Table 4. Comparative table summarizing the main differences between the facial nerve systems.
| Taxon | Specimen number | Clade | Geniculate ganglion position | Hyomandibular nerve path | Vidian nerve path | Bones forming the canalis nervus vidianus |
|---|---|---|---|---|---|---|
| Chelodina oblonga | NHMUK 64.12.22 | Chelidae | cci | cnhp + sulcus | cci + cnv | pro + pt + bs |
| Chelus fimbriatus | NHMUK 81.9.27.4 | Chelidae | cci | cnhp + sulcus | cnv | pro + pt + par |
| Emydura subglobosa | PIMUZ lab 2009.37 | Chelidae | cci | cnhp | cci + cnv | pro + pt |
| Hydromedusa tectifera | SMF 70500 | Chelidae | cci | cnhp + sulcus | cci + cnv | pro + pt + bs |
| Phrynops geoffroanus | SMF 45470 | Chelidae | cci | cnhp + sulcus | cci + cnv | pro + pt |
| Phrynops hilarii | NHMUK 91.3.16.1 | Chelidae | cci | cnhp + sulcus | cci + cnv | pro + pt |
| Podocnemis unifilis | FMNH 45657 | Podocnemididae | pro | cnhp + sulcus + cnhd | scv + cnv | pt + pal + par |
| Podocnemis unifilis | NHMUK 60.4.16.9 | Podocnemididae | pro | cnhp + sulcus + cnhd | cnv | pt + pal + par |
| Pelomedusa subrufa | NMB 16229 | Pelomedusidae | cci | cnhp + sulcus | cci + cnv | pt |
| Pelusios subniger | NMB 16230 | Pelomedusidae | cci | cnhp + sulcus | cnv | pro + pt + bs |
| Carettochelys insculpta | NHMUK 1903.7.10.1 | Carettochelyidae | pro | cnhp + sulcus | cci + cnv | pt + pal |
| Carettochelys insculpta | SMF 56626 | Carettochelyidae | pro | cnhp + sulcus | cci + cnv | pt + pal |
| Amyda cartilaginea | FMNH 244117 | Trionychidae | ccv | conf | cci + ccl + scv + cnv | pt + pal |
| Apalone mutica | PCHP 2746 | Trionychidae | ccv | sulcus | cci + ccl + scv + cnv | pt + pal |
| Apalone spinifera emoryi | FMNH 22178 | Trionychidae | ccv | sulcus | cci + ccl + scv + cnv | pal |
| Chitra indica | NHMUK 1926.12.16.1 | Trionychidae | pro | cnhp | cci + ccl + scv + cnv | pal |
| Cyclanorbis senegalensis | NHMUK 65.5.9.21 | Trionychidae | pro | cnhp | cci + ccl + scv + cnv | pal |
| Cycloderma frenatum | NHMUK 84.2.4.1 | Trionychidae | pro | cnhp | cci + scv + cnv | pt + pal + par |
| Lissemys punctata | SMF 74141 | Trionychidae | pro | cnhp | cci + ccl + scv + cnv | pt + pal |
| Pelodiscus sinensis | IW576-2b | Trionychidae | ccv | sulcus | cci + ccl + scv + cnv | pal |
| Kinosternon baurii | FMNH 211705 | Kinosternoidea | ccv | sulcus | cci + ccl + scv + cnv | pt + pal + par |
| Kinosternon scorpioides | SMF 71893 | Kinosternoidea | ccv | sulcus | cci + ccl + scv + cnv | pt + epi + pal |
| Kinosternon subrubrum hippocrepis | FMNH 211711 | Kinosternoidea | ccv | sulcus | cci + ccl + scv + cnv | pt + pal |
| Staurotypus salvinii | NHMUK 1879.1.7.5 | Kinosternoidea | ccv | conf | cci + cnv | pt + pal |
| Sternotherus minor | FMNH 211696 | Kinosternoidea | ccv | sulcus | cci + ccl + scv + cnv | pt + pal |
| Dermatemys mawii | SMF 59463 | Kinosternoidea | ccv | conf | cci + ccl + scv + cnv | pal |
| Chelydra serpentina | SMF 32846 | Chelydridae | ccv | sulcus | cci + cnv | pt |
| Macrochelys temminckii | FMNH 22111 | Chelydridae | ccv | conf | cci + cnv | pt |
| Caretta caretta | NHMUK 1938.1.9.1 | Cheloniidae | ccv | conf | cci + scv | NA |
| Caretta caretta | NHMUK 1940.3.15.1 | Cheloniidae | ccv | conf | cci + scv | NA |
| Chelonia mydas | NHMUK 1969.776 | Cheloniidae | ccv | sulcus | cci + scv | NA |
| Eretmochelys imbricata | FMNH 22242 | Cheloniidae | ccv | conf | cci + scv | NA |
| Lepidochelys olivacea | SMNS 11070 | Cheloniidae | ccv | sulcus | cci + scv | NA |
| Natator depressus | R112123 | Cheloniidae | ccv | conf | cci + scv | NA |
| Dermochelys coriacea | FMNH 171756 | Dermochelyidae | cci | cnhp + conf | cci + scv | NA |
| Dermochelys coriacea | UMZC R3031 | Dermochelyidae | cci | cnhp + conf | cci + scv | NA |
| Platysternon megacephalum | SMF 69684 | Emysternia | ccv | conf | cci + cnv | pt + pal |
| Clemmys guttata | FMNH 22114 | Emysternia | ccv | sulcus | cci + ccl + scv + cnv | pt + epi |
| Deirochelys reticularia | FMNH 98754 | Emysternia | ccv | sulcus | cci + ccl + cnv | pro + pt + bs + epi + par |
| Emydoidea blandingii | FMNH 22144 | Emysternia | ccv | sulcus | cci + ccl + scv + cnv | pt + epi + par |
| Emys orbicularis | SMF 1987 | Emysternia | ccv | sulcus | cci + ccl + scv + cnv | pt + epi + par |
| Glyptemys insculpta | FMNH 22240 | Emysternia | ccv | conf | cci + scc + ccl + cnv | pt |
| Glyptemys muhlenbergii | UF 85274 | Emysternia | ccv | conf | ccl + scv + cnv | pt |
| Graptemys geographica | NHMUK 55.12.6.11 | Emysternia | ccv | sulcus | cci + ccl + cnv | pt + pal |
| Pseudemys floridana | FMNH 8222 | Emysternia | ccv | conf | cci + ccl + cnv | pt + pal |
| Terrapene coahuila | FMNH 47372 | Emysternia | ccv | sulcus | cci + ccl + cnv | pt + epi |
| Terrapene ornata | FMNH 23014 | Emysternia | ccv | sulcus | cci + ccl + cnv | pt + epi |
| Agrionemys horsfieldii | PCHP 2929 | Testudinidae | ccv | sulcus | cci + cnv | pro + pt + pal |
| Aldabrachelys gigantea | NHMUK 77.11.12.2 | Testudinidae | pro | cnhd | cci + cnv | pt + epi + pal |
| Gopherus agassizii | FMNH 216746 | Testudinidae | ccv | sulcus | cci + cnv | pt + pal |
| Gopherus flavomarginatus | FMNH 98916 | Testudinidae | ccv | conf | cci + cnv | pt + epi + pal + par |
| Gopherus polyphemus | FMNH 211815 | Testudinidae | ccv | cnhd | cci + cnv | pro + pt + pal |
| Indotestudo elongata | SMF 71585 | Testudinidae | pro | cnhp + conf | cci + cnv | pt + pal |
| Indotestudo forstenii | SMF 73257 | Testudinidae | pro | sulcus | cci + cnv | pt |
| Kinixys erosa | SMF 40166 | Testudinidae | ccv | sulcus | cnv | pro + pt + pal + par |
| Malacochersus tornieri | SMF 58702 | Testudinidae | ccv | sulcus | cci + cnv | pro + pt + pal |
| Psammobates tentorius verroxii | SMF 57142 | Testudinidae | pro/cci | sulcus | cci + cnv | pt + pal |
| Testudo marginata | FMNH 51672 | Testudinidae | ccv | sulcus | cnv | pro + pt + epi + pal + par |
| Batagur baska | NHMUK 67.9.28.7 | Geoemydidae | ccv | sulcus | cci + ccl + scv + cnv | pt + pal |
| Cuora amboinensis | NHMUK 69.42.145 | Geoemydidae | ccv | sulcus | cci + ccl + scv + cnv | pt + pal + par |
| Cyclemys dentata | NHMUK 97.11.22.3 | Geoemydidae | ccv | sulcus | cnv | pro + pt + par |
| Geoclemys hamiltonii | NHMUK 87.9.30.1 | Geoemydidae | ccv | sulcus | cci + ccl + scv + cnv | pt + pal + par |
| Geoemyda spengleri | FMNH 260381 | Geoemydidae | ccv | sulcus | ccl + cnv | pro + pt |
| Malayemys subtrijuga | NHMUK 1920.1.20.2545 | Geoemydidae | ccv | sulcus | cci + cnv | pt + pal + par |
| Mauremys leprosa | NHMUK unnumbered | Geoemydidae | pro | sulcus | cci + scc + ccl + scv + cnv | pt + epi + par |
| Morenia ocellata | NHMUK 87.3.11.7 | Geoemydidae | ccv | conf | cci + scc + ccl + scv + cnv | pt + pal + par |
| Pangshura tecta | NHMUK 1889.2.6.1 | Geoemydidae | ccv | sulcus | cci + cnv | pt + pal |
| Rhinoclemmys melanosterna | FMNH 44446 | Geoemydidae | cci | sulcus | cci + cnv | pt + epi + pal + par |
| Siebenrockiella crassicollis | NHMUK 1864.9.2.47 | Geoemydidae | ccv | sulcus | cci + ccl + scv + cnv | pt + pal + par |
Note:
Abbreviations: bs, basisphenoid; cci, canalis caroticus internus; ccl, canalis caroticus lateralis; ccv, canalis cavernosus; cnhd, canalis nervus hyomandibularis distalis; cnhp, canalis nervus hyomandibularis proximalis; cnv, canalis nervus vidianus; conf, hyomandibular nerve confluent with the canalis cavernosus; epi, epipterygoid; pal, palatine; par, parietal; pro, prootic; pt, pterygoid; scc, short-cut canal; scv, sulcus cavernosus; sulcus, hyomandibular nerve contained in a sulcus within the canalis cavernosus. Note that NA (non-applicable) is used when the canalis nervus vidianus is absent (chelonioids).