Paleontologists from Curtin University and elsewhere have examined ancient fossil eggshells of Madagascar’s extinct elephant birds and found that genetic differences in these gigantic birds, which reached 3 m in height and weighed over 500 kg, were linked to eggshell thickness, location, and diet.
“The elephant birds of Madagascar were large, flightless ratites that became extinct around a millennium ago,” said Curtin University researcher Alicia Grealy and her colleagues.
“The relatedness of elephant birds to other birds remained a mystery until several genetic studies discovered that they are sister to New Zealand’s kiwi, revolutionizing our understanding of avian diversification.”
“However, the biodiversity and evolutionary relationships within elephant birds have been uncertain and unstable since they were first described over 150 years ago, as most species are known only from few incomplete Pleistocene-Holocene skeletal remains from south and central Madagascar.”
“About eight species of elephant birds across two genera were generally accepted based on morphological comparison of skeletal fossils, but a recent morphometric re-evaluation of skeletal material reclassified elephant birds into four species across three genera (Aepyornis, Mullerornis and a new genus, Vorombe). However, this revision remains questionable.”
In the study, the authors collected and examined over 960 elephant bird eggshell fragments from 291 localities across southern, central, and, for the first time, northern Madagascar.
The specimens were between 1,290 and (at least) 6,190 years old, and were contemporaneous with most previously dated bone specimens from these areas.
Molecules preserved in some of the eggshells helped the team discover a potentially new sub-species which lived in the top end of the country.
The researchers were also able to determine that different species ate a mixture of grass, shrubs and succulents.
“Another surprising finding is that…
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