Daubentonia robusta (Giant Aye-aye)

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Daubentonia robusta


This species was thought to have go extinct in the late 1700 but new recent information suggest that the last animals of this species was hunted as recently as the 1920 but it seems likely that the last animals was killed on east Madagascar in the early 1930. Arboreal island montane forest nocturnal insectivore endemic to Madagascar. Disappeared after hunting for fur and superstition.

[another specialist]

Daubentonia robusta

Daubentonia robusta (Lamberton, 1934) is a form that has died out recently and is only known by a postcranial skeleton (Chiromys robustus pl1a;_ Chiromys robustus pl1b) and some adult teeth. In the beginning of this century these teeth are discovered by Grandidier in the southwest of the island, mixed with bones of Aepiyornis, Megaladapis and Paleopropithecus.
These teeth have been cut and pierced with a hole to be carried as a necklace by the men or women contemporary in that fauna. They are noticeably larger and thicker and they posses a larger curvature compared to the extant forms (Grandidier, 1928).
Later Lamberton found another tooth and bones in Tsirave. These resembled those of D. madagascariensis but were of larger size: a radius of 127 mm (against 89 mm), an ulna of 153 mm (against 104 mm), a humerus of 118,5 mm (against 90 mm).
The bones indicate that D. robusta was adapted to the same ecological niche as the present form with the same feeding-specializations and in particular the modifications of the middle finger and of the front teeth (Hill, 1953).

It is possible that this form died out very recently; Lamberton reports of a communication with Hourcq, 1934, the official governor of the island, who declares that he has seen the skin of an very large animal in the Soalala district: certainly it must have been one of the last representatives of the species.

In the recent state of research it is not possible to make out whether it are the variations of the general climatic conditions, the activities of men or other factors that has made disappear these subfossils (MacPhee and Raholimavo, 1988).

www.tsidy.com/lemurs/species/species.asp?sp_name=Daubentonia%20madagascariensis

[another specialist]

Giant aye-aye Daubentonia robusta fossils are closely related to extant aye-aye D. madagascarensis.

Only limb bones differ significantly in morphology, other than it was significantly larger weighing 10kg.Utilised ‘structuraly defended’resources –nuts, seeds, fruit and insects

Fulfil the role of arboreal rodents in other ecosystems

www.shef.ac.uk/aps/level3modules/aps302/aps302-3--dj-2004.pdf

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Subfossils of a giant form of aye-aye are found at scattered sites in the south and southwest of the island of Madagascar, outside the known distribution of the living, or common, aye-aye. The subfossil aye-aye, named Daubentonia robusta, has massive, robust limb bones implying a species with a body weight 2.5-5 times as great as that of the living species. A mystery exists regarding how a species this large with the same specializations of teeth and manus as the living species could have existed in a xeric environment.

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Although only one living species of aye-aye is currently recognized, remains of a second, extinct species, Daubentonia robusta, are known from a few sites in the south of Madagascar. No skull has yet been found, but postcranial bones are larger and much more robust than those of the living form, suggesting that it was at least 2.5 times, and possibly as much as 5 times heavier. Teeth of D. robusta perforated for stringing provide one of the few direct evidences that any extinct lemur was hunted by humans, and it is virtually certain that this species was driven to extinction by human action (E. Simons, pers. comm.).

[another specialist]

source of info

homepage.mac.com/wildlifeweb/primate/PrimateWeek/AyeAye/AyeAyeWeek.html

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The Giant Aye-aye (Daubentonia robusta) lemur was somewhat larger and 2.5 to 5 times heavier than the surviving Aye-aye (see below), but in other respects was very similar (Garbutt 1999). It is known from subfossil remains found in southwestern Madagascar (Nowak 1999). The date of its disappearance is unknown but may be fairly recent.

www.endangeredspecieshandbook.org/madagascar_human.php

[another specialist]

There is also a possibility that Daubentonia’s largebrain size is in part a consequence of a secondary reduc-tion in body mass from a larger-bodied ancestor (Lamber-ton, 1934; Bauchot and Stephan, 1969; Frahm et al.,1982). The only other known species of Daubentoniidae isthe subfossil Daubentonia robusta (Lamberton, 1934), amember of a diverse array of recently extinct giant lemurs(Godfrey and Jungers, 2003) that is estimated to havebeen approximately 13.5 kg—three to five times the size ofthe extant D. madagascariensis (Simons, 1994).

www.cs.brown.edu/research/vis/docs/pdf/Kaufman-2005-AAA.pdf

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FAMILY DAUBENTONIDAE GRAY, 1863
Daubentonia robusta (Lamberton, 1934).
Mem. Acad. Malgache 17: 40
TYPE LOCALITY: Sirave (Madagascar).
DISTRIBUTION: Madagascar.
FAMILY XENOTRICHIDAE HERSHKOVITZ 1970

www.google.co.uk/search?q=Pachylemur+insignis&hl=en&lr=&start=40&sa=N

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Further information and bones compared to the living species:
www.laits.utexas.edu/shapiro/sub/sub05.html
www.laits.utexas.edu/shapiro/sub/sub08.html

[sordes]

I calculated, based on the size difference of the known bones and the more robust constitution a weight which was about 3,0-3,2 times of the living Aye aye, which weighs about 2,4-2,8kg ing general, but with some specimens up to 4kg. So Daubentonia robusta was at minimum about 8kg in average, with some specimens probably reaching weights of nearly 13kg.

[another specialist]

sordes said:

Further information and bones compared to the living species:
www.laits.utexas.edu/shapiro/sub/sub05.html
www.laits.utexas.edu/shapiro/sub/sub08.html

Daubentonia robusta

The giant aye-aye was morphologically similar to the extant species but five times larger in size. Because of its large size, it was a deliberate arboreal quadruped. The incisal and manual morphology of D. robusta suggest that it exploited “structurally defended” resources in the same manner as the extant aye-aye.

Geographical Distribution: southwestern to central Madagascar
Age: Late Quaternary
Dental Formula: 1.0.1.3 / 1.0.0.3
Reconstructed Body Mass: 13 kg
Diet: primarily nuts, also seeds, fruit, insects, other fauna

Daubentonia - Cranial Characteristics

There are no cranial remains currently known for D. robusta.

Daubentonia - Dental Characteristics

D. robusta possesses nearly identical dental morphology to that of other aye-ayes but is just larger in size.






Daubentonia - Postcranial Characteristics

The subfossil species of Daubentonia resembles that of the extant species, except it is larger in size and more robust. Like the extant D. madagascariensis, D. robusta has an enormous brachialis flange. Its forelimb is short and robust relative to the hindlimb. It also has a relatively small femoral head and narrow and rod-like iliac blades.

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www.scribd.com/doc/2621714/Mysterious-CreaturesA-Guide-To-Cryptozoology

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The macroevolutionary impact of recent and imminent mammal extinctions on Madagascar.

Many of Madagascar’s unique species are threatened with extinction. However, the severity of recent and potential extinctions in a global evolutionary context is unquantified. Here, we compile a phylogenetic dataset for the complete non-marine mammalian biota of Madagascar and estimate natural rates of extinction, colonization, and speciation. We measure how long it would take to restore Madagascar’s mammalian biodiversity under these rates, the “evolutionary return time” (ERT). At the time of human arrival there were approximately 250 species of mammals on Madagascar, resulting from 33 colonisation events (28 by bats), but at least 30 of these species have gone extinct since then. We show that the loss of currently threatened species would have a much deeper long-term impact than all the extinctions since human arrival. A return from current to pre-human diversity would take 1.6 million years (Myr) for bats, and 2.9 Myr for non-volant mammals. However, if species currently classified as threatened go extinct, the ERT rises to 2.9 Myr for bats and 23 Myr for non-volant mammals. Our results suggest that an extinction wave with deep evolutionary impact is imminent on Madagascar unless immediate conservation actions are taken.

www.nature.com/articles/s41467-022-35215-3

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Who Ate the Subfossil Lemurs? A Taphonomic and Community Study of Raptor, Crocodylian and Carnivoran Predation of the Extinct Quaternary Lemurs of Madagascar.

protectedareas.mg/document/show/269191