Middle Jurassic rock located in far western Cuba are famous for fish fossils, but have also yielded the remains of Nesodactylus hesperius. Known from a single specimen collected in 1918, the limestone block was thought to contain fish bones and nearly forgotten for 50 years in the collections of the American Museum of Natural History in New York. The material was further prepared with acid in the 1960s and it was only then that scientists discovered the bones belonged to a pterosaur. It was first named and illustrated by paleontologist Ned Colbert in 1969 who noted it was only the second named pterosaur species from the Jurassic of the Americas. The name translates to “island finger from the west” referencing its discovery on the western end of the island of Cuba.
The specimen is largely complete, although disarticulated and missing most of the skull. It’s embedded in several blocks of limestone that have been partially dissolved with acid to get to the bones. The bones are extremely delicate and further preparation of the specimen is impossible without destroying it. Many bones are difficult to see or interpret because they are obscured by other bones or the limestone matrix.
The skull is only known from the right quadrate and a few other fragments. The quadrate is in the back part of the skull near the ear and jaw joint. Most of the remainder of the skeleton is present, but details of many vertebrae are hard to see. The limb bones are extremely similar to Rhamphorhynchus, but had proportionally longer legs. Like Rhamphorhynchus, Nesodactylus had a long tail, possibly with a vertical vane at its tip. When alive, this individual had a wingspan of about 120 cm (4 feet).
Colbert considered Nesodactylus to be closely related to Rhamphorhynchus, known from Upper Jurassic rocks in Germany. Later phylogenetic analyses have confirmed that Nesodactylus, along with contemporaneous Cuban pterosaur Cacibupteryx, is a close relative of Rhamphorhynchus. Rhamphorhynchids were common fish-eating pterosaurs in the Middle and Late Jurassic skies around the world.
At the time Nesodactylus was alive the western part of Cuba was on the southern shore of the newly-formed Gulf of Mexico. The geology of the Caribbean is complex, and much of the rest of Cuba and the Greater Antilles as well as Central America formed as islands in the Pacific Ocean. As North and South America moved westward, these islands slipped into the gap between the continents.