Fauna
Invertebrate

Hyolithes carinatus

Hyolithes carinatus

Haplophrentis carinatus was an abundant, shell-bearing Cambrian animal that rested on muddy seafloors, propping and stabilizing itself with two curved lateral spines called helens. Exquisite soft-tissue preservation from the Burgess Shale revealed a retractable, tentacle-bearing feeding organ, clarifying its evolutionary relationship to modern lophophorates like brachiopods. Shells commonly turn up stacked inside the fossilized digestive tracts of priapulid worms, offering a remarkable record of early Paleozoic predation.

CambrianBenthic
—observations
—countries
—peak records
ExtinctConservation statusIUCN Red List categoriesLCNTVUENCREWEXExtinctRed List categories, explained →
Diet & preyOrganic detritus, Phytoplankton
Predators
  • Priapulid worms (Ottoia prolifica)
  • Anomalocaridids
ThreatsPriapulid worm predation and Cambrian marine turnover
HabitatsCambrian shallow marine seafloors
Life spanEstimated 1–3 years
  1. FamilyHyolithidae
  2. SpeciesHyolithes carinatus
Range data is not available yet.
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Safe to observe at a normal distance.
Responsible observation
  • Fossil Observation: Inspect shale slabs under low-angle cross-light to highlight subtle relief in the operculum and helens.
  • Museum Collections: Search for specimens preserved directly within fossilized digestive tracts of Burgess Shale worms.
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