Feather Types (IMAGE) The University of Hong Kong Caption Pterosaurs had at least four feather types: filaments, filament bunches, tufted filaments and down feathers. Scale bars in photos a-d are: 100μm, 200μm, 500μm and 1mm. Credit @Zixiao Yang Usage Restrictions Please credit @Zixiao Yang when using the image. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.