TAPHONOMY OF SOME VERTEBRATE FOSSILS FROM HEMRIN ANTICLINE, MIDDLE IRAQ

Abstract

The study area is located near Injana area; about 140 Km north of Baghdad City, middle Iraq. The Late Miocene – Pliocene site of the Mukdadiya Formation which is exposed in the northeastern limb of Hemrin South Anticline is a good example for the vertebrate fossil bones. The fossil bones can be studied by multidisciplinary sciences; tectonics, sedimentology, vertebrate fossils taxonomy and volcanic activities to understand the taphonomic processes of the involved fossil assemblages. The Alpine Orogeny in the Late Miocene increased the uplifting, folding and shortening of the Zagros Thrust Fold Belt and subsidence of the Zagros Foreland Basin in middle Iraq. Large fluvial systems, especially alluvial fans have been flowing from the northeast to the southwest in relatively humid climates. The current study concluded the following: The appearance of 21 species in the site refers to the humid and more luxurious environment. Availability of water and sediments (sand, mud, and clay) near fluvial sub environments enriched the diversity of plant that helped a different kind of amphibians such as crocodiles and turtles to living and breeding. The plant diversity provided the food for herbivores such as deer, giraffes, horses, mastodons, and later for the predators and carnivores. The presence of tuff stone, glass shards, pyroclastic crystals, tuffaceous sandstone, tuffaceous mudstone and tuffaceous claystone refer to volcanic activities and caused the suffocation and mass mortality of animals during the Late Miocene – Pliocene. Soft parts of dead animals were decay, while the bones transported by fluvial channel during heavy rain and mixed with the channel bed loads. They might be deposited and reworked by many cycles of deposition and finally, the redeposit within channel lag deposits in the lower part of point bars of the fluvial environment.