Which fossil was notably found as evidence supporting continental drift?

The fossil of the seed fern Glossopteris is a significant piece of evidence supporting the theory of continental drift because it was discovered across several continents that are now widely separated, including South America, Africa, Antarctica, India, and Australia. This widespread occurrence of the same plant species on different continents suggests that these landmasses were once connected, allowing for the distribution of Glossopteris.

The presence of this seed fern in such disparate locations aligns well with the idea of continents drifting apart over geological time, as it would be improbable for the seeds to have traveled vast ocean distances to reach isolated landmasses after they had separated. Additionally, Glossopteris is a distinctive fossil that would have had limited means of dispersal, further supporting the notion that the continents were once joined and that the species had a larger contiguous habitat before they split apart.

In contrast, the other options represent organisms that either existed in different geological periods or were not as widely distributed as Glossopteris. Thus, the fossil record of Glossopteris provides compelling support for the concept of continental drift.