In South Africa's Limpopo province, a baobab tree once grew so large and stood so strong that its human neighbours chose to do the obvious: They built a pub insidethe living tree's thousand-year-old hollow trunk, which measured more than 45 metres around and enclosed two interconnected cavities.
Scientists say the tree can live up to 3,000 years old.
"The deaths of the majority of the oldest and largest African baobabs over the past 12 years is an event of an unprecedented magnitude", the study authors said. And it's no fluke, he adds.
Collating data on girth, height, wood volume, and age, they noted the "unexpected and intriguing fact" that most of the very oldest and biggest trees died during the study period. The stories note baobobs' iconic place in African history.
Overall, five of the six largest baobabs either died or their oldest parts significantly deteriorated. The tree started to split in 2016 and collapsed completely the following year.
None of the trees showed obvious signs of infection, the researchers found, and the pattern of deaths did not fit what would be expected had the die-off been caused by a contagious disease.
Until late previous year, the Platland tree in South Africa, also known as Sunland, was their queen.
Southern Africa, where the researchers cataloged the trees, has already been heating up faster than the global average, and researchers with the Intergovernmental Panel on Climate Change (IPCC) say the region will see some of the most intense temperatures hikes and reduced rainfall on the continent.
The baobab tree is a natural icon of the African savannah.
"We suspect that the demise of monumental baobabs may be associated at least in part with significant modifications of climate conditions that affect southern Africa in particular", Dr. Adrian Patrut of Babes-Bolyai University in Romania, who led the team, told BBC News. The baobab puts out new stems in the same way that other trees grow new branches.
The authors note in their paper that more evidence is needed to determine whether climate change is indeed the cause of the die-offs.
Despite their hardy character, baobabs need water just like any other plant, and southern Africa has become hotter and dryer in recent years.
The contention is that the largest baobabs weave together multiple tree stems around a small "false cavity", and this is what gives them their unique structure.
Patrut believes the trees are under pressure by rising temperatures and unforgiving droughts. "Climate change certainly seems like a possible (or likely) contributor". They have been surveying the trees since 2005 and have developed a theory of how they grow, while also documenting the losses.
The baobab tree, sometimes called the Tree of Life, has an unforgettable appearance.