Left (originally fig. 6.): Catopsbaatar catopsaloides, reconstruction of the skull, based on all available specimens, in dorsal view. The nasal vascular foramina are shown as preserved in PM 120/107. In other specimens there may be only two pairs of nasal vascular foramina.

Middle (originally fig. 8.): Catopsbaatar catopsaloides, reconstruction of the skull, based on all available specimens, in ventral view. The reconstruction is of an adult individual, but the upper premolars P1 and P3, which disappear during ontogeny, have been reconstructed. The teeth in maxilla are P1, P3, P4, M1, and M2. The choanal region and the middle part of the basicranial region (diagrammatical), including recognition of most of the foramina not preserved or poorly preserved in Catopsbaatar (see text for details), have been reconstructed on the basis of other djadochtatherioid genera, especially Kamptobaatar (Kielan−Jaworowska 1971), Nemegtbaatar (Kielan−Jaworowska et al. 1976), and Kryptobaatar (Wible and Rougier 2000).

Right (originally fig. 7.): Catopsbaatar catopsaloides, reconstruction of the skull, based on all available specimens, in lateral view. The reconstruction is of an adult individual, but the upper premolars P1 and P3, which disappear during ontogeny, are reconstructed. The bones of the orbit, not preserved in ZPAL and PM specimens and very fragmentarily preserved only in PIN 4537/4 and /5, have not been reconstructed. The dorsal part of the maxilla/squamosal suture is tentatively reconstructed on the basis of PIN 4537/5 (Fig. 3C, D) and a comparison with Djadochtatherium (Fig. 11B). The arrow points to the posterior zygomatic “ridge” (muscle scar), preserved on the squamosal above the glenoid fossa and discernible in occipital view. The teeth not marked on the dentary are p4 and m1, on maxilla P4 and M1. Date 2005 Source Kielan−Jaworowska, Z., Hurum, J.H., and Lopatin, A.V. 2005. Skull structure in Catopsbaatar and the zygomatic ridges in multituberculate mammals. Acta Palaeontologica Polonica 50 (3): 487–512. Author Bogusław Waks−mundzki, pubklished by Kielan−Jaworowska, Z., Hurum, J.H., and Lopatin, A.V.