Longipteryx chaoyangensis was a prehistoric bird living about 120 million years ago in what is now northeastern China. It was part of the enantiornithes, the dominant group of land birds from the Cretaceous (145 to 66 million years ago). Longipteryx had some peculiarities, such as its elongated beak with teeth at its end. When it was first described in 2001, mention was made of its resemblance to today’s Kingfisher. Indeed, both show long wings and small legs perfect for perching.
It doesn’t take much for the following studies to equate it with a fish eater. However, its reduced number of teeth does not correspond to the dental evolution observed in piscivorous birds like Yanornis et Ichthyornis. In 2015, new research spotted crenellated teeth on a specimen, typical of a carnivorous diet. Longipteryx Did it feed on small vertebrates? This was without counting two studies published in 2023, concluding after multiple statistical analyzes that it was an insectivorous bird. But on September 10, 2024, a final paper came to provide solid evidence of the fruit-eating diet of Longipteryx. So, is the debate finally over?
photo credit: Credits: Danny Ye – shutterstock A model of Yanornis exhibited at the Shanghai Natural History Museum, China. Credits: Danny Ye.
Longipteryx: a fruit-eating bird, but not only that…
The latest study on Longipteryx is to be attributed to Jingmai O’Connor, associate curator of fossil reptiles at the Field Museum in Chicago (United States), and her colleagues. A research whose result comes from a discovery made by Jingmai O’Connor at Shandyong Tianyu Museum of Nature from Pyngyi (China). Nothing less than the largest dinosaur museum in the world according to Guinness World Records from 2010, extending over more than 28 square kilometers!
“During my first visit, I ended up with a horrible headache from trying to assimilate everything I saw,” recalls the curator. “Since then, I have returned whenever I need to understand something specific to a particular species. And when I walk among the collections, I take notes.” This is how, while reading her notebook, she came across two specimens of Longipteryx showing preserved stomach contents…
“I don’t know how I couldn’t immediately notice their importance. Especially since Longipteryx is one of my favorite birds! “, exclaims Jingmai O’Connor. She then called on her colleague Fabiany Herrera, associate curator of fossil plants at the Field Museum. His expert eyes immediately make the connection between the small round structures present in the stomach of fossils and the seeds of an ancient tree, cousin conifers and current gingkos. Longipteryx therefore ate fruits, or rather fleshy seeds – flowering plants were just beginning to appear at the time of Longipteryx.
“The fruits do not stay long in the animal’s stomach. The fact of observing remains in two individuals points to a mainly fruit-eating diet, but not exclusively,” specifies Jingmai O’Connor. Indeed, the temperate climate of the time did not allow fruit to be produced all year round. Longipteryx certainly followed a mixed diet, possibly supplemented by insects.
photo credit: Branislav Cerven – shutterstock
Despite its resemblance to the Kingfisher, Longipteryx was not piscivorous. Credits: Branislav Cerven.
A long, toothed beak made for fighting
And Longipteryx was above all a frugivore, so what was its particular beak used for? The solution could come from Jingmai O’Connor’s doctoral student, Alex Clark, at the University of Chicago. By comparing Longipteryx with the Hummingbird from Ecuador, he noted the resemblance between their two beaks, except that the teeth are replaced by projections of keratin in the hummingbird. However, “they use the end of their beak to fight among themselves.
This behavior has evolved at least seven times independently in hummingbirds, and even more in all birds,” says the curator. This same type of weapon could have evolved among Longipteryx as a result of social or sexual selection pressure. The thick enamel that its teeth display would then serve to strengthen them during the impacts of combat.
The study carried out by Jingmai O’Connor’s team highlights the importance of diet in an animal’s ecology. It reflects the direct interactions of an animal with other organisms and alters both its morphology and its behavior. But for birds, it remains difficult to define… “They can have very complex diets due to the enormous energy demands imposed by flapping flight,” recalls the curator.
Having no hands, birds use their beaks to interact with their environment. It can therefore play many distinct roles. “ Longipteryx has characteristics typical of carnivores, with large curved and crenellated teeth. And yet, it turns out that he was eating fruit,” says Jingmai O’Connor. It is therefore essential to reason carefully when trying to determine the diet of animals that have been extinct for a long time.
