Option c is the correct answer.

• Statement a is correct: Primary succession always occurs on barren terrain. In Primary succession plants and animals first essentially colonize a barren and lifeless habitat. Species that arrive first in the newly created environment are called pioneer species.
• Statement b is correct: Primary succession occurs in regions where the substrate lacks soil. Examples of Primary succession include areas where lava recently flowed, a glacier retreated, or a sand dune formed.
• Statement c is incorrect: There is presence of both plant and animal species in primary succession. The pioneers through their death any decay leave patches of organic matter in which small animals can live.
• Statement d is correct: The rate of transformation of vegetation is very slow in primary succession. It is very rapid in secondary succession.

Primary succession refers to the colonization and establishment of plant communities in an area that is devoid of any soil or vegetation. Over time, through a series of ecological processes, the area transforms into a stable and diverse ecosystem. While primary succession occurs in a predictable pattern, there are certain misconceptions associated with it.

Incorrect Statement: No animal species are found in primary succession. (Option C)

Explanation:
The statement that no animal species are found in primary succession is incorrect. While it is true that primary succession begins in barren terrain, devoid of soil and vegetation, it does not mean that animals are absent during this process. In fact, various animal species can play important roles in primary succession by facilitating seed dispersal, soil formation, and nutrient cycling.

Key Points:
- Animal Species in Primary Succession: Animals such as birds, insects, and mammals can contribute to primary succession by dispersing seeds through their droppings or fur. This helps in the establishment of plant species in the area. Additionally, animals can also aid in the breakdown of organic matter and contribute to soil formation through their activities, such as burrowing and digging.

- Role of Animals in Nutrient Cycling: Animals also play a crucial role in nutrient cycling within the ecosystem. They consume plant matter and other animals, releasing nutrients through their waste. These nutrients can then be utilized by plants during their establishment and growth.

- Examples of Animal Involvement: In areas of primary succession, animal species like pioneer insects, rodents, and birds are commonly observed. For instance, in volcanic areas where primary succession occurs, insects like beetles and bees can be seen pollinating and aiding in the reproductive processes of early colonizing plant species. Similarly, small mammals like mice and voles can help disperse seeds as they move around the area.

- Gradual Transformation of Vegetation: While primary succession is a slow process, the rate of transformation of vegetation gradually increases over time. Initially, pioneer species such as lichens and mosses colonize the bare terrain, paving the way for grasses and herbaceous plants. Eventually, shrubs and trees establish themselves, leading to the development of a climax community.

In conclusion, the incorrect statement is option C, which claims that no animal species are found in primary succession. Animal involvement is crucial in primary succession, aiding in seed dispersal, soil formation, and nutrient cycling.