Attockicetus is described based on fragmentary cranial material. The holotype specimen, H-GSP 96232, includes a fragmentary rostrum, an endocast (interior of cranium), and an ectotympanic (ear bone). The specimen also had preserved cheek teeth, P3-M3, which is rare in remingtonocetids. Attockicetus is primitive in the retention of large protocones on the upper molars and the location of the orbits anteriorly on the skull. It is probably the most plesiomorphic remingtonocetid[2]
Additional dental material was found at the type locality and assigned to Attockicetus. Compared to pakicetid teeth found at the same locality, the P3 of Attockicetus is much lower, angled anteriorly, and has a very long posterior extension. A long diastema separates P3 from P4 and P3 is longer than P4, which was identified as a remingtonocetid character and, because Attockicetus is the only known remingtonocetid known from the Kala Chitta Hills, they tentatively assigned the specimen as belonging to this genus. The P4 of Attockicetus is similar to those of Pakicetus in retaining a tall protoconid (cusp) and anterior and posterior basal extensions with prominent cristae (crests), but differs from them in having steeper protoconid slopes, being taller, and having longer basal extensions. The molar wear in pakicetids is typically extensive, whilst the P4 in Attockicetus is less worn, suggesting that the latter was not used for breaking down food, but for holding prey.[1]
Cooper, Lisa Noelle; Thewissen, J. G. M.; Hussain, S. T. (2009). "New middle Eocene archaeocetes (Cetacea: Mammalia) from the Kuldana Formation of northern Pakistan". Journal of Vertebrate Paleontology. 29 (4): 1289–1299. doi:10.1671/039.029.0423. S2CID84127292.