Research ArticlePALEONTOLOGY

The earliest herbivorous marine reptile and its remarkable jaw apparatus

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Science Advances  06 May 2016:
Vol. 2, no. 5, e1501659
DOI: 10.1126/sciadv.1501659


  • Fig. 1 Prepared skulls referred to the Middle Triassic marine reptile A. unicus.

    (A) IVPP V20291 exposed in dorsal view. (B) IVPP V20292 exposed in ventral view. Scale bar, 2.0 cm. [Photo Credit: W. Gao, Institute of Vertebrate Paleontology and Paleoanthropology]

  • Fig. 2 Interpretative drawings of the skulls of A. unicus.

    (A) IVPP V20291 in dorsal view. (B) IVPP V20292 in ventral view, with detail of the shagreen of palatal teeth highlighted. a, angular; ar, articular; at, atlas; ax, axis; cr, cervical rib; cv, cervical vertebra; d, dentary; ect, ectopterygoid; f, frontal; hy, hyoid; in, internal naris; j, jugal; mx, maxilla; n, nasal; p, parietal; pal, palatine; pf, postfrontal; pm, premaxilla; po, postorbital; prf, prefrontal; pt, pterygoid; q, quadrate; sa, surangular; sp, splenial; sq, squamosal; v, vomer. [Illustration: X. Guo, Institute of Vertebrate Paleontology and Paleoanthropology]

  • Fig. 3 Artist’s restoration of A. unicus depicting it as a herbivore grazing on marine plants growing on a hard substrate in the eastern Tethyan Sea during Middle Triassic times.

    Using batteries of spatulate teeth lining the hammerhead expansions of both the upper and lower jaws, it would have been able to scrape off numerous pieces of plant matter into suspension in the water. This could then be sucked in and filtered by the long, thin, and closely packed needle-shaped teeth lining the main jaw rami. [Illustration: Y. Chen, Institute of Vertebrate Paleontology and Paleoanthropology]

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