The snout was moderately long and the skull as a whole was deep, although crushing has reduced this depth and splayed out the cheeks, making the fossil wider than it would have been when alive. The overall shape and texture was similar to that of most other embolomeres, although there is no trace of lateral line canals. Sutures between skull bones are difficult to interpret with certainty, but when visible, their arrangement and structure is similar to that of other embolomeres (particularly English specimens commonly referred to Pteroplax or Eogyrinus). For example, the lacrimal bone is excluded from the front edge of the orbit (eye socket) due to a downward branch of the prefrontal bone, and the broad squamosal bone is only weakly attached to skull bones above it. The orbits were roughly circular, in contrast with a well-preserved embolomere skull from Newsham (initially referred to Anthracosaurus and now considered the lectotype of Eogyrinus), which has more triangular orbits due to the shape of the jugal bone, which forms the lower rim of the orbit. On the other hand, the jugal of Neopteroplax otherwise resembles that of the Newsham skull due to extending down far enough that it wraps under the rim of the mouth. The premaxilla (at the tip of the snout) had three teeth, with the first two rather large and the last one much smaller. The following maxilla bone had about 40 teeth, which were generally small except for a "canine" region of four or five larger teeth near the front part of the bone. All of the teeth were only preserved as broken stumps at best, so specific information about their shape is unobtainable. The front part of the palate (roof of the mouth) has large, elliptical choanae (internal nostrils) separated by narrow, toothless vomer bones. Most of the palate was formed by the plate-like pterygoid bones, which were covered with tiny denticles. The outer edge of each pterygoid connected to a small, rectangular palatine bone and the longer ectopterygoid, which lies immediately behind it. The palatine and ectopterygoid possessed very large fangs, with two on the palatine and six on the ectopterygoid. Very little of the braincase is well preserved, with the exception of the blade-like parasphenoid which extends forwards along the midline of the skull and divides most of the pterygoids from each other. The lower jaw of Neopteroplax possessed typical embolomere features such