A giant Galapagos tortoise believed extinct for 150 years probably still exists, say scientists.
Chelonoidis elephantopus lived on the island of Floreana, and was heavily hunted, especially by whalers who visited the Galapagos to re-stock.
A Yale University team found hybrid tortoises on another island, Isabela, that appear to have C. elephantopus as one of their parents.
Some hybrids are only 15 years old, so their parents are likely to be alive.
The different shapes of the giant tortoises on the various Galapagos islands was one of the findings that led Charles Darwin to develop the theory of evolution through natural selection.
The animals are thought to have colonised the archipelago through floating from the shores of South America.
Colonies on each island remained relatively isolated from each other, and so evolved in subtly different directions.
C. elephantopus is especially notable for its saddleback-shaped shell, whereas species on neighbouring islands sported a dome-like carapace.
Three years ago, the Yale team reported finding some evidence of hybrids around Volcano Wolf at the northern end of Isabela Island, in amongst the native population of Chelonoidis becki.
They speculated that through careful cross-breeding, it might be possible to re-create the extinct lineage - a process likely to take many generations.
Now, in the journal Current Biology, they report that this might not be necessary. A further expedition to Volcano Wolf found 84 tortoises that appear, from genetic samples, to have a pure-bred C. elephantopus as a parent.
Thirty of these are less than 15 years old; so the chances of the pure-blood parents still being alive are high, given that they can live to over 100 years old.
"Around Volcano Wolf, it was a mystery - you could find domed shells, you could find saddlebacks, and anything in between," recounted Gisella Caccone, senior scientist on the new study.
Read more at: http://www.bbc.co.uk/news/science-environment-16467397
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