Laelaps

At a meeting of the Royal Society in 1893 the English geologist Henry Woodward read a communication from his Swiss colleague Charles Immanuel Forsyth Major on a new, recently extinct genus of giant lemur from Madagascar. He called it Megaladapis, and it was a lemur with a skull as large a modern gorilla's. Particularly interesting were the thick rims of bone around its eyes which appeared to be oriented slightly upwards.

Whenever Megaladapis became extinct it could not have been very long ago. Its bone were found in a marsh that also contained bones from crocodiles, hippos, turtles, and the recently extinct elephantine bird Aepyornis. The discovery of such a strange primate was impressive in and of itself but perhaps the deposits in which it was found held some clues as to how it lived.

Even though little was known of Megaladapis when it was discovered it was apparent that it had died in a watery habitat and that it had hippo-like eyes. Could it have been aquatic? The scientist H.F. Standing, who lived on Madagascar, thought so. Its skeleton did not readily resemble those of other arboreal lemurs and the eyes, in particular, seemed to indicate that it was spending some time lurking just below the surface of the water.

Forsyth Major agreed with Standing's hypothesis. In a 1900 paper published in the Geological Magazine he wrote;

... the clumsy Megaladapis can scarcely be supposed to have been climbers at all. The remarkable shortness and flattening of the Megaladapis femur calls to mind the same bone of aquatic Mammalia ; the -elevated position of its orbit would point in the same direction.

This position was taken by British Museum of Natural History (now the Natural History Museum) in London, as well. In their 1904 Guide to Fossil Mammals and Birds the section of Megaladapis said;

[Megaladapis] clearly did not live in trees, and it may perhaps have been adapted for an aquatic life. The bony rims of the orbits are curiously produced and arranged like those of a hippopotamus.

Today we know the contrary to be true. This extinct relative of living sportive lemurs was indeed well-adapted for clambering through the trees and was not aquatic. The features that were thought to have supported this conclusion, the orientation of the eyes, ultimately fell to examinations of new evidence and the entire skeleton. (For more on this see the excellent reference work The Primate Fossil Record.)