Extinct Horned Crocodile Figure 8. Phylogenetic relationships recovered by a maximum parsimony analysis of 98 morphological characters. Adams consensus of 426 equally optimal trees (length = 225, CI excluding uninformative characters = 0.493, RI = 0.717). Dashed lines indicate lost resolution in a strict consensus of the same trees. O = Osteolaeminae, M = Mekosuchinae, T = Tomistominae. Heavy branches indicate living lineages. doi:10.1371/journal.pone.0009333.g008 discrete knobs on the prefrontal are either absent or weakly developed, and there is usually a discontinuity between the upturned orbital margin and any dorsal reflection of the lateral skull table margin. An anteroposterior crest is usually found on the dorsal surface of the lacrimal in crocodylids, though it is especially well-developed in most Indo-Pacific species of Crocodylus and some extinct osteolaemines. But in these, the crest takes the form of a long continuous ridge, not the discrete knobs seen in C. anthropophagus. These ornamental features are sufficient to distinguish C. anthropophagus from most other Neogene crocodylines. Crocodylus checchiai from the Miocene of Libya [7,11,50], Crocodylus gariepensis from the Miocene of Namibia [4], and Mio-Pliocene fossils referred to Crocodylus from Italy [46,51,52], the Manonga Valley of Tanzania [53](pers. obs.), and Abu Dhabi [54] uniformly lack squamosal horns and discrete prefrontal knobs. The squamosals of large crocodiles from the Late Miocene and Pliocene Lothagam and Koobi Fora localities referred in the past to Rimasuchus lloydi [2,17], however, are dorsally inflated. Although not to the degree seen in C. anthropophagus, this contrasts the Kenyan skulls with R. lloydi from the type locality [55] (pers. obs.), all of which have flat skull tables. Posterodorsal squamosal horns characterize the Cuban (Fig. 9B) and Siamese crocodiles [43,56]. Like C. anthropophagus, the horns of these species are sharply demarcated in both posterior and lateral view, at least in larger individuals. It is because of these structures that trees linking C. anthropophagus to C. rhombifer or C. siamensis are among the optimal arrangements. Nevertheless, C. anthropophagus PLoS ONE | www.plosone.org 9 February 2010 | Volume 5 | Issue 2 | e9333