Mammoths get all the attention. Like an annoying younger sibling, they hog a limelight that should be more equally shared. Occasionally, the mastodon gets a whisp of publicity, which is notable mostly for its rarity. The vast family of proboscideans barely get a look in. When did you last hear any news about exciting new finds of Stegodon or Cuvieronius or Sinomastodon or Notiomastodon or Stegomastodon? What about Palaeoloxodon?
I thought so.
Palaeoloxodon antiquus should be better known. This species, also called the straight-tusked elephant, was found all over Eurasia during the warm periods of the Pleistocene. Even in Britain. We’ve got bones of this giant from interglacial gravels underneath Trafalgar square, on the east Anglian coast, and from right under the route now taken by the Channel Tunnel rail link. In Europe, Palaeoloxodon even submarined its way to some of the Mediterranean islands and evolved into unique, teeny-tiny forms on the islands of Malta, Cyprus, Tilos, and Sicily (mammoths did something similar on the island of Crete). In fact, if you close your eyes and squint real hard, there is some controversial evidence that these dwarf elephants may have squeaked into the historical period. A very interesting panel from the tomb of Rekh-Mi-Re, an 18th dynasty vizier, buried in Thebes, shows what appears to be a fully mature elephant with tusks, but only waist high. Could it have come from a Mediterranean population? Possibly, but it could also just be a stylistic convention. We don’t have a good idea of when the insular elephants went extinct but it was most likely sometime during the middle Holocene, with some perhaps hanging on until the Bronze age.
We do have a better idea of when the fullsized straight-tusker disappeared. It seems to have been widespread during the height of the last interglacial when temperatures were comparatively balmy. It shared the European landscape with hippos (Hippopotamus amphibius), Merck’s rhino (Stephanorhinus kirchbergensis) and other typically warm-adapted fauna. It probably wasn’t as hirsute as its woolly cousin and it’s helpful to picture the living animal as an Asian elephant on steroids. Four metres to the shoulders, longer tusks, just
mammoth, mastodonic, huge overall. When the climate started to cool again, it probably retreated to some of the classic Pleistocene refugia: Iberia, Italy, perhaps the Balkans too. Some evocative footprints attributed to P. antiquus have been excavated in Portugal from fossilised sand dunes. However, even these regions weren’t warm enough and the mainland straight-tusked elephant was probably gone by the end of the Middle Pleistocene. Although, having said that, there are radiocarbon dates for late Pleistocene Palaeloxodon in Portugal, but these haven’t convinced everyone. Even more fringe is the idea that straight-tusked elephants were roaming China during the historical period. This is based on analysis of bronze artefacts which show elephants with unusual trunk features. But again this could just by stylistic convention.
Right from the start, researchers have been pretty clear about where the affinities of P. antquus lay. It started off as Elephas antiquus; Elephas is the genus of the Indian elephant (Elephas maximus). However, as is its wont, ancient DNA has now come along and mixed things up a little. This week Meyer et al. published Palaeoloxodon antiquus mitochondrial genomes and nuclear DNA from Germany and it has turned things on their head. Despite reams of morphological data suggesting the straight-tusker and the Asian elephant were sister species, the DNA data puts Palaeoloxodon squarely with the African elephants. Not only that but it puts it as sister to the African forest elephant, Loxodonta cyclotis. This means that there is more genetic distance between the African savannah elephant (L. africana) and the African forest elephant that are found today, than there is between the forest elephant and Palaeoloxodon antiquus.
This is important. If you’ve paid any attention to the news recently then you know that elephants are in serious trouble. As in, we are killing them all. Poachers and ivory traders don’t give a shit about the difference between savannah and forest elephants, but we should. The destruction of wild elephants may be pushing forest elephants to the brink of extinction yet we can still look at the savannah elephants and think we have time to save them. We don’t. The continued loss of forest elephants represents the loss of a distinct lineage that needs to be recognised as a different species. Hopefully the reshuffling of Palaeoloxodon will help to show that the two African elephants are distinct, unique species and conservation measures can be tailored to their distinct, unique needs.
Written by Ross Barnett (@DeepFriedDNA)
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