Haootia

Haootia
Temporal range: Late Ediacaran,
Life restoration from McIlroy et al., 2024
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Staurozoa
Genus: Haootia
Liu et al., 2014
Species:
H. quadriformis
Binomial name
Haootia quadriformis
Liu et al., 2014

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.