Ectopterygoid

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Skull of the early reptile Milleretta rubidgei (Millerettidae), showing ectopterygoid on the underside of the skull (labeled ect, yellow, bottom right) Milleretta rubidgei (skull and reconstruction).png
Skull of the early reptile Milleretta rubidgei (Millerettidae), showing ectopterygoid on the underside of the skull (labeled ect, yellow, bottom right)

The ectopterygoid is a skull bone present in bony fish as well as many tetrapods. It forms part of the roof of the mouth, and plesiomorphically serves to connected the palate including the adjacent pterygoid bone with the braincase. [1] It is absent in living birds, but is present in dinosaurs and early birds like Archaeopteryx . [2] While retained in monotremes, it is absent in adult therian mammals, though its remnants can be seen early in foetus development. [3] In many early tetrapods, it bears teeth (palatal dentition), though these are lost in all synapsids and diapsid reptiles. [4]

References

  1. ↑ Holliday, Casey M.; Witmer, Lawrence M. (2009-09-12). "The epipterygoid of crocodyliforms and its significance for the evolution of the orbitotemporal region of eusuchians". Journal of Vertebrate Paleontology. 29 (3): 715–733. doi:10.1671/039.029.0330. ISSN   0272-4634.
  2. ↑ Mayr, Gerald (2022-09). "A survey of the uncinate bone and other poorly known ossicles associated with the lacrimal/ectethmoid complex of the avian skull". The Anatomical Record. 305 (9): 2312–2330. doi:10.1002/ar.24869. ISSN   1932-8486.{{cite journal}}: Check date values in: |date= (help)
  3. ↑ Presley, R.; Steel, F. L. D. (1978). "The pterygoid and ectopterygoid in mammals". Anatomy and Embryology. 154 (1): 95–110. doi:10.1007/BF00317957. ISSN   0340-2061.
  4. ↑ Matsumoto, Ryoko; Evans, Susan E. (January 2017). "The palatal dentition of tetrapods and its functional significance". Journal of Anatomy. 230 (1): 47–65. doi:10.1111/joa.12534. ISSN   0021-8782. PMC   5192890 . PMID   27542892.
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