Fauna
Species

Haikouichthys ercaicunensis

Haikouichthys ercaicunensis

Haikouichthys ercaicunensis swam through early Cambrian shallow seas using rhythmic contractions of zigzag-shaped muscle segments known as myomeres. Measuring barely an inch long, this slender creature possessed a distinct head, eyes, and primitive gill structures supported by a cartilaginous braincase. Its streamlined form and defined fin folds marked the groundbreaking evolutionary debut of the vertebrate body plan over half a billion years ago.

PrehistoricCambrian
—observations
—countries
—peak records
ExtinctConservation statusIUCN Red List categoriesLCNTVUENCREWEXExtinctRed List categories, explained →
Diet & preyPhytoplankton, Marine detritus, Microbial mats
Predators
  • Anomalocaris saron
  • Amplectobelua symbrachiata
ThreatsNatural evolutionary pressures and ancient oceanographic changes (extinct)
HabitatsShallow marine shelf seas and muddy seafloors
Life spanUnknown
  1. FamilyMyllokunmingiidae
  2. SpeciesHaikouichthys ercaicunensis
Range data is not available yet.
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Extinct prehistoric species; known exclusively from the fossil record.
Responsible observation
  • Fossil Identification: Look for dark carbonaceous films showing zigzag muscle blocks on fine-grained shale.
  • Museum Viewing: Observe specimens under low-angle directional light to discern delicate head structures and gill pouches.
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