In Depth
Though not as famous as Dinornis, the Megalapteryx genus is just as if not even more important to our understanding of moa birds.
Megalapteryx is one of the few moa, in fact one of the few prehistoric animals, to be known by mummified remains of soft tissue.
Mummification is essentially where all moisture is drawn out of soft tissue, drying it out completely.
With no moisture content, bacteria that would normally break down soft tissues cannot take hold, and so what you are left with is the original soft tissue, now hardened in the near original form to how it was in life.
The mummification of some Megalapteryx remains happened because this genus of moa is known to have lived in habitats that were as much as two thousand meters above sea level, hence the more common name of the genus, the upland moa.
At these altitudes the air is not just thinner, it is also drier, and with the addition of prevailing winds dehydrating animal remains further as they blow over them, any animal remains that are not picked clean by scavengers, have a chance of being mummified.
This phenomenon is not unique to New Zealand however, naturally mummified remains of animals and even people have been found at high altitudes at locations in Africa, Asia and South America.
On a further side note, high altitudes are not always necessary for mummification.
The famous mummies of Ancient Egypt originally started out as desert sand burials where the lack of moisture in the sand caused a similar desiccation of the body, making it mummified.
It was only later in Ancient Egyptian civilisation that bodies were artificially mummified by placing them in baths of (presumably dry) natron.
Back to moa birds, the mummified remains of Megalapteryx include body parts such as a foot, leg, head and neck (partially preserved), and skin.
Additional skeletal remains and feathers of Megalapteryx are also known. Stomach contents and coprolites of Megalapteryx have also been identified as being made up of the fresh green branches of shrubs and trees, tussock grasses and herbs associated with semi aquatic environments.
The latter is not so unusual, since high altitude streams would feed into pools and perhaps even small lakes and these may have been the only permanent sources of fresh water at such high elevations.
Uplands habitats not only have thinner air but are generally more exposed to prevailing winds, two factors that can greatly reduce the ambient temperature.
This is probably why Megalapteryx is noted for having a greater amount of feathers that also insulated the lower legs, feet, and head. Only the beak and soles of the feet were devoid of feathers.
In forest dwelling genera, the lower legs and possibly the head in some had no feathers, probably because they were living in warmer and more moist environments.
The Megalapteryx genus is also a good indicator for how moa probably did not carry their heads and necks totally erect and upright.
More modern reconstructions concerning Megalapteryx, indicate that the head was probably carried near horizontally level to the back. This would actually make more sense since most of the plants that Megalapteryx fed upon were low growing.
A neck held closer to the level of the body would also not be so exposed to prevailing winds, making it easier for Megalapteryx to maintain body temperature in the cooler climates of its habitats.
Remains of eggs of Megalapteryx are also known, and appear to have been dark olive-green in their colouration.
There is speculation though that the colour of egg shells may have varied slightly between individuals.
Megalapteryx individuals are expected to have laid about one or two eggs at a time which were then cared for by male birds.
This would hint at a K-strategy survival method where a parent bird makes a concerted effort at rearing a small number of young rather than raising many young and relying upon weight of numbers to carry the species through.
The Megalapteryx genus was originally described as a species of Dinornis, D. didinus, by Richard Owen in 1883.
Two years later this species was used as the basis for establishing the then new genus of Megalapteryx.
Like with many other moa genera, Megalapteryx was once treated as something of a ‘waste basket taxon’ and ended up with more species names than as was necessary. As of 2013 the only species of Megalapteryx recognised as valid is M. didinus.
Further Reading
- - Mummified moa remains from Mt Owen, northwest Nelson - Notornis 36 (1): 36–38. - Trevor H. Worthy - 1989.
- - Unique, dark olive-green moa eggshell from Redcliffe Hill, Rakaia Gorge, Canterbury - Notornis 39 (1): 63–65. - Beverley McCulloch - 1992.
- - Plant remains in coprolites: diet of a subalpine moa (Dinornithiformes) from southern New Zealand. - Emu Austral Ornithology - Mark Horrocks, Donna D’Costa, Rod Wallace, Rhys Gardner & Renzo Kondo - 2004
