It's a bit of a tricky question! While we can learn a lot from ancient seedless plants, we don't directly "use" them in the same way we use modern plants. Here's why:

* Fossil Fuels: The most significant way we use ancient seedless plants is through fossil fuels like coal and oil. These fuels formed over millions of years from the remains of ancient plants, including seedless varieties like ferns and lycopods. While these plants themselves are long gone, their fossilized remains power our industries and transportation.

* Scientific Research: Ancient seedless plant fossils provide invaluable information for scientists. They help us understand:

* Evolution: How plants evolved over millions of years.

* Climate Change: Past climates and how they've changed.

* Ecology: Ancient ecosystems and the relationships between organisms.

* Inspiration: Some modern technologies are inspired by the structures of ancient seedless plants. For example, the design of some aircraft wings is inspired by the intricate patterns found in fern fronds.

Important Note: It's crucial to remember that we are not using the actual ancient plants themselves, but rather their remnants (like fossilized remains) or the knowledge derived from them.

Let me know if you have any other questions!