Existence of a single island was determined in 1903 by the Scottish National Antarctic Expedition under William Speirs Bruce, who so named it because what were thought to be graptolite fossils were found there.
[1][2] Later analysis showed that the fossils on Graptolite Island were merely the remains of ancient plants.
[3][4] The bedrock of Graptolite Island consists entirely of a geologic unit known formally as the Greywacke Shale Formation.
These beds were deposited by turbidity currents as turbidites in submarine fans and later metamorphosed to between anchizone to upper greenschist-facies during the late Triassic and early Jurassic.
[6] The island, along with the nearby Ferrier Peninsula, has been identified as an Important Bird Area (IBA) by BirdLife International because together they support a large breeding colony of about 91,000 pairs of Adélie penguins as well as 14,000 pairs of chinstrap penguins.