Saws, Scissors, and Sharks: Late Paleozoic Experimentation with Symphyseal Dentition

  title={Saws, Scissors, and Sharks: Late Paleozoic Experimentation with Symphyseal Dentition},
  author={Leif Tapanila and Jesse Pruitt and Cheryl A. D. Wilga and Alan Pradel},
  journal={The Anatomical Record},
Sharks of Late Paleozoic oceans evolved unique dentitions for catching and eating soft bodied prey. A diverse but poorly preserved clade, edestoids are noted for developing biting teeth at the midline of their jaws. Helicoprion has a continuously growing root to accommodate >100 crowns that spiraled on top of one another to form a symphyseal whorl supported and laterally braced within the lower jaw. Reconstruction of jaw mechanics shows that individual serrated crowns grasped, sliced, and… 
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Tail and whorl morphologies among the species are consistent with cranial anatomy observed in a juvenile E. heinrichi and with transverse tooth-wear patterns to suggest Edestus used a forward to backward slicing motion to bite its prey.
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Evolution & Development
Correspondence Nicholas A. Levis, Department of Biology, CB#3280, University of North Carolina, Chapel Hill, NC 27599. Email: Abstract Recent years have witnessed increased


An Abraded Tooth of Edestus (Chondrichthyes, Eugeneodontiformes): Evidence for a Unique Mode of Predation
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A Tooth Whorl of Edestus heinrichi (Chondrichthyes, Eugeneodontiformes) Displaying Progressive Macrowear
  • W. Itano
  • Biology
    Transactions of the Kansas Academy of Science
  • 2018
A partial tooth whorl of a different species, Edestus heinrichi, is described, and wear is observed to the serrations as well as to the apices of the crowns, which supports the recent hypothesis on the function of the toothwhorls.
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The reconstruction of Helicoprion illustrates novel adaptations, such as lateral cartilage to buttress the tooth whorl, which accommodated the unusual trait of continuous addition and retention of teeth in a predatory chondrichthyan.
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