Although the skull in general possesses a combination of amniote and non-amniote features, the palate noticeably lacks amniote adaptations. Most of these missing adaptations relate to the pterygoid bones, which are elongated blade-like structures that lie along the middle of the palate. The palate lacks "labyrinthodont" features such as large fangs, and instead the pterygoids are completely covered with small tooth-like prickles known as denticles. This is unusually primitive compared to early amniotes, which typically have denticles concentrated in only a few parts of the pterygoids. Several rows of denticles are also present along the palatine bones along the rim of the mouth, but apparently not the ectopterygoid bones immediately behind the palatines. The rear of the palate possesses a bone known as a parasphenoid, which has acquired an unusually complex dart-like shape. The pterygoids each have a thin rear branch that reaches as far back as the jaw joints, while further towards the front of the skull they converge together. Perhaps the most notable feature of the palate is the fact that the rear branches of the pterygoids are simple, with concave outer edges. This is in notable contrast to all early amniotes, in which this area possesses an outward prong (known as a 'transverse flange') which is covered with teeth. Further preparation of the skull to reveal this feature of the palate is one of the primary reasons why "Westlothiana's" classification was reworked to belong outside Amniota.