Haootia quadriformis
Haootia quadriformis is an extinct animal belonging to the Ediacaran biota. Estimated to be about 560 million years old, H. quadriformis is identified as a cnidarian polyp, and represents the earliest known evidence for muscle tissue in an animal. Discovered in 2008 from Newfoundland in eastern Canada, it was formally described in 2014. It is the first Ediacaran organism discovered to show fossils of muscle fibres. Structural examination of the muscles and morphology indicate that the animal is a cnidarian, though, which class H. quadriformis belongs to was undetermined until a 2024 study found it to be a staurozoan.

D McIlroy, G Pasinetti, D Pérez-Pinedo, C McKean, S C Dufour, J J Matthews, L R Menon, R Nicholls, R S Taylor · CC BY 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
- HaootiaPBDB
Time the record covers
At most 97 million years on record.
Every occurrence read is dated to somewhere between 635 Mya and 538.8 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.
2 occurrences of Haootia quadriformis on record. 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
2 occurrencesThese 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
- Fermeuse Formation1
- Trepassey Formation · St. Johns Group1
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The named rock units Haootia quadriformis has been recovered from, largest first. Drawn where the rock is now, not where it formed.
Found in the same rock
5 taxa- Aspidella terranovica1 site
- Bradgatia1 site
- Charniodiscus1 site
- Primocandelabrum1 site
- Vinlandia1 site
The Paleobiology Database records 2 sites for Haootia quadriformis, and this reads all of them. The number is how many of those sites it was catalogued from too.
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
1 referenceEach of the 2 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 doi.org. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.
Media and terms
Media content2
Picture of Haootia quadriformis
- Source
- Wikipedia/Commons
- Credit
- D McIlroy, G Pasinetti, D Pérez-Pinedo, C McKean, S C Dufour, J J Matthews, L R Menon, R Nicholls, R S Taylor
- Licence
- CC BY 4.0
- Commercial use
- the licence allows it
3D model
- Source
- Sketchfab
- Licence
- CC Attribution-NonCommercial
- Commercial use
- the licence does not allow 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, “Haootia”
- 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 itHaootia through time
Occurrence data from the Paleobiology Database, CC BY 4.0. Liu et al. 2014