Mystery of 'Lemur Without a Nose' Fossil is Out

A seven million year old fossil has been a curiosity as this was only one specimen in existence and is different from other primates. This fossil is of the species known as Arrhinolemur Scalabrinii which means 'scalabrini lemur without a nose'. The lemur without a nose is in fact a fish.

Since it was first described in 1898, it has been classified as a mammal. It has also being placed among the piscatorial group. The detailed analysis of this is been produced by the scientists from Argentina, OregonState University and the Smithsonian Institution.

"The name given to the fossil back in 1898 should have given a clue that something was wrong," said Brian Sidlauskas, a fisheries expert in the Department of Fisheries and Wildlife at Oregon State University and co-author of the study. "It isn't unusual to see a species reassigned to a different genus, but you don't often see one moved to an entirely different class."

Pedro Scalabrini, a fossil collector had provided a fossil that was enclosed in a rock to Florentino Ameghino. This was later assigned it to the primate family Lemuridae where they highlighted the difference on comparision to other mammals. About a half-century later, a scientist named George Gaylord Simpson briefly reviewed the entry and proposed that the specimen was not actually a mammal, but an unidentified species of fish.

Sidlauskas and Richard Vari, an ichthyologist at the Smithsonian have together done a complete analysis of the photos and drawings of the fossil. Sidlauskas has previously written a monograph on South American fishes as part of his doctoral work at the University of Chicago. Based on their analysis they concluded that lemur without a nose is a fish of the genus Leporinus, family Anostomidae .

"It is the head of a small fish, only a couple of inches long, but it's difficult to tell what it may have grown to," Sidlauskas said. "Fish in that family can be two inches long or two feet long, and there are 150 to 200 species in the family -- all indigenous to South America."

"Clarifying the fossil record helps scientists to calibrate trees of life and better understand the biodiversity of the planet in the past and compare it to biodiversity today," said Sidlauskas, who curates the Oregon State Ichthyology Collection.

"It also helps us analyze evolutionary transitions -- we can look at in the past and compare them to similar fish today to see what features have changed over time and try to understand why."