Answer:
Infer Desmatosuchus would be more useful as a fossil clue to the Triassic Period.
Step-by-step 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.