|Bakhurina N. N. and Unwin D. M., 1995, The evidence for 'hair' in Sordes and other pterosaurs, Journal of Vertebrate Paleontology 15(3, Suppl.): 17A|
|Yang Z., Jiang B., McNamara M. E., Kearnes S.
L., Pittman M., Kaye T. G., Orr P. J., Xu X. and Benton M. J., 2019,
Pterosaur integumentary structures with complex feather-like branching,
Nature Ecology & Evolution, 2018; 3 (1): 24
D'Alba L., 2019, Imaging of pterosaur skin reveals evidence of coloured feather-like structures, but whether these are homologous with true feathers is open to debate, Nature Ecology & Evolution volume 3, pages12-13
This type of fibre is found to be a hair like structure with a hollow centre. There hairs are found in association with many areas of the skin of pterosaurs and similar structures are found in some dinosaurs. They would have been able to insulate to protect against heat and cold.
and 3 - Radially and symetrically branching feathers
Found on the head, neck and limbs. These feathered hairs probably had streamlining and insulating properties.
|Type 4 -
Bilaterally branching feathers
These are wing fibres and they were most likely able to laminate airflow over the wings. In birds, the contour wing feathers are sensory and able to detect a localised wing stall. These feathers may also have been capable of sensing airflow changes over the wings.