Research ArticleEVOLUTIONARY BIOLOGY

High-performance suction feeding in an early elasmobranch

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Science Advances  11 Sep 2019:
Vol. 5, no. 9, eaax2742
DOI: 10.1126/sciadv.aax2742
  • Fig. 1 T. arcuatus cranial skeleton.

    (A) Dorsal, (B) ventral, (C) left lateral, and (D) anterior dorsolateral views; contributing specimens in table S1. (E) Carboniferous-Permian elasmobranch time-calibrated phylogeny, simplified after (16) (boundary ages from Chronostratigraphic Chart ICS V.2018/8); red bars mark earliest gape-limited expanding jaw systems: Acentrophorus (6), earliest actinopterygian with mobile maxilla. adf, adductor fossa; chb, ceratohyal blade; hm, hyomandibula; hr, hyoid rays; lbc, labial cartilage chain; lve, lateroventral extremity of palatoquadrate; mc, Meckel’s cartilage; os, otic shelf; pal, palatine process; pnl, postnasal lamina; ppr, postorbital process; qu, quadrate; rap, retroarticular process.

  • Fig. 2 Symmoriid and T. arcuatus crania: contrasting jaw shapes, adductor muscle areas, and hyoid orientations.

    (A to C) Symmoriid right lateral view and (D to F) Tristychius left lateral view, neurocranium, hyoid arch, and jaws in articulation. Pink areas indicate estimates of jaw muscle distribution. (G) Tristychius feeding apparatus (black) and muscles (red) reconstructed; myosepta shown for segmented muscles, adapted from (24). (H) Symmoriid and (I) Tristychius crania with jaws open. bhy, basihyal; chy, ceratohyal; hhy, hypohyal; jj, jaw joint; lcr, lateral crest; pdr, posterodorsal rim.

  • Fig. 3 Mouth opening and closing sequence.

    (A) Reconstructed coordinated cranial cartilage motions and estimates of oral volume through mouth opening and closing cycle. (B) Closed mouth. (C) Mouth fully open with Meckel’s cartilage depressed. (D) Mouth closing with hyoid bar fully depressed. (E) Mouth closing with hyoid bar elevated. Vertical bars, extending from oral volume estimates, show maximum variance (table S2).

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/5/9/eaax2742/DC1

    Fig. S1. Tristychius arcuatus, renderings of key specimens.

    Fig. S2. Mandibular arch cartilages of T. arcuatus.

    Fig. S3. Hyoid arch and pectoral girdle of T. arcuatus.

    Fig. S4. T. arcuatus: physical model showing interconnected 3D four-bar linkages.

    Fig. S5. The cranial skeleton of a juvenile Chiloscyllium punctatum reconstructed from high-resolution computed tomography.

    Fig. S6. Conformations of the skull of T. arcuatus.

    Fig. S7. Filtering the dataset of T. arcuatus cranial conformations.

    Fig. S8. Morphospace for early gnathostomes relative to jaw measurement characters from Anderson et al. (36).

    Fig. S9. Life restoration of T. arcuatus from the Viséan Wardie Shales of Edinburgh, Scotland.

    Table S1. T. arcuatus specimens contributing to study.

    Table S2. Measurements of oral volume (milliliters) from physical model of T. arcuatus.

    Table S3. Additions to Anderson et al. (36) dataset of mandible metrics.

    Movie S1. Jaw and hyoid motion sequences modeled in caudal view.

    Movie S2. Jaw and hyoid motion sequences modeled in cranial view.

    Movie S3. Jaw and hyoid motion sequences modeled in dorsal view.

    Movie S4. Jaw and hyoid motion sequences modeled in lateral view.

    Movie S5. Jaw and hyoid motion sequences modeled in ventral view.

    Movie S6. Animation of complete cranial to pectoral skeleton opening and closing jaws, ingesting prey.

    References (6877)

  • Supplementary Materials

    The PDF file includes:

    • Fig. S1. Tristychius arcuatus, renderings of key specimens.
    • Fig. S2. Mandibular arch cartilages of T. arcuatus.
    • Fig. S3. Hyoid arch and pectoral girdle of T. arcuatus.
    • Fig. S4. T. arcuatus: physical model showing interconnected 3D four-bar linkages.
    • Fig. S5. The cranial skeleton of a juvenile Chiloscyllium punctatum reconstructed from high-resolution computed tomography.
    • Fig. S6. Conformations of the skull of T. arcuatus.
    • Fig. S7. Filtering the dataset of T. arcuatus cranial conformations.
    • Fig. S8. Morphospace for early gnathostomes relative to jaw measurement characters from Anderson et al. (36).
    • Fig. S9. Life restoration of T. arcuatus from the Viséan Wardie Shales of Edinburgh, Scotland.
    • Table S1. T. arcuatus specimens contributing to study.
    • Table S2. Measurements of oral volume (milliliters) from physical model of T. arcuatus.
    • Table S3. Additions to Anderson et al. (36) dataset of mandible metrics.
    • Legends for movies S1 to S6
    • References (6877)

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • Movie S1 (.mov format). Jaw and hyoid motion sequences modeled in caudal view.
    • Movie S2 (.mov format). Jaw and hyoid motion sequences modeled in cranial view.
    • Movie S3 (.mov format). Jaw and hyoid motion sequences modeled in dorsal view.
    • Movie S4 (.mov format). Jaw and hyoid motion sequences modeled in lateral view.
    • Movie S5 (.mov format). Jaw and hyoid motion sequences modeled in ventral view.
    • Movie S6 (.mp4 format). Animation of complete cranial to pectoral skeleton opening and closing jaws, ingesting prey.

    Files in this Data Supplement:

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