Abstract :
Continental vertebrates are restricted in their geographic distribution by marine and oceanic barriers, which affect all forms, except the birds. Occasionally these barriers break totally or partially and the faunas disperse outside the area of original distribution in diverse forms. These bridges, "land bridges" or "corridors", allow the free circulation of faunas in both directions. Isolation between the northern and southern continents produced dramatically different distribution among dinosaurs. In contrast to northern hemisphere, the dominant herbivores in the Late Cretaceous of India and South America were titanosaurids rather than ornithischians, whereas the large predators were abelisaurids instead of tyrannosaurs. Examination of fossil records indicates that at the end of the Early Cretaceous, the best adapted and potentially adapted family of sauropod was the Titanosauridae. They flourished in the Late Cretaceous and survived after all the other sauropods had become extinct. After the break up of Gondwanaland, the isolation of the titanosaurids in Indo-Pakistan during much of the Late Cretaceous, without competition from other herbivorous dinosaurs, resulted in a diversification into two families with a total of 5 genera. Thus far, the Late Cretaceous (Maastrichtian) Lameta Formation of India had served as the sole source of information on Cretaceous vertebrates of the Indo-Pakistan subcontinent. But now discoveries by the author include a variety of large vertebrate that indicate the first Late Jurassic Titanosaurs(one species), first Late Cretaceous herbivorous Titanosaurs (five species) and carnivorous Abelisaurs(one species) Dinosaurs and Pabwehshi a Baurusuchids (Mesoeucrocoreptilia) fossils, have broadened their distribution. These discoveries of Jurassic and Cretaceous Arhosaurian reptiles from Pakistan provide a vantage point and act as a milestone for assessing paleobiogeography and phylogeny. The discovery of Saltasaurids, Abelisaurids, and Baurusuchids from Pakistan broadens their distribution and may prove the close affinity with India, Madagascar and South America. Pakistani Titanosauria shows some affinity with the Late Cretaceous fauna of Europe, and North America. But its resemblance of some skull and especially teeth characters with Mongolian-Chinese forms like Nemegtosaurus and Quaesitosaurus are encouraging to say the titanosauria as a Global/Pangean distribution. The findings of Vitakridrinda- an Abelisaurids from Pakistan broaden their spatial distribution and matches with the Gondwanan linkage theory.
