Scientists have just been floored by an incredible new finding in China that suggests that ancient trees had hundreds of tree-like structures inside, meaning they were far more intricate and complex than modern trees. Researchers made this determination after examining fossils of trees ages at 374 million years old in northwest China, which indicated that they had interconnected woody strands inside them forming a mesh of sorts.

Scientists working on the project called the discovery “bizarre.” The specimens in questions were unearthed in 2012 and 2015 in the town of Xinjiang, and they are part of a group of trees called cladoxylopsids, which lived between 393 million to 320 million years ago, before even dinosaurs arrived on Earth.

Scientists were aware of cladoxylopsids in locations around the globe, including in Western Europe and New York state. But they weren’t as well preserved as the ones discovered in China. A cross section of those trees shows black dots throughout, and each of the dots has its own tree ring series until modern trees, which only have their own tree ring series.

“The first trees to have ever grown on Earth were also the most complex, new research has revealed,” reads the statement from Cardiff University. “Fossils from a 374-million-year-old tree found in north-west China have revealed an interconnected web of woody strands within the trunk of the tree that is much more intricate than that of the trees we see around us today. The strands, known as xylem, are responsible for conducting water from a tree’s roots to its branches and leaves. In the most familiar trees the xylem forms a single cylinder to which new growth is added in rings year by year just under the bark. In other trees, notably palms, xylem is formed in strands embedded in softer tissues throughout the trunk.”