Megaladapis madagascariensis (Madagascar Koala Lemur)

[another specialist]

FAMILY MEGALADAPIDAE
FORSYTH-MAJOR, 1893
Megaladapis Forsyth-Major, 1894. Philos.
Trans. R. Soc. London B Biol. Sci. 185: 16

TYPE SPECIES: Megaladapis madagascariensis
Forsyth-Major, 1894.
SYNONYMS: Peloriadapis Grandidier, 1899,
Palaeolemur Lorenz, 1900, Mesoadapis Lorenz,
1900, Megalindris Standing, 1908.
Megaladapis edwardsi Grandidier, 1899.
Bull. Mus. Natl. Hist. Nat. (Paris) 5: 276
TYPE LOCALITY: Ambolisatra (Madagascar).
SYNONYMS: insignis, destructus, brachycephalus,
dubius, dolichocephalus, gallienii.
DISTRIBUTION: Southern and southwestern
Madagascar.
Megaladapis grandidieri Standing, 1903.
Bull. Acad. Malgache (anc. ser.) 2: 229
TYPE LOCALITY: Ampasambazimba (Madagascar).
DISTRIBUTION: Central highlands of Madagascar.
Megaladapis madagascariensis Forsyth-Major,
1894. Philos. Trans. R. Soc. London B
Biol. Sci. 185: 16
TYPE LOCALITY: Ambolisatra (Madagascar).
DISTRIBUTION: Southern and southwestern
Madagascar.

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

[Bhagatí]

from:
en.wikipedia.org/wiki/Megaladapis
en.wikipedia.org/wiki/Image:Megaladaspis_madagascariensis.jpg

[another specialist]

New pedal remains of Megaladapis and their functional significance
R. E. Wunderlich 1 *, E. L. Simons 2, W. L. Jungers 3
1Doctoral Program in Anthropological Sciences, State University of New York at Stony Brook, Stony Brook, New York 11794-4364
2Duke University Primate Center, Duke University, Durham, North Carolina 27705
3Department of Anatomical Sciences, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794-8081


*Correspondence to R. E. Wunderlich, Department of Anthropology, State University of New York, Stony Brook, NY 11794-4364

Funded by:
NSF; Grant Number: DBS-9207084

Keywords
Foot • Function • Megaladapis • Madagascar


Abstract
New remains of Megaladapis from the caves within the Ankarana Range of northern Madagascar and the cave site of Ankilitelo near Toliara in southwestern Madagascar add considerably to the present sample of pedal remains for this genus. Here we describe and analyze the new pedal material and discuss the function of the Megaladapis foot in terms of positional behavior and substrate use. The northern specimens belong to the M. madagascariensis/M. grandidieri group in terms of size and morphology, whereas the new southwestern fossils are assigned to M. madagascariensis. The new specimens demonstrate that the small and intermediate sized M. madagascariensis and M. grandidieri were very similar in anatomy and inferred locomotor function, findings that also support the prior suggestion that they belong to a single widespread subgenus (Megaladapis). The new fossils provide the first examples of many pedal elements and present the first opportunity to analyze the whole pedal complex from associated remains.
The foot of Megaladapis is distinctive among primates in numerous features. Intrinsic proportions of the hindlimb indicate that the foot is relatively longer than that of any other primate. The first complete calcanei reveal a large and highly modified hindfoot. The calcaneus is reduced distally, indicating an emphasis on climbing over leaping or quadrupedal walking and running. Proximally, a large, medially directed calcaneal tuberosity suggests both a strong inversion component to plantarflexion and a well-developed abductor mechanism and recalls the calcaneal morphology of the larger lorisines in some respects. Talar shape is consistent with considerable tibial rotation during plantarflexion and dorsiflexion. The subtalar joint is designed to emphasize supination/pronation and medial/lateral rotation over proximodistal translation. The distal tarsals are extremely reduced in length, and they form a high transverse arch and a serial tarsus; this configuration promotes inversion/eversion at the transverse tarsal joint. The phalanges are long and moderately curved, and the hallux is very long, robust, and abducted.
Pedal morphology suggests that Megaladapis (subgenus Megaladapis) was well adapted to exploit an arboreal environment. The grasping mechanism of Megaladapis is an extreme modification of the prosimian condition, emphasizing a highly inverted set, mobility in rotation, and a powerful abduction/flexion type grasp using large hallux and the lateral abductor musculature. Such a mechanism insures a secure grasp regardless of the position of the hindlimb or the substrate. These pedal design features contrast with the grasping strategy seen in highly arboreal palaeopropithecids (or sloth lemurs), a group that reduces and modifies the hindfoot, culminating in Palaeopropithecus, and emphasizes extrinsic digital flexors in a more hook-like mechanism. Much less is known of M. (Peloriadapis) edwardsi. The larger body size, more gorilla-like talar articular morphology, and anatomy of the proximal fifth metatarsal suggest that this species may have been more terrestrial than the smaller forms, but other aspects of pedal morphology suggest it also exploited arboreal habitats.

www3.interscience.wiley.com/cgi-bin/abstract/57826/ABSTRACT?CRETRY=1&SRETRY=0

[another specialist]

Walker's Mammals of the World
By Ronald M. Nowak, Ernest Pillsbury Walker

[another specialist]

Walker's Primates of the World
By Ronald M. Nowak, Ernest Pillsbury Walker, Russell A. Mittermeier, William R. Konstant, Anthony B. Rylands

[another specialist]

A great PDF file on this species can be found here

journals.royalsociety.org/content/j6373k341qw5256v/?p=ffded15d0f4c4956ba749d2de6127a9a&pi=43

[another specialist]

From the above PDF file

[simontonge]

This is a photo of a Megaladapis skull on view at Parc Tsimbazaza in Antananarivo many years ago. It is labelled M. edwardsi but that is now regarded as a synonym of M. madagascariensis.

Attachments:

[surroundx]

Original description:

Forsyth Major, C. I. (1894). On Megaladapis madagascariensis, an Extinct Gigantic Lemuroid from Madagascar; with Remarks on the Associated Fauna, and on Its Geological Age. Philosophical Transactions of the Royal Society of London. B 185: 15-38.

[Melanie]

The Functional Significance of Airorhynchy in Megaladapis
Tattersall, Ian

Author affiliations

Keywords: Megaladapis Malagasy subfossil lemur Craniofacial flexion Feeding adaptation
Folia Primatol 1972;18:20–26
doi.org/10.1159/000155466


In association with airorhynchy, or retro flexion of the facial skeleton on the cranial base, the skull of the extinct vertical-clinging Malagasy lemuroid Megaladapis possesses a backwardly-oriented foramen magnum.It is suggested that these two features form part of a functional complex which in effect turned the animal’s head into an extension of the neck, greatly increasing the radius within which dental cropping of food materials was possible from a single resting position.

www.karger.com/Article/Abstract/155466

[Sebbe]

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

[Sebbe]

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