By Jonathan Duffy
BBC News Magazine
While no corner of Earth remains uncharted, there are still millions of species that have yet to be discovered and documented. The quest to complete a comprehensive directory of all life on Earth goes on.
It's a good job monkeys don't understand us, else you'd fear for the newly discovered Callicebus aureipalatii.
The creature is one of about 30 varieties of titi monkey which can be found in the dense tropical rainforests of South America. There's Callicebus brunneus (Brown titi), Callicebus personatus (Masked titi), Callicebus moloch (Dusky titi) and then there's the new arrival, Callicebus aureipalatii - Golden Palace titi.
This latest species had the dubious fate of being discovered in an era of strident global capitalism - hence its name, the result of a charity auction eventually won by the online gambling emporium GoldenPalace.com.
Novelty names aside, though, it's surprising that on a planet which has been so comprehensively researched, circumnavigated and trampled over there are still new sorts of primate which have evaded human detection.
David Attenborough plants a Wollemi pine at Kew
Elsewhere, recently, there have been reports of:
This week, the Royal Botanic Gardens in Kew in London, UK, announced plans to recolonise the globe with the Wollemi pine, a tree that was thought to have died out at least two million years ago, before it was discovered by accident in 1994 in Australia.
- a new species of fox in Indonesia;
- a hitherto unknown "vampire" fish in the Amazon;
- and a long-lost ivory-billed woodpecker in the US.
While Mother Nature wrestles with the effects of industrialisation, prompting fears about extinction rates, there are still huge gaps in our knowledge about the natural world that surrounds us.
In fact, even by conservative estimates, there are more living species on the planet that haven't been identified and documented than have.
For 250 years taxonomists - biologists who specialise in identifying and classifying life - have been busy conducting a sort of stock-take of the world's seemingly countless species.
The current tally, from the tiniest plankton to the mighty blue whale, hovers around the 1.75 million mark.
But even that's just an estimate. The Catalogue of Life programme, a UK-US partnership, is consolidating all the various specie databases around the world, with the aim of producing a single, definitive directory of life.
The task should be completed by 2011, when the catalogue will then begin to absorb all subsequent discoveries - of which there are many thousands every year.
In the animal kingdom alone there are 15,000 to 20,000 new species identified annually. But barring the odd South American monkey, few of these have the sort of mass appeal that would prompt an online bidding war for the right to name them.
THE KNOWN UNKNOWNS
Carolus Linnaeus established the standard form for cataloguing species (using Latin names) in 1753
The UN Global Biodiversity Assessment proposed a working estimate of 13.6m species
There are about 830,000 logged insect species, and 50,000 vertebrates
"Over the past 10 to 15 years there have been a host of surprises as we explore previously inaccessible habitats," says Professor Frank Bisby, of Species 2000, a partner in the Catalogue of Life project.
"High in the atmosphere, deep in the soil, in the thermal vents on the ocean floor and within animals themselves, there are new species to be found."
He notes a recent discovery of 200 new species of yeast found living in the guts of beetles.
The tropics are widely acknowledged as fertile ground for all forms of life, but only now are biologists starting to seriously explore rainforests at canopy (treetop) level, and finding new varieties of wildlife.
Oceans, too, are a rich seam of undocumented life - the Census of Marine life uncovered 500 new species of fish in the first three years of this decade. It estimates there could be 10 times more waiting to be logged.
By comparison, the plant world is more familiar. About 75% of the world's plants have been chronicled, says Simon Owens, of Kew Gardens, and about 2,000 new species are discovered every year.
New Guinea, the world's second biggest island, is viewed with the sort of pioneering spirit that botanists once had for Madagascar. There's also a lot of interest in the jungles of central Africa, although civil wars have hampered further exploration.
Political changes in the old communist world have helped clear a path for Kew's army of freelance researchers, says Mr Owens, who notes some beautiful new discoveries of slipper orchids - which have a pouch rather than a lip - in remote parts of China.
The blood-sucking "vampire" fish, found recently in the Amazon
While such discoveries may delight the human eye, the overall challenge of charting the undiscovered world stretches way into the future. One study estimates that at the past rate it will take another 1,500 to 15,000 years to complete the global inventory of life.
But the pace is stepping up, says Dr Andrew Polaszek, of the International Commission on Zoological Nomenclature, thanks to the internet, rapid exchange of high quality images and DNA sequencing - which is faster than the traditional technique for documenting species.
All of which begs one last question - why bother? After all, these unknown species have existed for thousands, sometimes millions of years without occupying a line in a notebook.
In a globalised world, says Dr Polaszek, nothing can cross international barriers without a name and official documentation. Plants and animals have numerous benefits, such as helping us conquer diseases.
If we don't know something exists, we won't know when it's on the verge of extinction.
And in a globalised world, species can quickly thrive in areas where there are no natural predators, killing indigenous life.
The discovery of a species of parasitic wasp (each no more than 1mm in length) is promising to bring under control a plant killing white fly on the Canary Islands, says Dr Polaszek.
"We're almost there," says Dr Polaszek. "The wasp has been identified, and shipped over. It's in quarantine and about to be released any day now."