The head appears to have been partially de-fleshed prior to encapsulation in the amber matrix (Figure 1). Skin is visible on the left side of the skull. Description of the scale pattern, as observed under a dissecting microscope, follows Williams et al. (1995). Taphonomic damage due to soft tissue decomposition adds uncertainty to some of the scale counts. The rostral is broad. There are seven supralabials to below the center of the eye. Three preoculars and three suboculars are preserved, although it is unclear whether the preserved series is an accurate reflection of the total number in life. The suboculars are in contact with the supralabials. Four canthals are clearly discernable. A minimum of 35 loreals are preserved with five loreal rows present. Ventrally, there are two sublabial and three postmental scales (including sublabials) on each side of the midline, for a total of six postmentals. The gular region, preserved as a semi-transparent membrane, lacks gular folds.

The skull is 7.44 mm in length and 3.74 mm wide as measured across the jugals, similar in size and proportion to the two other amber- preserved specimens (10.5 x 4.5 for AMNH DR-SH-1, ~8.5 x 4.5 for the NMBA specimen; de Queiroz et al. 1998). It is relatively complete, with damage restricted primarily to the right lateral and posterodorsal regions.

The skull has a T-shaped, unpaired premaxilla with a narrow internarial bar that extends posteriorly to about the third or fourth maxillary tooth position (Figure 2, Figure 3, Figure 4). Lateral premaxillary processes form the anterior floor of the external nares. Two sub-conical premaxillary teeth are preserved, one each in the lateral position of each side, with room for a total of five or six tooth positions. Articulation with the maxilla is oblique and loose. Septomaxillae and nasals are not preserved.

The maxillae are damaged along their dorsomedial margins. Maxillary palatine processes are well developed, protruding medially at about the seventh maxillary tooth position. The maxillae are depressed in lateral view to form the posterior floor of the external nares. Thirteen or 14 tooth positions are preserved in each maxilla, the tooth row extending posteriorly beyond the ectopterygoid contact. The left prefrontal is nearly complete, the right is badly damaged. The maxillary-prefrontal sutures are indistinct, but the junction presents a continuous surface. The prefrontals probably did not contact the nasal, as the apparently complete anterolateral process of the frontal appears to exclude this contact.

The anterior roof table is formed by the frontal, which is relatively complete. Diverging anterior processes extend anterolaterally to contact the prefrontals and medially exhibit a shelf-like facet for articulation with the nasals. There is no evidence of an anterior medial process as seen in A. carolinensis (Stimie 1966), but instead the frontal forms a v-shaped cleft. The frontal is strongly constricted between the orbits, forming their complete dorsal margin. Discernable parietal remnants occur only at the lateral frontal-parietal suture; however, an inverted cone-like notch is preserved at the midline of the suture (Fig. 3.1, Fig. 4.2) and may represent the anterior wall of the pineal foramen. Postfrontals are not present as in the NMBA specimen. Although a left postfrontal is reported on the AMNH specimen, examination of the stereo-radiograph in de Queiroz et al. (1998) illustrates the element in a damaged portion of the skull and suggests it may as likely represent a fragment of the frontal.

The left lacrimal is present, forming the anteroventral margin of the orbit, and meeting the anterior margin of the jugal posteroventrally. The anterior terminus of the jugal is lateral to the posterior maxillary tooth position. The jugal forms the greater portion of the ventral and posterior orbital margin, and overlies the lateral face of the postorbital posteriorly. There is no contact of the jugal with the squamosal. The tri-radiate postorbitals are complete; the two anterior processes complete the posterodorsal orbital margin, while the third extends posteriorly to contact the squamosal, although this junction is not clearly defined. The rod-like squamosal lies lateral to the preserved left supratemporal and does not appear to have had contact with the parietal. It terminates posteriorly in a hook-like, ventrally directed process that extends into the tympanic recess of the quadrate.

Only the left quadrate is preserved. It is anteroventrally oriented and the main shaft is long and narrow (4:1 length/width). The tympanic rim is well developed, extending from the squamosal to the posterolateral shelf that lies dorsal to the articular facet of the mandibular fossa, forming a shallow concavity.

Of the palatal bones, the left and right ectopterygoids and left pterygoid are present. The left ectopteryogoid-pterygoid contact is unclear. The ectopterygoid contacts the jugal near the posterior terminus of the maxilla. Pterygoid teeth are not present, and there is no contact of the pterygoid (or ectopterygoid) with the lacrimal.

There is significant damage to the braincase and little of this region could be resolved. Of the basicranial elements, the parabasisphenoid is absent and the basioccipital is fragmentary. The left prootic and opisthotic are present, exposing the osseous labyrinth medially. Within the osseous labyrinth, the posterior semi-circular canals, which do not exhibit prominent ridges on their surfaces, are visible. Nothing could be discerned concerning fusion or suturing of contacts. Within the fenestra ovalis there is the remnant of a ring-like ossifcation that may be the stapedial footplate.

The mandibles are relatively well preserved (Figure 5). The dentaries each bear 17-18 tooth positions. The anterior teeth are sub-conical, with tricuspid tooth morphology appearing at about the tenth tooth position. There is no sculpting of the dentaries. However, the left dentary displays a laterally and medially directed ossified protuberance that may represent a pathology. As many as six mental foramina are present on the lateral surface of each dentary. Meckel's groove is enclosed to the posterior tooth position. The posteromedial end of the dentary is divided into dorsal and ventral processes; the dorsal process terminates against the anterior process of the coronoid while the ventral process tapers posteriorly, terminating ventral to the apex of the coronoid. Laterally, the dentary meets the surangular in a poorly defined suture.

The ventral extension of the labial process of the coronoid is unclear. The anteromedial process extends ventrally to terminate without a posterior projection, and the posteromedial process contacts the articular. There is no splenial. It is unclear if the angular is present. The surangular forms the dorsal margin of the lower jaw posterior to the coronoid process. There is a well-developed medial angular process of the articular.