SAO PAULO, March 18 (UPI) -- Only a fraction of the world's animal species have been identified and finding and naming the rest could cost about $263 billion, a Brazilian study estimates.
About 1.4 million species have been catalogued, leaving an estimated 5.4 million unknown to science, two researchers at the Universidad de Sao Paulo write in the journal Trends in Ecology and Evolution.
Fernando Carbayo and Antonio Marques say the main stumbling block to identifying the unknown creatures is a shortage of qualified taxonomists -- biologists who identify organisms and place them within related groups, LiveScience.com reported Friday.
For their global estimate they used the costs associated with describing new species in Brazil, a country with high biodiversity and an active species-identification community.
Vertebrates, with about 62,000 species known so far, have received much more attention, and half the world's taxonomists focus on them. However, the researchers said, vertebrates are estimated to make up less than 4 percent of the world's unknown animal species.
Insects dominate both the known species and the estimated number of unknown species, and the need for taxonomists specializing in them is enormous, the researchers write.
Even then, they say, "a complete inventory of the animal diversity of the world might remain an elusive goal."