Timeline of pterosaur research

[1] The formal study of pterosaurs began in the late 18th century when naturalist Cosimo Alessandro Collini of Mannheim, Germany published a description of an unusual animal with long arms, each bearing an elongated finger.

He recognized that this long finger could support a membrane like that of a bat wing, but because the unnamed creature was found in deposits that preserve marine life he concluded that these strange arms were used as flippers.

[4] Similar animals like the long-tailed Rhamphorhynchus and Gnathosaurus were soon discovered around Europe and it became obvious that earth was once home to a diverse group of flying reptiles.

[6] Later in the 19th century pterosaurs were discovered in North America as well, the first of which was a spectacular animal named Pteranodon by paleontologist Othniel Charles Marsh.

Samuel Thomas von Soemmering ignited a multi-century debate over how pterosaurs walked on the ground by suggesting they crawled on all fours like bats.

[8] In the early 20th century, Hankin and Watson in the first major study of pterosaur flight biomechanics concluded that on the ground these reptiles were altogether helpless and could only scoot along on their stomachs like penguins.

[9] The debate gained steam in 1957 when William Stokes reported unusual tracks left by a four-footed animal he suspected was a pterosaur walking along the ground.

According to folklorist Adrienne Mayor, these supposed arrowheads were likely fossil belemnites, which were compared to missiles by other indigenous American cultures, like the Zuni people.