Final answer:
The information provided does not specifically identify a hominin with a nearly pure C4 signal, but Paranthropus boisei is known for a strong C4 dietary signal in paleoanthropological studies.
Step-by-step explanation:
The hominin species with a nearly pure C4 dietary signal has not been directly mentioned in the provided information. However, dietary signals related to C3 and C4 plants are typically discussed in the context of hominin species, where isotopic analysis of dental enamel is used to infer the types of plants that were part of a hominin's diet. The C4 signal indicates the consumption of grasses and sedges or animals that fed on C4 plants. It's noteworthy that among the Paranthropus genus, specifically Paranthropus boisei, a strong C4 dietary signal has been detected, suggesting a significant involvement of C4 plants in their diet. Nonetheless, provided information does not clearly identify a hominin with a nearly pure C4 signal. It is important to reference more specific paleoanthropological evidence to accurately identify which hominin species exhibit nearly pure C4 dietary signals.