Thermal Regulation in Sail Lizards

@article{Bramwell1973ThermalRI,
  title={Thermal Regulation in Sail Lizards},
  author={Cherrie D. Bramwell and Peter Fellgett},
  journal={Nature},
  year={1973},
  volume={242},
  pages={203-205}
}
THE extinct Order Pelycosauria contained several genera of reptiles characterized by extreme elongation of the neural spines of the vertebrae, which in life supported an area of membrane forming a “sail”1–3. Dimetrodon grandis was the end form of an evolutionary series of pelycosaurs that had tended to develop increasingly large sails2. Many suggestions have been made about the function of the sail, as camouflage among reeds while it waited for prey, for sexual display, or literally as a sail… 

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References

SHOWING 1-2 OF 2 REFERENCES

Notes on the Permo-Carboniferous Reptile Dimetrodon

  • A. Romer
  • Chemistry
    The Journal of Geology
  • 1927
1. A nearly complete postcranial skeleton of the Permo-Carboniferous reptile Dimetrodon is described and figured. The structure and possible function of the spines are discussed, and a mechanical