Aepyornis hildebrandti (Hildebrandt's Elephant Bird)

[RSN]

Aepyornis hildebrandti
Burckhardt 1893
Quaternary of Madagascar
Primary materials: Type: tarsometatarsus
Secondary materials: Nearly complete skeleton

home.planet.nl/~by000012/SM/Fossil/FossilAepyorn.htm

[another specialist]

Extinct birds : an attempt to unite in one volume a short account of those birds which have become extinct in historical times : that is, within the last six or seven hundred years : to which are added a few which still exist, but are on the verge of extinction (1907)

[another specialist]

Extinct birds : an attempt to unite in one volume a short account of those birds which have become extinct in historical times : that is, within the last six or seven hundred years : to which are added a few which still exist, but are on the verge of extinction (1907)

[another specialist]

Aepyornis hildebrandti Burckhardt, 1893
=Aepyornis mulleri Milne-Edwards & Grandidier , 1894

en.wikipedia.org/wiki/Aepyornis

[another specialist]

Extinct birds : an attempt to unite in one volume a short account of those birds which have become extinct in historical times : that is, within the last six or seven hundred years : to which are added a few which still exist, but are on the verge of extinction (1907)

[another specialist]

My own photos taken in the Natural History Museum at Tring - April 30 2009

[simontonge]

This is a skeleton labelled Aepyornis hildebrandtii at Parc Tsimbazaza in Antananarivo. Whether it really is that species, or even whether A. hildebrandti actually existed, will remain a bit of a moot point until there is a modern taxonomic revision of the Aepyornithidae.

Attachments:

[Melanie]

Well Madagascar is much larger than New Zealand and so I think that there was more than one Aepyornis species on that island. If you compare the Aepyornis of Madagascar with the Moas of New Zealand you can see a good example of convergent evolution. On Madagascar there were few natural enemies for Aepyornis like the Malagasy Crowned Eagle (which probably feed on Aepyornis chicks), the crocodiles, and the Fossa. On New Zealand there were only one natural enemy for the moa, the Haast's Eagle.

[simontonge]

I absolutely agree that it is highly likely that there were multiple species of elephantbird on Madagascar. My comment was only to highlight that the current list of putative species is very old and based on taxonomic concepts that are now outdated. The extensive work on Moas over the last 20 years has affirmed the validity of most, but not all, of the species that were described in the 19th century and has shown ontogenetic, temporal and sexual variation that had not been anticipated. I fully expect that similar patterns will be shown in the elephantbirds but as far as I know nobody is studying them. What a shame.

[Peter]

Up to eight species of elephant birds have been listed in the past. But when consideration is yaken that size differences can be explained by sexual dimorphism and temporal variation, qualiative differenes support only three distinct species. These are two Aepyornis species: Aepyornis maximus (includes A. medius as its smaller sex) and A. hildebrandti (includes A. gracilis). The third species is the more gracile Mullornis agilis (includes M. betsilei and M. rudis, named on unusually small specimens, and M. grandis a larger Pleistocene variant). As here defined, the size range of these elephant birds is less than that of some of the moa species, where much larger samples and well-dated specimens are available.

Source: Worthy, T.H. (2009). Fossil Birds. In: Gillespie, R., Clague, D. (Eds.) (2009). Encyclopedia of Islands. Encyclopedias of the Natural World, No. 2. University of California Press. ISBN: 9780520256491.

[surroundx]

Hansford, James P. and Turvey, Samuel T. (2018). Unexpected diversity within the extinct elephant birds (Aves: Aepyornithidae) and a new identity for the world's largest bird. R. Soc. open sci. 5: 181295.

[Sebbe]

Early Holocene human presence in Madagascar evidenced by exploitation of avian megafauna.

Previous research suggests that people first arrived on Madagascar by ~2500 years before present (years B.P.). This hypothesis is consistent with butchery marks on extinct lemur bones from ~2400 years B.P. and perhaps with archaeological evidence of human presence from ~4000 years B.P. We report >10,500-year-old human-modified bones for the extinct elephant birds Aepyornis and Mullerornis, which show perimortem chop marks, cut marks, and depression fractures consistent with immobilization and dismemberment. Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar. This revision of Madagascar’s prehistory suggests prolonged human-faunal coexistence with limited biodiversity loss.

www.science.org/doi/10.1126/sciadv.aat6925

[Sebbe]

Bone histology yields insights into the biology of the extinct elephant birds (Aepyornithidae) from Madagascar.

Given that the biology of the recently extinct aepyornithids is poorly understood, we undertook a histological study of 29 skeletal elements of adult and juvenile specimens of Aepyornithidae, i.e. Aepyornis maximus, Aepyornis hildebrandti and Vorombe titan, in addition to a group of taxonomically unidentifiable juvenile Aepyornithiformes. Comparative analysis of the histology of the different skeletal elements showed that although the femur retained a good record of growth during early ontogeny, the tibiotarsus provided the best record of growth. Our data showed that, like other insular birds and their extant relative, the kiwi, Aepyornithidae experienced protracted growth. We also found that intracortical remodelling began early in ontogeny and continued throughout their lives, becoming more extensive throughout the compacta with age, albeit more restricted to the perimedullary region in the femora. We also deduced that the different skeletal elements experienced variable amounts of intracortical remodelling, which was most likely to be related to biomechanical constraints, size of the element and ontogenetic age. Additionally, we documented the occurrence of an unusual endosteal tissue within the large perimedullary erosional spaces of a femur of A. maximus. Overall, our study provided a lot of new information about the life history of these giant, recently extinct ratites.

academic.oup.com/biolinnean/article/130/2/268/5815707?login=false

[Sebbe]

Molecular exploration of fossil eggshell uncovers hidden lineage of giant extinct bird.

The systematics of Madagascar’s extinct elephant birds remains controversial due to large gaps in the fossil record and poor biomolecular preservation of skeletal specimens. Here, a molecular analysis of 1000-year-old fossil eggshells provides the first description of elephant bird phylogeography and offers insight into the ecology and evolution of these flightless giants. Mitochondrial genomes from across Madagascar reveal genetic variation that is correlated with eggshell morphology, stable isotope composition, and geographic distribution. The elephant bird crown is dated to ca. 30 Mya, when Madagascar is estimated to have become less arid as it moved northward. High levels of between-clade genetic variation support reclassifying Mullerornis into a separate family. Low levels of within-clade genetic variation suggest there were only two elephant bird genera existing in southern Madagascar during the Holocene. However, we find an eggshell collection from Madagascar’s far north that represents a unique lineage of Aepyornis. Furthermore, divergence within Aepyornis coincides with the aridification of Madagascar during the early Pleistocene ca. 1.5 Ma, and is consistent with the fragmentation of populations in the highlands driving diversification and the evolution of extreme gigantism over shorts timescales. We advocate for a revision of their taxonomy that integrates palaeogenomic and palaeoecological perspectives.

www.nature.com/articles/s41467-023-36405-3