The DinoBase Public Forum

Following a recent conversation with my friend and colleague Corwin Sullivan about the 'boundary' between fossils and sub-fossils and where palaeontology becomes zoology, he offered to write a post on the subject for DinoBase. I happily agreed and so this is Corwin's take on the subject. These kinds of lines are of course either blurred to the point of non-existence or arbitrary to the point of impracticality but they are worthy of discussion. Anyway, over to Corwin...


"Moas are Fossil Vertebrates, but Dodos are Just Extinct"

The Sumatran rhino, Dicerorhinos sumatrensis, is a small, surprisingly hairy rhinoceros with an uncertain future.  There are apparently fewer than 300 individuals in existence, and poaching has been a severe problem in recent years. As a vertebrate palaeontologist, I suppose I should be delighted. At this rate, my field will soon have one more object of potential study.

In reality, of course, my glee at the plight of the Sumatran rhino is muted to the point of non-existence. For one thing, I can appreciate living animals at least as much as long-extinct ones, and a world without this odd, hirsute species (the only living Asian rhino with two horns!) would be a bit less rich and interesting. Additionally, and perhaps a bit less obviously, I don’t think I could really regard D. sumatrensis as having legitimately entered the domain of vertebrate palaeontology even if all of the surviving individuals were to die tomorrow of some horrible epidemic. Most of what we know about the species would still come from observations of living or very recently deceased individuals, and I’m sure there are plenty of photo and video records to keep the Sumatran rhino from receding into the mists of prehistory.

Animals that really have gone extinct in the very recent past, like Steller’s sea cows and passenger pigeons, fall into that same grey, ghostly area between zoology and palaeontology. The celebrated American naturalist John James Audubon painted the passenger pigeon, which went extinct only in 1914, and left a fairly lengthy account of its natural history (written in collaboration with the Scot William MacGillivray) in his compendious Ornithological Biography. Audubon remarked that the meat of an adult passenger pigeon “affords tolerable eating”, whereas that of a nestling “is much esteemed”. With information like that, it’s hard to put the passenger pigeon in the same category as Tyrannosaurus rex, or even the woolly mammoth.

Mammoths, of course, come tantalisingly close to the present themselves.  The very last ones, dwarfish and isolated, died out on Wrangell Island in the Russian Arctic around 1700 BC.  The great pyramid of Khufu, or Cheops, was already hundreds of years old, and the Minoan civilisation on Crete was just entering its golden age. If Egyptians had seen live mammoths, and written about them in their hieroglyphic inscriptions, I would find it difficult to think of mammoths as belonging to the sphere of palaeontology. But in the absence of such records, everything science knows about mammoths comes from the hard evidence of bones and teeth, and from the occasional specimen frozen intact in Siberian ice.

Mammoths, then, are creatures of the geological past, rather than the human present. This is even true of moas, the large flightless birds that inhabited New Zealand until they were apparently wiped out by Maori colonists by approximately 1500 AD. For Europeans, the first inklings of the existence of moas apparently came in the 19th century, in the form of scraps of Maori oral tradition and odd pieces of fossil bone. One of these fragments, the partial shaft of a femur, eventually found its way to the great English anatomist and palaeontologist Richard Owen. His claim that the femur belonged to a bird comparable in size to the ostrich was received with skepticism, but Owen lived to be vindicated by much more complete skeletal material. The fossil record of moas is rich, and it forms the basis for almost everything that is known about them today. Maoris ate moas, used their feathers to make ceremonial costumes, and perhaps even herded them to the slaughter with dogs. However, they retained no particularly detailed or accurate accounts of the giant birds, tenuous folk memories notwithstanding. Moas are lost in the past, except insofar as they can be reconstructed with the standard methods of palaeontology.

The dodo, a bird that went extinct only slightly later, presents a very different case. Dodos were of course large flightless pigeons, or at least close pigeon relatives, restricted to the Indian Ocean island of Mauritius. The island was essentially uninhabited until the Dutch established a colony in 1598, although Arab, Malay and Portuguese sailors had all visited previously. Once Mauritius had been colonised, however, the Dutch and their domestic animals were no kinder to the dodo than the Maoris of New Zealand had been to the moa. By 1700, in all probability, the last dodo was dead, and a fascinating, improbable species had slipped into extinction. Unlike the moa, however, the dodo survives in contemporary artistic depictions and written accounts extending back to the notes of the Dutch Admiral Van Neck in 1598. The accuracy of many of these historical sources is at best questionable, but they nevertheless bring the dodo to life with a vividness and clarity far beyond what can be achieved for moas or woolly mammoths. Even more importantly, they serve to lift the dodo out of the prehistoric shadows, and into the light of recorded history. Dodos were seen, discussed, and quite probably eaten by people whose names and works survive to the present day, and they were as much a part of the seventeenth century as Oliver Cromwell or William Shakespeare. In my humble and entirely subjective opinion, moas and mammoths are good fossil species, and proper grist for the mills of vertebrate palaeontology. But dodos, like passenger pigeons, aurochs, Tasmanian wolves, and a host of others, are modern animals that just happen to have suffered the indignity of extinction.