A. Evidence collected from western Argentina samples show that land plants, which played a critical role in changing the global climate and on the evolution of multicellular life, have established themselves in the dry parts of the globe about 8-12 million years earlier than previously thought. --- Incorrect. SV error. "Evidence" (singular), show (plural).
B. Evidence collected from western Argentina samples shows that land plants, which played a critical role in changing the global climate and in the evolution of multicellular life, had established themselves on the dry parts of the globe about 8-12 million years earlier than previously thought. -- Correct. Use of past perfect "had established" is correct. No pronoun issue. Plural usage.
C. Evidence collected from western Argentina samples shows that land plant, which played a critical role in changing the global climate and in the evolution of multicellular life, has established itself in the dry parts of the globe about 8-12 million years earlier than previously thought. -- "has established". We need past perfect form to indicate that the act of establishing plant life came before. Also when mentioning a general fact (indicated by lack of "the" before "land plant"), prefer plural usage.
D. Evidence collected from western Argentina samples shows that land plants,critically changing the global climate and in the evolution of multicultural life, has established itself in the dry parts of the globe about 8-12 million years earlier than previously thought. -- "has established", "itself" (SV error). Eliminate.
E. evidence collected from western Argentina samples show that land plants, which played a critical role in changing the global climate and in the evolution of multicultural life, has been established in the dry parts of the globe about 8-12 million years earlier than previously thought, --- "has been established" (dont need present perfect progressive).