(a) Summary tree of orders forming a soft polytomy at the base of the arachnids, based on References 8, 35, 58, 74, 75, and 78. Dotted lines reflect unstable relationships.

(a) Summary tree of orders forming a soft polytomy at the base of the arachnids, based on References 8, 35, 58, 74, 75, and 78. Dotted lines reflect unstable relationships. Solid circles on nodes ...

Pterosaurs, remarkable for their extensive evolutionary history and role as the first vertebrates to achieve active flight, have long intrigued paleontologists and the public alike. Spanning over 150 ...