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Stratigraphic chart of the lower Permian (partial) Content updated October 16, 2005
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RICHARDS SPUR UNIDENTIFIED SKULL Parareptilia? Below, pictures of an unidentified partial skull. Though the skull has a superficial Tersomius shape, the medially recurved teeth are not labyrhintodont.The large bone, here identified as parietal, in the center is preserved as a natural cast, but, the fossilized bone, fortunately, is present anteriorly, laterally and in the posterolateral corner. A raised border of matrix show the posterior margin of parietal and suggests that the two articulated parietals, posteriorly, would have formed a single median embayment. The parietal has, anteriorly, two distinct areas for the articulation with postfrontal and frontal, and laterally a semilunate area for articulation with supratemporal, but seems to lack the area for articulation with a large postparietal. The prefrontal has a quite large medial flange, so the anterior orbital rim is much broader than the posterior one, The orbit is expanded posteriorly and the size of the postfrontal is greatly reduced in relation to the prefrontal. The frontal is elongate and has a posterolateral flange interposed between postfrontal and parietal. The general shape of the maxilla fragment and of the teeth is similar to PR 1089, as illustrated by Bolt (1980). As the lingual side is still in the matrix it would need a careful preparation to see if the teeth are fluted or weakly bicuspid, if it would be confirmed, could be a support of the suggestion of Bulanov (2002) about the possible presence of Nyctiphruretid related parareptiles at Fort Sill. From Richards Spur (Fort Sill, Dolese Quarry), Comanche Co. - Oklahoma. Lower Permian. 1) Richard Spur Unidentified Skull: lateral 2) Richards Spur Unidentified Skull: dorsal 2) Richards Spur Unidentified Skull: posterior view (enlarged) 3) Richards Spur Unidentified Skull: anterior view (enlarged) 4) Richards Spur Unidentified Skull: teeth
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