Cimoliasaurus magnus
Cimoliasaurus was a plesiosaur that lived during the Late Cretaceous (Maastrichtian) of the eastern United States, with fossils known from New Jersey, North Carolina, and Maryland.

Leidy · 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
- CimoliasaurusPBDB
- Diet
- carnivorePBDB, for Plesiosauria
- Life habit
- aquatic, depth=surfacePBDB, for Plesiosauria
- Motility
- actively mobilePBDB, for Plesiosauria
- Environment
- marinePBDB, for Plesiosauria
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.
6 occurrences of Cimoliasaurus magnus 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
6 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
3 formations
- Navesink Formation · Monmouth Group3
- Severn Formation2
- New Egypt Formation · Monmouth Group1
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The named rock units Cimoliasaurus magnus has been recovered from, largest first. Drawn where the rock is now, not where it formed.
Cimoliasaurus magnus and its relatives
Late CretaceousWhere Cimoliasaurus magnus and its relatives were recorded in the Late Cretaceous.
Found in the same rock
125 taxa- Peritresius ornatus4 sites
- Ischyrhiza mira3 sites
- Mosasauridae3 sites
- Mosasaurus hoffmannii3 sites
- Squalicorax kaupi3 sites
- Carcharias samhammeri2 sites
- Chiloscyllium greeni2 sites
- Cretalamna appendiculata2 sites
- Enchodus ferox2 sites
- Hadrosauridae2 sites
- Halisaurus platyspondylus2 sites
- Heterodontus2 sites
- Mosasaurus2 sites
- Mosasaurus conodon2 sites
- Odontaspis aculeatus2 sites
- Osteopygis emarginatus2 sites
- Pantrionychidae2 sites
- Paralbula casei2 sites
- Ptychotrygon vermiculata2 sites
- Squalicorax pristodontus2 sites
- Squatina (Cretascyllium) hassei2 sites
- Testudines2 sites
- Texatrygon avonicola2 sites
- Thoracosaurus neocesariensis2 sites
The Paleobiology Database records 6 sites for Cimoliasaurus magnus, 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
6 references- Vertebrate Paleontology and Stratigraphy of the Late Cretaceous Holmdel Park Site, Monmouth County, New Jersey1
- A Late Cretaceous (Severn Formation) Vertebrate Assemblage from Bowie, Maryland1
- The Cretaceous/Tertiary mass extinction event in the North Atlantic coastal plain1
- Upper Cretaceous reptiles from the Severn Formation of Maryland1
- Paleontology, biostratigraphy, and depositional environments of the Cretaceous-Tertiary transition in the New Jersey coastal plain1
- Additional records of plesiosaurs from the Cretaceous of New Jersey1
Each of the 6 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. Each entry links to the Paleobiology Database's own record for the work.
Media and terms
Media content1
Picture of Cimoliasaurus magnus
- Source
- Wikipedia/Commons
- Credit
- Leidy
- Licence
- Public Domain
- Commercial use
- the licence allows it
No 3D scan of Cimoliasaurus magnus was found in Sketchfab.
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
- 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 itCimoliasaurus through timeFormations of the Late CretaceousThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. (Leidy 1851)