glossopteris

Glossopteris is a genus of extinct seed-bearing plants known from the Permian rocks of the ancient supercontinent Gondwana. It is most famous for its large, tongue-shaped leaves that occur in numerous species and have helped define the distinctive glossopterid flora of the late Paleozoic. Although common in the fossil record as leaf impressions, the genus is a form group used for a variety of related plants whose leaves resemble Glossopteris.

Morphology and classification: Glossopteris refers to leaves that are typically simple, oblong to obovate in shape, and endowed with a prominent midrib and reticulate venation. The plants were woody and likely ranged from shrubs to small trees, though most fossil evidence consists of leaves and occasionally associated reproductive structures. Glossopterids are placed in a broader group of extinct seed plants often called seed ferns (pteridosperms), within the order Glossopteridales. The reproductive organs are infrequently preserved, so leaf morphology is the primary basis for identification.

Distribution and significance: Fossils of Glossopteris have been found across Africa, South America, India, Australia, and Antarctica, indicating these landmasses formed part of a connected distribution in Gondwana. The widespread occurrence of Glossopteris leaves makes them a key biostratigraphic marker for Permian rocks in these regions and a cornerstone in reconstructing ancient geography. Their distribution provided influential evidence for plate tectonics and the existence of a southern supercontinent in the late Paleozoic.

Age and extinction: Glossopteris was most abundant in the Permian period and is generally considered to have declined by the end of the Permian, with the broader glossopterid flora disappearing around the Permian–Triassic boundary.