In on the sheer number of leaf

In this lesson, learn about the glossopteris, an extinct genus of seed-bearing plant that was common 250 million years ago. Read about the qualities and time period of this plant, and then test your knowledge with a quiz.

The Glossopteridales

Glossopteris was the most common genus of an extinct family of seed-bearing, or flowerless, plants collectively called Glossopteridales. The genus name means ‘tongue fern,’ a reference to the shape and general appearance of its leaves.

Our Authors Write a Custom Essay
For Only $13.90/page!


order now
Fossilized Glosopteris
Glossopteris

Although dozens of species of Glossopteris have been identified from leaf fossils, the true number of species remains uncertain. That’s because, except for a few root fossils, no other parts of the plants – twigs, branches and so on – are found.

So, we can’t be certain whether all of the different leaf types represent distinct species. They could be leaves from different growth stages or parts of the same plant.We don’t know for sure exactly what the plants looked like, either. The best guess is that it looked like some type of bush or shrub. Most paleo-botanists think the plants were deciduous, or dropped its leaves in autumn. That is an inference, based on the sheer number of leaf fossils found and the fact that the plants grew in a temperate climate at middle to high latitudes (where deciduous plants grow today).

Another mystery lies in how Glossopteris species are related to modern plants. Early researchers classified them as ferns. Later on, they were placed into the same group of plants as gymnosperms (the seed-bearers). But whether they actually have any close modern relatives is still up for debate.

Importance and Extinction of Glossopteris

During the Permian Period (about 299 to 251 million years ago), Glossopteris grew in thick stands all across the Southern half of the ancient supercontinent called Pangaea (the part known as Gondwana). They were so abundant for so long that accumulations of the dead plants eventually formed massive coal beds that are mined in Brazil, India, Australia and South Africa and also found in Antarctica.

The locations where Glossopteris fossils (and coal beds) are found today was one of the pieces of evidence used by Alfred Wegener in support of his hypothesis about continental drift. Wegener realized that identical species could not have evolved on separate continents, and the presence of the fossils and coal beds was best explained if all of the continents were next to one another during the time Glossopteris lived.

Pangea with Glossopteris distribution in dark green
Glossopteris distribution

Despite its prevalence, the genus did not survive long after the break-up of Pangaea (about 200 million years ago, during the Triassic Period). As the continents drifted apart, the climate changed in the areas where Glossopteris had thrived, and all of the species died out.

Lesson Summary

Glossopteris was the most common genus of an extinct family of seed-bearing, or flowerless, plants collectively called Glossopteridales. The genus name means ‘tongue fern,’ a reference to the shape and general appearance of its leaves. Most paleo-botanists think the plants were deciduous, or dropped their leaves in autumn. That is an inference, based on the sheer number of leaf fossils found and the fact that the plants grew in a temperate climate at middle to high latitudes.

During the Permian Period (about 299 to 251 million years ago), Glossopteris grew in thick stands all across the Southern half of the ancient supercontinent called Pangaea (the part known as Gondwana). The locations where Glossopteris fossils (and coal beds) are found today was one of the pieces of evidence used by Alfred Wegener in his support of his hypothesis about continental drift.

x

Hi!
I'm Sigvald

Do you need a custom essay? How about ordering an essay here?

Check it out