. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 420 Bulletin Museum of Coniparativc Zoology, Vol. 135, No. 8. Fig. 3. Occipital view of Proterochampsa barnonuevoi, MCZ 3408. X Vl- that of later crocodiles. It miicli larger than the modern crocodilian ([iiadratojugal and forms the posterolateral corner of the dorsal surface of the skull. Anteriorly, it joins with the jugal, forms the posterolateral margin of the infratemporal fossa, and unites medially with the squamosal. Pos- teriorly and medially, the quadratojugal has a smooth face which joins with the c^uad-
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 420 Bulletin Museum of Coniparativc Zoology, Vol. 135, No. 8. Fig. 3. Occipital view of Proterochampsa barnonuevoi, MCZ 3408. X Vl- that of later crocodiles. It miicli larger than the modern crocodilian ([iiadratojugal and forms the posterolateral corner of the dorsal surface of the skull. Anteriorly, it joins with the jugal, forms the posterolateral margin of the infratemporal fossa, and unites medially with the squamosal. Pos- teriorly and medially, the quadratojugal has a smooth face which joins with the c^uad- rate. On the palatal surface, the suture of the quadratojugal and the jugal runs diagonally forward. Its other ventral contact is with the quadrate, on which it sits like a cap with the lateral edge folded under. The dorsal and lateral parts of the bone are sculptured to about the same extent as the jugal, being more massive along the infra- temporal bar. The posterior face of the bone is smooth and quite steeply inclined down to its jimction with the quadrate. Quadrate. In its posterior aspect the quadrate of Frotcrochampsa resembles that of advanced crocodilians in extending up- ward and medially with a smooth sloping face to join the exoccipital and the squamo- sal; it is not, howeven-, overlain by the lat- ter as in eusuchians. Further, it is quite unlike Recent crocodiles in having the ex- ternal auditor)' meatus in the form of a groove going into the inner ear along the posterodorsal part of the quadrate, anterior to the exoccipital and underneath, but not enclosed by, the scjuamosal (see discussion of ear region below). The configuration of the articulating condyles of the quadrate is similar to that of some of the mesosuchian crocodiles [Teleosauridae, Libycosuchidae, and Metriorhynchidae (Kiilin, 1955)] in the presence of two condyles, the medial larger than the lateral. This is in contrast, on the one hand, to the usual thecodont condition of only one condyle and, on
Size: 3246px × 770px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorharvarduniversity, bookcentury1900, booksubjectzoology
