When dinosaurs became birds: studies of prehistoric Chinese fossils paint a picture of transition moment in evolutionary change

The birds, called Jeholornis, were some of the first animals to diverge away from dinosaurs and become birds

Scientists found the birds could have been fruit eaters with a strong sense of smell that were most active during daytime

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A reconstruction of a Jeholornis fossil and an artistic rendition of the bird. Photo: SCMP composite

Published: 6:00pm, 30 Oct 2022

It is common knowledge that birds are the evolutionary descendants of dinosaurs, with one of the more interesting moments in prehistoric biology being the years when the two crossed over and lived side-by-side.

Two recent studies from an international team of scientists consisting primarily of the same people shed light on the lives of a genus of birds that was one of the first to evolve away from the dinosaurs.

Called Jeholornis, this genus of prehistoric birds was about the size of a raven but was likely more colourful and featured a long bony tail with beautiful plumage feathers.

In a study published in October, the scientists used three-dimensional technology to recreate the skull of a bird that had been housed in a museum in Shandong province in eastern China. In the words of study author Jingmai O’Connor from The Field Museum of Natural History in Chicago in the US, the bones “were kind of like the bottom of a bag of potato chips”.

An artistic rendition of Jeholornis birds living in their environment. Credit: Illustration by Yezi

They discovered that the bird likely had a far more robust sense of smell than modern birds. They believe this is due to larger olfactory bulbs in the reconstructed skull, which are a part of our brain that receives neural inputs from our sense of smell.

Hu Han, the study’s lead author from the department of earth sciences at the University of Oxford, told the South China Morning Post: “We could not determine if this [sense of smell] is a key feature during hunting or mating. It is very difficult to predict this kind of relationship between one or some characteristics in fossils, especially considering that fossil birds are even rarer than other fossil animals.”

When dinosaurs became birds: studies of prehistoric Chinese fossils paint a picture of transition moment in evolutionary change

The birds, called Jeholornis, were some of the first animals to diverge away from dinosaurs and become birds Scientists found the birds could have been fruit eaters with a strong sense of smell that were most active during daytime

The birds, called Jeholornis, were some of the first animals to diverge away from dinosaurs and become birds

Scientists found the birds could have been fruit eaters with a strong sense of smell that were most active during daytime