"Exceptionally rare" conjoined whale twins have been found dead in a lagoon in Mexico.
Fishermen found the grey whale calves in the Ojo de Liebre lagoon in the Baja California peninsula, which opens up to the Pacific Ocean.
The four-metre (13 feet) long creatures, which weighed nearly half a tonne, were linked at the mid-section.
They had two full heads and tail fins, according to Benito Bermudez, a marine biologist and regional manager at the National Natural Protected Areas Commission.
Mr Bermudez said the discovery was "without any precedent" in the region, which is in the nortthwest of the country.
It is believed the whales were born as the result of a miscarriage and did not survive for long.
Scientists were examining the carcasses and plan to look for other cases in the animal's habitat off the peninsula.
Hundreds of grey whales migrate from the Bering Sea between North America and Russia to the warmer waters of Baja California every year.
Almost 1,200 of them were spotted in the region during the 2012-2013 season, and their migration draws tourists to the area.
The grey whale undertakes the longest yearly migration of any known mammal, heading south to feed after breeding in the winter in the Bering Sea.
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