The cycad has survived three mass extinctions, dinosaurs and early humans, but due to today's climate change
The cycad has a rough, strong trunk and an upward tuft of tough, palm-like leaves. Its appearance is more consistent with the Late Cretaceous than with the modern world.
Cycads have been around for a very long time, but they can hardly be called living fossils. The cycads have changed a lot in their lives, and perhaps it is up to us to save them.
Although they have experienced numerousmass extinctions, today many species of cycads are endangered because of us. Humans not only change the habitat of these plants, but also trade in endangered rare cycads. Because of this, plants that have existed for millions of years may disappear.
When did cycads appear?
Cycads appeared before even the very firstdinosaurs. About 280 million years ago, a plant with a hard, scaly covering grew in what is now Brazil's Paraná Basin. Paleobotanists know this plant as Iratinia australis, the oldest known cycad.
“Many signs have been found in the fossilscycads,” says Mario Coiro of the Ronin Institute. The appearance of the first cycads on Earth is part of paleobotanical history, in which there were plants that did not look like those we see today.
"We know that cycads are related to otherinteresting plant species, for example, with seed ferns, which are now all extinct,” said Cristina López-Gallego, botanist at the University of Antiquity.
Cycads did not immediately become quickly and successfullymultiply. Plants survived the worst mass extinction that occurred at the end of the Permian period, 252 million years ago. And then they began to actively spread along with the early dinosaurs and mammals in the Triassic.
How do cycads look and work?
At first glance it may seem that cycadsnot so different from the small palm or other familiar plants. But appearances can be deceiving: cycads are technically gymnosperms—a large family that includes all conifers.
There are cones in cycads that contain themseeds are structures called stobili. They grow in the center of the crown of the plant. Some cycads are small and only a few inches off the ground, while others may be taller than a human. However, the pineapple-like shape, leaves, and cones have been a hallmark of cycads for a very long time.
How did cycads begin to spread and change?
Between 200 million years and 66 million years ago, cycads,seemingly growing everywhere and being actively eaten by dinosaurs. Paleontologists even suggested that dinosaurs contributed to the spread of cycads when they ate their fruits along with seeds.
Ancient reptiles may have carried seedscycads to new places where there was fertilizer and good conditions. Paleontologists also found images of cycads in the drawings of primitive people. Therefore, it seems that cycads have not changed at all since then, but this is not so.
In a 2011 study, a cycad expert fromRoyal Botanic Garden Sydney Natalie Nagalingum and her colleagues have discovered that cycads are responding to changes in the Earth's climate and are quickly adapting to continue to grow.
There are currently about 300 livingspecies of cycads, but most of them are no older than about 12 million years. What scientists are seeing today is a diversification of cycads that occurred much closer to the present day than to the period when these plants were eaten by dinosaurs back in the Jurassic period.
Cycads flourished in the Mesozoic, survived the massthe extinction that ended the age of the dinosaurs, and then began to develop again over the past 12 million years. They actively bred in tropical conditions with the right combination of heat and rainfall. Cycads did not depend on dinosaurs, they evolved in accordance with more global factors, such as climate change and seasons.
In fact, notes Mario Coiro of the Ronin Institute, cycads living today grow in a wide variety of places and come in a wide variety of forms—a testament to how plants have changed over time.
Why are cycads dying out?
But despite its long history, todaycycads are fighting for life. “Today the cycads are in the greatest danger. About 62% of known species are listed on the IUCN Red List - a catalog of species that are on the verge of extinction. This percentage includes dozens and dozens of species, and they got there because of us,” Lopez-Gallego said.
Cycads are disappearing for a number of reasons.Most species suffer from habitat destruction and degradation. In 2016, botanists reported that cycads from the protected genus Encephalartos were found in markets in South Africa - likely used in traditional medicine.
Many cycads are endangereddisappearances are also exported from South Africa and sold to private collectors. Cycads have survived three mass extinctions, but humans are reducing their populations much more effectively. There are conservation initiatives in Africa, the Americas, and Asia to conserve the remaining cycads. Local conservation programs, such as those in Uganda, work with researchers who live where cycads grow to help conserve the species. And research based on gene banks will help botanists grow cycads and replant them in places where they disappeared. Cycads were able to survive for 280 million years without us, but now they need our help, the researchers say.
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