A sourced illustration has not yet been added. This gap is included in the coverage record.

Overview

Marrella splendens reached about 25 mm long. Its headshield bore long paired spines and two pairs of head appendages, the second pair paddle-like. The trunk had 26 limb-bearing segments, and inner spines toward the rear formed a net-like arrangement.

Swimming, deposit feeding and suspension feeding have been proposed from its anatomy; these are reconstructions, not observed behaviour. Royal Ontario Museum specimen ROM 56781 preserves moulting, and later researchers cite a Marrella moult as directly preserved behaviour. Copper-rich stains once read as blood proteins were later attributed to metamorphism.

Walcott's notebook includes a sketch dated 31 August 1909. The lectotype is Smithsonian specimen USNM 57674. Its placement in Marrellida is accepted, but that group's broader relationships remain disputed.

Paired spinesSegmented trunkPaddle-like appendages
01

Origins & earliest records

Walcott formally described it in 1912.

02

Evidence & interpretation

Body fossils and a preserved moult.

Selected bibliography

Documented works and useful reading. This is not a list of every appearance.

  1. 01

    Marrella splendens

    Royal Ontario Museum · n.d.

    Selected bibliography; museum account read: taxonomy, age, research history, description, ecology.

  2. 02

    Moulting arthropod caught in the act

    García-Bellido & Collins · 2004

    Selected bibliography; bibliographic record only (Nature 429:40, DOI 10.1038/429040a); paper not read.

  3. 03

    Demecology in the Cambrian: synchronized molting in arthropods from the Burgess Shale

    Haug, Caron & Haug · 2013

    Selected bibliography; only the Background paragraph citing Marrella is used.

Family, evolution & connections

Taxonomic classification

A hierarchy of classified groups, not a chain of direct ancestors.

Source note: Marrellida's relationships within arthropods remain disputed.

  1. kingdomAnimalia
  2. phylumArthropoda
  3. orderMarrellida
  4. genusMarrella

References

Sources supporting this profile. Linked pages have their own scope and editorial standards.

  1. museummarrella splendensResearch access: 2026-10-06
  2. bibliographic recordMoulting arthropod caught in the actResearch access: 2026-10-06
  3. journal articleDemecology in the Cambrian: synchronized molting in arthropods from the Burgess ShaleResearch access: 2026-10-06

Image credits

A sourced illustration has not yet been added. This gap is included in the coverage record.

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