Question

Infer Desmatosuchus was a crocodile relative that lived only during the Triassic Period. Horsetails are plants that first appeared in the Triassic Period and still exist. Which of these organisms would be more useful as an index fossil for the Triassic Period? Why?

Answer 1

The more useful specimen will be the Horsetail. The plants give better picture for the place where they were found than the skeletons of the animals. The plants are excellent indicators of how was the climate at a certain place (sunlight, precipitation, soil, temperature), and also they give a very clear picture about the environment in which they lived. So plant fossils are much more useful when recreating the full picture, the animal reconstructions are influenced by the indicators that the plants give us, not vice versa. 

Answer 2

Answer:

Infer Desmatosuchus would be more useful as a fossil clue to the Triassic Period.

Explanation:

Creatures of soft consistency are less likely to turn into fossils. A plant such as Horsetails is a creature of soft consistency that can be easily decomposed or crushed into sediment without leaving traces.  On the other hand, an Infer Desmatosuchus takes longer to decompose, in addition to the bones, teeth and nails of such animals will be easier to become fossils than a plant, so this animal is the most useful organisms as a fossil index for the Triassic Period.