Scientists in Japan say that their research suggests that some members of the largest species of flying reptiles could fly only a short distance.
The reptiles, known as pterosaurs, lived in the dinosaur-era.
They lived on earth until 66 million years ago and were believed to fly by soaring on updrafts in the same way as modern large birds do.
A group of researchers from the graduate school of Nagoya University and other institutions conducted aerodynamic analysis of pterosaurs to see how they could soar and glide.
The researchers used a model and calculated the performance of soaring for different species based on estimated wing sizes and body weights. They compared the data to that of modern day birds.
The study suggests that Pteranodon with an estimated wingspan of five meters could soar high on updrafts and fly freely.
On the other hand, Quetzalcoatlus, the gigantic flying reptile, could not fly so far because of the extra load on their wings. Quetzalcoatlus is presumed to have a wingspan of 10 meters and weighed about 250 kilograms.
Researchers say Quetzalcoatlus and other similar sized pterosaurs were likely to spend most of their time on the ground.
Designated Assistant Professor Goto Yusuke said while people may imagine that large pterosaurs were freely flying around, that may not be the case.
He said the results of the analysis could prompt a rethinking of the ecology of pterosaurs.