Mononykus
Mononykus is a genus of alvarezsaurid dinosaur that lived during the Late Cretaceous in what is now Mongolia, specifically the Nemegt Formation. Mononykus was a very small theropod, estimated around 1 to 1.2 metres in length with a weight of 3.5 kilograms (7.7 lb). As in Shuvuuia, Mononykus likely developed a shaggy feathering. It was lightly built with long, thin legs and highly reduced and specialized forelimbs that were likely used for foraging termite mounds or other insect colonies.

Jonathan Chen · CC BY-SA 4.0 · 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
- ParvicursorinaePBDB
- Diet
- carnivorePBDB, for Coelurosauria
- Life habit
- ground dwelling, solitaryPBDB, for Theropoda
- Motility
- actively mobilePBDB, for Theropoda
- Environment
- terrestrialPBDB, for Theropoda
- Length
- 1 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.
6 occurrences of Mononykus 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
2 formations
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The named rock units Mononykus has been recovered from, largest first. Drawn where the rock is now, not where it formed.
Mononykus and its relatives
Late CretaceousWhere Mononykus and its relatives were recorded in the Late Cretaceous.
Found in the same rock
46 taxa- Deinocheirus mirificus2 sites
- Lacertilia2 sites
- Sauropoda2 sites
- Tarbosaurus2 sites
- Tarbosaurus bataar2 sites
- Testudines2 sites
- Ankylosauria1 site
- Avimimus portentosus1 site
- Bagaceratops1 site
- Bivalvia1 site
- Brodavis mongoliensis1 site
- Carusia intermedia1 site
- Crocodylia1 site
- Dendroolithidae1 site
- Dinosauria1 site
- Dromaeosauridae1 site
- Elmisaurus1 site
- Elmisaurus rarus1 site
- Elongatoolithus1 site
- Estesia mongoliensis1 site
- Gallimimus1 site
- Gastropoda1 site
- Gobipteryx1 site
- Gobiraptor minutus1 site
The Paleobiology Database records 6 sites for Mononykus, 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- A new alvarezsaurid dinosaur from the Nemegt Formation of Mongolia1
- Report of the HMNS-MPC Joint Paleontological Expedition in 20061
- Report on the Japan–Mongolia Joint Paleontological Expedition to the Gobi desert, 19931
- Skeletal morphology of Mononykus olecranus (Theropoda: Avialae) from the Late Cretaceous of Mongolia1
- Flightless bird from the Cretaceous of Mongolia1
- Correction: Flightless bird from the Cretaceous of Mongolia1
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. 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 Mononykus
- Source
- Wikipedia/Commons
- Credit
- Jonathan Chen
- Licence
- CC BY-SA 4.0
- 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, “Mononykus”
- 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 itParvicursorinae through timeFormations of the Late CretaceousThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Perle et al. 1993