy and vertebrate biostratigraphy across the Cretaceous-Tertiary boundary, Betonnie Tsosie Wash, San Juan Basin, New Mexico1
Each of the 38 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 content2
Picture of Alamosaurus
- Source
- Wikipedia/Commons
- Credit
- Charles W. Gilmore
- Licence
- Public Domain
- Commercial use
- the licence allows it
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
- Source
- Wikipedia, “Alamosaurus”
- 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 itSaltasaurinae through timeFormations of the Late CretaceousThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Gilmore 1922