Trackways evidence of sauropod Dinosaurs Confronted by a Theropod found from middle Jurassic

Abstract

The temporal distribution of sauropod trackways generally parallels t fossils. The oldest sauropod trackways are found in Lower Jurassi s the record of sauropod body er Jurassic deposits of Africa, North America, and Asia: trackways are abundant throughout the rest of the Jurassic and Lower Cretaceous, but fewer are recorded in the Upper Cretaceous rocks. The foot structures usually fairly conservative within those of the various dinosaur groups are groups. Trackways are particularly promising records of dinosaur locomotion because they represent the trace of an act-a moment in time and therefore can provide information that is usually unavailable from skeletal morphology alone. Remains of a diversified paleobiota are found in the middle Indus basin, which includes plants (gymnosperm), mollusks, reptiles (cranial and post cranial bones). The commonest vertebrate fossils belong to sauropod and theropod dinosaurs, and mesoeucrocodilian fauna that occur a wide geographic area. Recently the author have found footprints of sauropod confronted with a theropod, in the middle Jurassic Samana Suk Limestone of Surghar Range, Mianwali district, Punjab Province, Pakistan. Five species of Late Cretaceous and one species of Late Jurassic titanosaurian sauropod, and one species of Late Cretaceous Abelisauran theropod dinosaur from Pakistan have already been established. But one new genus and species Malasaurus mianwali of middle Jurassic sauropod and one new genus and species Samanadrinda surghari of large bodied theropod based on only ichnofossils, are tentatively erected. Large pes foot print having length/width about 1 metre are diagnosed only only for a large bodied. sauropod. The manus footprints are totally overlapped by the pes prints. These tracks suggest the gregarious behavior of narrow gauge locomotors defending the attack of predatory theropod. This is the reason these are not referred to previously erected species of titanosaurs from Pakistan, because they may belongs to wide gauge trackways. These footprints are surely assigned to sauropod, but its assignment to lower level is difficult. Three slender toed foot prints having maximum length about 2 feet and width about 1.5 feet are diagnosed only for a large bodied theropod. These footprints are surely assigned to Theropod, but its assignment to lower level is difficult. Both the sauropod and theropod genera erected are named only to refer for future research work regarding locomotion, behavior, soft and hard tissues. This ichnotype reveal the scenario of confrontation among a carnivorous Samanadrinda surghari theropod and the groups of herbivorous Malasaurus Mianwali sauropods. This ichnocoenosis consists of exposed about 15 footprints, and 4 short trackways. Three trackways are interpreted as mainly produced by sauropods which are obliquely confronted by a track of large Theropod. They are indicative of a sauropod herd, composed of 3 or more individuals and furnish evidence of gregariousness (herd). The ichnofossils are usually deep footprints probably due to good granolometric sorting and the high plasticity of the limy substrate. In the vicinity, some foot prints of possibly birds/ small body theropod/coelorusaurs are also present. The ichnofossils of sauropod dinosaurs confronting a theropod of upper Indus Basin are a unique record of a middle Jurassic dinosaurian fauna which inhabited the north western margin of Indo-Pakistan subcontinental plate.