Research ArticleORGANISMAL BIOLOGY

Suspension feeding in the enigmatic Ediacaran organism Tribrachidium demonstrates complexity of Neoproterozoic ecosystems

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Science Advances  27 Nov 2015:
Vol. 1, no. 10, e1500800
DOI: 10.1126/sciadv.1500800
  • Fig. 1 Morphology and digital reconstruction of T. heraldicum.

    (A) Tribrachidium specimen N3993/5056 from the Ediacaran (~555 Ma) White Sea area of Russia. (B) Tribrachidium specimen SAM P12889 (paratype) from the Ediacaran of South Australia (Flinders Ranges). (C and D) Digital reconstruction of a latex cast of Tribrachidium specimen (020N-033W-TBE) from the Ediacaran of South Australia (Flinders Ranges), in upper (C) and angled (D) views. AP, apical pit; B, bulla; PB, primary branch; SB, secondary branch; TF, tentacular fringe. Scale bars, 10 mm.

  • Fig. 2 CFD simulations.

    (A to R) Details of water flow around Tribrachidium oriented at 0° (A to F) and 240° (G to L) to the current, and a smooth, unornamented hemisphere (null model) (M to R). Results visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude), in upper (A to C, G to I, and M to O) and lateral (D to F, J to L, and P to R) views. The ambient flow is from left to right.

  • Fig. 3 CFD simulations.

    (A to R) Details of water flow around Tribrachidium oriented at 0° to the current. Model with original height (A to F), double height (G to I), and half height (M to O). Results visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude), in upper (A to C, G to I, and M to O) and lateral (D to F, J to L, and P to R) views. The ambient flow is from left to right.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/1/10/e1500800/DC1

    Fig. S1. Computational domain for CFD simulations.

    Fig. S2. Results of CFD simulations with Tribrachidium oriented at 0° to the current, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).

    Fig. S3. Results of CFD simulations with Tribrachidium oriented at 120° to the current, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).

    Fig. S4. Results of CFD simulations with Tribrachidium oriented at 240° to the current, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).

    Fig. S5. Results of CFD simulations with the null model, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).

    Fig. S6. Comparison of the CFD simulations with different mesh sizes, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).

    Model S1. Digital reconstruction of Tribrachidium in IGES format.

  • Supplementary Materials

    This PDF file includes:

    • Fig. S1. Computational domain for CFD simulations.
    • Fig. S2. Results of CFD simulations with Tribrachidium oriented at 0° to the current, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).
    • Fig. S3. Results of CFD simulations with Tribrachidium oriented at 120° to the current, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).
    • Fig. S4. Results of CFD simulations with Tribrachidium oriented at 240° to the current, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).
    • Fig. S5. Results of CFD simulations with the null model, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).
    • Fig. S6. Comparison of the CFD simulations with different mesh sizes, visualized as two-dimensional plots of flow velocity magnitude with flow vectors (gray arrows; length of arrows proportional to the natural logarithm of the flow velocity magnitude).

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    Other Supplementary Material for this manuscript includes the following:

    • Model S1 (.igs format ). Digital reconstruction of Tribrachidium in IGES format.

    Files in this Data Supplement:

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