This asset was created based on the National Geographic Magazine article that shares the same title. Written by Hillel J. Hoffman, the article offers insights into the author’s interactions with paleontologists and scientists while exploring the Black Triangle and Karoo regions. The primary goal is to uncover a deeper understanding of the Permian extinction and its subsequent consequences.
"Welcome to the Black Triangle," said paleobiologist Cindy Looy. A paleobiologist studies ancient life by looking at fossils and rock layers. Our van stopped in the gentle hills of the Czech Republic. The Black Triangle gets its name from the coal burned by nearby power plants. Decades of acid rain from power plant emissions have devastated the region's ecosystems. For months I'd been on the trail of the greatest natural disaster in Earth's history. This disaster happened about 250 million years ago, at the end of the Permian period. Something killed off 90 percent of the planet's species. Less than five percent of the animal species in the seas survived. Nearly all the trees died. Looy had told me that the Black Triangle was the best place today to see what the world would have looked like after the Permian extinction. We saw the first signs of death as we walked into the hills — hundreds of fallen logs lay in the grass. No birds called, no insects hummed. "The forest that grew here a few decades ago contained dozens of species of plants," said Looy. "Now there are only a few grassy species." Still, I was surprised by how healthy and green the treeless hills appeared. The Greatest Murder Mystery Of All Time She is like a homicide detective. "You could say we're working on the greatest murder mystery of all time," she said. Her theory? She believes the Permian extinction was caused by acid rain and a massive release of volcanic gases. Looy is one of many scientists on the case. They are trying to identify the killer responsible for the largest mass extinction that ever struck the planet. To understand this extinction, I wanted first to get a sense of its scale. For that, I had to go to South Africa. I joined Roger Smith, a paleontologist at the South African Museum, and we drove across a treeless stretch of land known as the Karoo. If we had driven here before the Permian extinction, we would have seen animals as abundant and varied as those in today's Serengeti. Most would have belonged to a group known as synapsids. They looked like a cross between a dog and a lizard. Smith slowed and rolled down the window. He pointed to a cliff with horizontal bands. He explained that the fossil record here dates from the transition between the Permian and Triassic periods. The fossils embedded in the rock indicate that synapsids took a savage hit at the end of the Permian. Their fossils are abundant on the lower layers. Higher up, though, they grow fewer and disappear. Sudden Tree Death Plants were also hit by the extinction. I joined a research team in the Italian Alps led by Henk Visscher of the University of Utrecht. We visit exposed fossil beds revealing the transition of the Permian to the Triassic. Here researchers show me the evidence. Lower levels of the fossil record contain lots of pollen of conifers from before the extinction event. In rocks from the Permo-Triassic boundary, however, the pollen has disappeared, replaced by fossilized fungi. "We think it's a wood-decaying fungus," says Looy, who works with Visscher. "When a tree dies, it falls. As it decays, fungi grow into it from spores on the ground, decomposing it." Visscher's team has found high levels of these fungal remains in Permo-Triassic rocks from all over the world. Their conclusion: nearly all the world's trees died suddenly. There is a great deal of evidence of the Permian disaster, but what was the culprit? Gregory Retallack is a geologist at the University of Oregon. Based on his study of ancient rock layers, his prime suspect for the Permian extinction is an asteroid smashing into the Earth. A team of researchers recently found what may be that impact's footprint below Australia: a 120-kilometer-wide (75-mile-wide) crater. The impact would have sent billions of particles into the atmosphere, Retallack says. The sun would have been blocked out for months and temperatures would have dropped. This would have killed plants and photosynthetic plankton, the base of all food chains. Herbivores would have starved, as would the carnivores that feed on them. More Than One Killer? Other Permian investigators suspect the killer oozed up from the sea. For years scientists have known that the deep ocean lacked oxygen in the late Permian. Most life was concentrated in shallow water. In 1996, English geologists Paul Wignall and Richard Twitchett reported a discovery. They found evidence of decreasing oxygen, or anoxia, in rocks that formed under shallow water at the time of the extinction. Anoxic water could have built up and smothered marine life. Another leading suspect is volcanic activity. Eruptions spread a kilometers (miles) deep layer of lava across Siberia. As volcanic gases poured into the skies, they would have generated acid rain. Particles would have blocked sunlight and cooled the planet. Each scientist I met left me thinking that he or she was close to solving the crime. Yet, as Doug Erwin of the Smithsonian cautioned me, "the truth is sometimes untidy." Erwin suspects there may have been several killers at the end of the Permian. Maybe several catastrophes occurred at once. Now humanity is creating a new mass extinction, wiping out countless species. Will life bounce back this time as well? I think about what I have learned in my research. I conclude that if life can survive the Permian extinction, it can survive anything.
