. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 72 Bulletin Museum of Comparative Zoology, Vol. 156, No. 1. Figure 12. Prozostrodon brasiliensis, new genus. Right lower jaw of the holotype in nnedial view. Note the incipiently bifurcatec postcanine roots. lacking a posteriorly projecting angular process. A coronoid is probably present, largely fused to the medial side of the as- cending ramus. The unfused symphysis ex- hibits rugosity indicative of ligamentous insertion, and a symphysial fossa and fo- ramen as in Cynognathus (Kermack et al., 1973). The lower dentit
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 72 Bulletin Museum of Comparative Zoology, Vol. 156, No. 1. Figure 12. Prozostrodon brasiliensis, new genus. Right lower jaw of the holotype in nnedial view. Note the incipiently bifurcatec postcanine roots. lacking a posteriorly projecting angular process. A coronoid is probably present, largely fused to the medial side of the as- cending ramus. The unfused symphysis ex- hibits rugosity indicative of ligamentous insertion, and a symphysial fossa and fo- ramen as in Cynognathus (Kermack et al., 1973). The lower dentition consists of four in- cisors, one canine, and 10 postcanines (Barberena et al., 1987). The incisors are slightly procumbent and recurved, with some mesiodistal expansion of the crown in the first three. The fourth incisor is shorter, mesiodistally narrow, and separat- ed from the canine by a short diastema. The well-preserved postcanines become more complex toward the back (as is com- mon in carnivorous—insectivorous cyno- donts; Osborn and Crompton, 1973) as well as increase in size. The following ac- count is based on the right postcanines. Lower postcanine 1 is small, conical, and without accessory cusps. Lower postcanine 2 bears a large main cusp a with smaller cusps b (mesially) and c (distally). A slight lingual cingulum is present. On Pcg, cusp a has a sharp distal edge, and cusps b and c are positioned on the buccal half of the tooth. Incipient division of the root is ap- parent in buccal aspect. Lower postcanine 4, substantially larger than preceding post- canines and also exhibiting incipient root division, possesses a (broken) lingual cin- gulum and a mesial and distal lingual cus- pule. Lower postcanine 5 is mesiodistally longer than Pc^ and has larger accessory cusps b and c. The lingual cingulum is not continuous mesiodistally, but has anterior and posterior sections, each bearing a cus- pule. The base of the crown is larger than the root, which is well diffe
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