Wikipedia
Mecistotrachelos is an extinct genus of gliding reptile. The type and only known species is M. apeoros. This lizard-like animal was able to spread its ribs and glide on wing-like membranes. Mecistotrachelos had a much longer neck than other gliding reptiles of the Triassic such as Icarosaurus and Kuehneosaurus. It had unusual feet that may indicate its lifestyle as an arboreal insectivore. Two or three of the elongated ribs are very thick; though light bones are necessary for gliding, these thick bones may have supported muscles for more control in gliding.
Two fossils were excavated from a quarry on the Virginia- North Carolina border. The first fossil was found in 1994 and the second fossil eight years later by Nick Fraser, a vertebrate paleontologist at the Virginia Museum of Natural History. Both were in poor condition, and the description of the species relied on CT scans. The relationships of Mecistotrachelos are unclear, but Fraser considers that it is probably related to the protorosaurs such as the Tanystropheus, which had a neck longer than the length of the body and tail combined.