Paleoecology of the Niland Tongue

The swamp or paludal ecosystem is preserved in coals and carbonaceous shales. Remains of organisms of the swamp communities consist of bacteria and fungi; algae; invertebrates such as pelecypods, gastropods, ostracodes, and insects; vertebrates such as a hard-shelled turtle and crocodiles; and vascular plant remains. Aquatic communities are found in dark shale and are represented by the remains of bacteria and fungi; algae; invertebrates such as pelecypods, gastropods, and insects; and vertebrates such as crocodiles, fish, and a soft-shelled turtle. No vascular macrophytes (rooted aquatic vegetation) could be identified in the pollen and spore assemblage. Charophytes are abundant and show that colonies of the aquatic alga lived on the lake bottoms. The great variety of organisms suggests that the environment had a high input of nutrients. The phosphate-rich Phosphoria Formation, which could serve as a good source of nutrients, cropped out in the watershed of the Niland Tongue basin. The ostracode-crocodile association, calcareous charophytes, and good preservation of plant tissues and palynomorphs put limits on the alkaline geochemical environment in which the lacustrine rocks were deposited. The palynomorphs in the Niland Tongue rocks are dark yellow and light brown in color. These colors suggest that rocks containing them have beenmore » buried deeper in the past than they are today.« less