A Giant Tortoise by Any Other Name: Lengthy Battle Ends with Moniker for Indian Ocean Reptile

Article excerpt

One of taxonomy's most passionately disputed arguments over a scientific name has finally come to an end. After nearly two centuries of ambiguity, years of fierce debate and a record number of formal comments on the proposed name, a commission has declared gigantea the one true species term for the Aldabra giant tortoises.

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That species descriptor will be used as part of a two word Latin name that puts the species into a genus with its near relatives. Meet Aldabrachelys gigantea.

The International Commission on Zoological Nomenclature oversees standards in the naming of animals. Naming debates can get "fractious" says executive secretary Ellinor Michel.

Confusion about the name built over centuries. Biologists have used 49 different Latin names for the giants of the Aldabra Moll in the western Indian Ocean. The tortoises can weigh several hundred pounds and live for more than a century. Taxonomic rules call for rigorously determining the earliest valid name and designating a single specimen as a benchmark "type." The naming code also calls for stability.

The issue came to a head in 2008, when Ecuador-based zoologist Jack Frazier, with the Smithsonian Institution's National Museum of Natural History, asked the commission to recognize gigantea as the valid species descriptor for the tortoise and to use a specimen he described in 2006 as the benchmark.

Frazier argued that gigantea is now the most commonly used Latin term for the species. At Frazier's urging, conservationists and other nontaxonomists who use the species name chimed in.

Normally each of the 40 or so naming disputes the commission considers in a year draws a couple of commentaries in response, Michel says. The tortoise dispute inspired more than 80 responses.

But Frazier's call for nonspecialist opinions wasn't appropriate, protested taxonomist Roger Bour of the French National Museum of Natural History in Paris. "Should zoological nomenclature be regulated by a set of rules or by 'polls' open to anyone?" he asked in a commentary he sent to the commission. The tortoise case "was initiated by non-taxonomists apparently unschooled in the rules of zoological nomenclature and unwilling to abandon a name that they have become used to."

The argument against gigantea is long and intricate. Just one of the problems: The earliest candidate for a type specimen was either lost or mislabeled for at least 90 years. …