Sphenopalatine vacuities

In rodents, sphenopalatine vacuities are perforations of the roof of the mesopterygoid fossa, the open space behind the palate, in between the parapterygoid fossae.[1] They may perforate the presphenoid or basisphenoid bone.[2] Their development and form are variable between and within species, and features of the sphenopalatine vacuities have been used as characters in cladistic analyses.[3]

Among Oryzomyini, a mainly South American group, a 2006 study distinguished three character states—large, wide vacuities, as among others in Oligoryzomys and Holochilus; small, narrow vacuities, as among others in Lundomys and Nephelomys; and no or vestigial vacuities, as among others in Mindomys and Oryzomys.[2] Phyllotini all have very large sphenopalatine vacuities, as does Sigmodon. The vacuities in Reithrodon, formerly considered a phyllotine, are especially large.[4] Nyctomys is special in having sphenopalatine vacuities restricted to the basisphenoid bone.[2] Character polarity for the development of the vacuities in Cricetidae is difficult to determine, but their absence may be primitive in the Neotominae.[4]

The development of sphenopalatine vacuities has also been used to distinguish among members of the Sciurini group of squirrels.[5]


  1. ^ Weksler, 2006, p. 37, fig. 20
  2. ^ a b c Weksler, 2006, p. 37
  3. ^ Weksler, 2006, p. 37; Steppan, 1995, pp. 37–38; Carleton, 1980, p. 44
  4. ^ a b Steppan, 1995, p. 38
  5. ^ Moore, 1959, p. 179

Literature citedEdit