With a beak full of ultra-strong teeth, this weird prehistoric bird may seem like a fearsome predator.
However, a new study has found that the Longipteryx chaoyangensis actually feasted on fruit rather than flesh when it lived in China 120 million years ago.
While it is often extremely hard to determine an ancient animal’s diet, scientists from the Field Museum, Chicago were able to spot fossilised fruit within the belly of this toothy terror.
This provides definitive evidence that Longipteryx did not feed on fish, as scientists had previously thought, although it might have eaten insects too.
But that does not mean that this feathered forager was harmless as the researchers believed it may have used its sharp teeth to fight other members of its own species.
Researchers have found that the ancient bird Longipteryx chaoyangensis didn’t use its sharp teeth to eat meat, but actually lived on a diet of fruit
Lead author Jingmai O’Connor, of the Field Museum, says: ‘Longipteryx is one of my favorite fossil birds, because it’s just so weird— it has this long skull, and teeth only at the tip of its beak.’
When remains of this ancient bird was discovered in 2000 beneath what is now Northwestern China, those teeth left paleontologists with quite a puzzle.
Based on its similarity to the modern-day Kingfisher, scientists initially suggested that Longipteryx might have hunted fish.
However, Dr O’Connor says that the evidence for this theory didn’t quite fit.
Since fish tend to be preserved well during fossilisation, researchers have already found several ancient birds from a similar period with bellies full of fish.
However, in all of the Longipteryx samples that had been found none had any signs of having eaten fish.
When Longipteryx (pictured) was found in 2000, researchers thought it might have used its sharp teeth to capture fish
Palaeontologists compared the ancient bird to a modern-day Kingfisher based on the shape of its long toothy beak
Dr O’Conor adds: ‘Plus, these fish-eating birds had lots of teeth, all the way along their beaks, unlike how Longipteryx only has teeth at the very tip of its beak, it just didn’t add up.’
However, while on a trip to the Shandong Tianyu Museum of Nature in China, Dr O’Connor spotted two specimens which appeared to have something in their stomachs.
On closer inspection, this turned out not to be fish or insects but the fruit from trees related to today’s modern conifers and ginkgos.
Since Longipteryx lived in a temperate climate, the researchers don’t think they would have eaten fruit all year round.
Rather, they think that they would have had a mixed diet which included insects when fruit weren’t available.
New analysis of fossils found in China reveals fossilised seeds (pictured) in the stomach of the ancient bird
Three Longipteryx fossils (pictured) were found to have eaten the fruit of trees related to modern conifers and ginkgos – providing direct evidence that they did not exclusively eat fish or insects
Dr O’Connor adds: ‘It’s always been weird that we didn’t know what they were eating, but this study also hints at a bigger picture problem in palaeontology, that physical characteristics of a fossil don’t always tell the whole story about what animal ate or how it live.’
While the researchers might have solved the mystery of what Longipteryx ate, this leaves the puzzling question of why it needed such big teeth.
Researchers found that each of Longipteryx’s teeth is coated with a layer of enamel 50 microns thick.
‘That’s the same thickness of the enamel on enormous predatory dinosaurs like Allosaurus that weighed 4,000 pounds, but Longipteryx is the size of a bluejay,’ says co-author Alex Clark, a PhD student at the University of Chicago.
Mr Clark adds: ‘The thick enamel is overpowered, it seems to be weaponized.’
While the fossils themselves don’t necessarily show how these weapons were used, scientists can turn to modern animals for inspiration.
Researchers think a better comparison for how Longipteryx used its beak is the modern-day hummingbird
Several modern hummingbirds have teeth-like projections near the tops of their beaks (pictured left), the researchers think that Longipteryx may have used its beak to fight just like the Androdon aequatorialis hummingbird (right)
The researchers point out that several modern hummingbirds have teeth-like ‘keratinous projections’ near the tips of their beaks which are used to fight other hummingbirds.
Mr Clark says: ‘One of the most common parts of the skeleton that birds use for aggressive displays is the rostrum, the beak.
‘Having a weaponized beak makes sense, because it moves the weapon further away from the rest of the body, to prevent injury.’
Since hummingbirds have evolved these toothy weapons seven different times, the researchers believe that Longipteryx may have used its teeth in a similar way.
That means that while Longipteryx may have fed itself on fruit, it may have used its beak of weaponised teeth to compete for resources such as food and access to mates.
