Animals that sit atop the food chain rarely go unnoticed, especially ones with retractable claws, sharp carnivorous dentition, large eye sockets and lightning quick reflexes. Madagascar's top predator — the fossa — might be the exception.

Chances are you've never heard of the fossa, a cougar-like creature that looks and acts like a large cat but is more closely related to the mongoose. The animal is so mysterious that some leading wildlife researchers have never heard of it.

That was the case for Mia-Lana Lührs, a wildlife researcher who now specializes in studying the fossa, before she stumbled upon the creature while working in a zoo.

"I found out about fossas only by coincidence. When I was working in a zoo, I became familiar with the European Endangered Species Program (EEP). Searching these programs on the Web, I came to the website of Duisburg Zoo where the fossa’s EEP is managed. When I saw the pictures of the fossas on that page, I was absolutely puzzled that I had never heard of this species before, although I have always been interested in carnivores. I couldn’t even tell which family of carnivore this one might belong to," confessed Lührs to mongabay.com in a recent interview about the fossa.

Since it looks like a strange cross between a cat, a civet and a mongoose, the taxonomic classification of the fossa has been a puzzle ever since the animal was first described by science in the latter part of the 19th century. Though originally placed as part of the civet family, several taxonomists throughout history have also considered the fossa a feline.

Only recently has the matter been solved, thanks to DNA evidence that suggests the fossa is actually most closely related to the mongooses. Even so, the relationship is distant enough that fossas have been assigned to their own family, Eupleridae, along with the rest of Madagascar's unusual carnivores.

It has retractable claws like a cat and is as much at home in the trees as on the ground, but the fossa is unusual in that it hunts cooperatively in packs capable of taking down large primates. Lührs believes the cooperative hunting was an evolutionary behavior leftover from Madagascar's past when giant lemurs, now extinct, would have been a favorite fossa delicacy.

Unfortunately, the fossa's status as the world's least known top predator has muted conservation efforts. Lührs hopes that raising new awareness about the animal might help spark a much-needed conservation movement in Madagascar.

"Fossas are such fascinating creatures that they should be popular all around the world despite their limited distribution," she said.

Besides the fossa, Madagascar is home to a number of endemic species, including all of the world's species of lemur. Unfortunately, much of this biodiversity is being lost at an alarming rate. Since the arrival of humans 2,000 years ago, Madagascar has lost more than 90 percent of its original forest.

"I've always been much more concerned about species that die out secretly without anyone ever knowing they existed at all. The fossa is certainly one of those species. For the sake of conservation of the world’s biodiversity, I would therefore like to encourage more researchers to focus on the 'forgotten species in the background'," said Lührs.

You can learn more about the fossa and read the full interview with Lührs at mongabay.com.