First DNA recovered from extinct Sicilian dwarf elephant

Soem 200,000 years ago, Sicily was home to two different miniature elephants, Palaeoloxodon mnaidriensis and the Sicilian dwarf elephant (Palaeoloxodon falconeri). The first species is closely related to the modern Asian elephant. The second to the straight-tusked elephant (Palaeoloxodon antiquus), an extinct species of elephant that roamed Europe and Western Asia during the Middle and Late Pleistocene (781,000–30,000 years BP).

Now, for the first-time, researchers have been able to extract and delve into the DNA of one of these extinct elephants, helping to show how the largest land mammal ever to exist shrank by at least 8,000 kilograms to become one of the smallest elephants[1].

The tiny elephants that once livedon Sicily and Malta were some of the smallest elephants ever to have existed, but quite extraordinarily they are descended from one of the biggest land mammals ever to have lived: the straight-tusked elephant.

These animals were genuine giants, with some individuals reaching up to 4.5 metres tall and tipping the scales at 14 tons. An adult straight-tusked elephant could very easily have rested its chin on the back of a bull African savannah elephant.

But new research is revealing that it took a surprisingly short period of time for this miniaturisation to occur, perhaps just 40 generations for the huge ancestors to shrink to the tiny islanders.

Co-author of the study, Dr Victoria Herridge, explains 'We have sequenced the mitochondrial genome from one of the skulls of an elephant from Puntali cave in Sicily. This is amazing, because up to now there has been no DNA evidence at all from any of the southern European population of straight-tusked elephants. We've only had ancient DNA from German specimens.'

This is largely due to the environments in which the fossils were preserved, with the heat and humidity making it exceedingly difficult for any DNA to survive. The team were able to extract and sequence DNA from the petrous bone, a small and very dense bone found in the base of the skull.

The results have shown that the straight-tusked elephant lineage that led to the dwarf elephants on Sicily actually split away from the German elephants around 400,000 years ago, even though these miniature elephants are only thought to have been isolated on Sicily within the last 200,000 years.

This is intriguing because it suggests that in the gap between these dates, there was something interesting going on with the populations of these giant herbivores within continental Europe, perhaps a divide between those living in the north and those in the south.

[1] Baleka et al: Estimating the dwarfing rate of an extinct Sicilian elephant in Current Biology – 2021