Discovery of new giant subfossil lemurs in the Ankarana Mountains of Northern Madagascar

Simons, Elwyn L.; Godfrey, Laurie R.; Vuillaume-Randriamanantena, M.; Chatrath, Prithijit S.; Gagnon, Mario

doi:10.1016/0047-2484(90)90072-j

Cited by 28 publications

(12 citation statements)

References 5 publications

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“…This latter form is the largest of the madagascariensislgrandidieri group as indicated by the lengths of the skull (280.6 mm; one other intact skull is a subadult measuring 253.0 mm), femur (193.3 mm; n = 3), and humerus (212.4 mm; n=3) for specimens from Ampasambazimba. Subfossil specimens were recently discovered in the Ankarana mountains in the North but information is too preliminary to make any determination of relative size [Simons et al, 1990; Vuillaume-Randriamanantena & Godfrey, in press].…”

Section: Megaladapismentioning

confidence: 99%

Ecogeographic size variation among the living and subfossil prosimians of Madagascar

Albrecht

Jenkins

Godfrey

1990

American J Primatol

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115

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The living Malagasy prosimians and their recently extinct subfossil relatives include about 20 genera and 8 families that can be considered one contemporaneous fauna. They exhibit morphological, behavioral, and ecological differences comparable to living anthropoid primates. This diversity is matched by the equally varied topography, climate, and vegetation of Madagascar. To investigate habitat-related size variation, skull lengths of wild-caught adults were used to compare sizes of closely-related conspecific and congeneric "sister taxa." More than 1,550 museum specimens were examined representing virtually all known forms of extant and subfossil Malagasy prosimians. A total of 98 pairwise, sister-taxa comparisons among 76 different taxa from six broadly defined ecogeographic regions revealed a consistent pattern of size variation: 1) the smallest Malagasy prosimians inhabit the semiarid forests, bush, and thickets of the South; 2) next largest are those from the dry deciduous forests of the West and the humid but seasonal forests of the Sambirano; 3) larger yet are those from humid tropical and secondary forests of the East; and 4) the largest of all are the extinct forms of the central highlands that lived in what was probably a savanna-bush-woodland mosaic in the past but is now grasslands devoid of living prosimians. Taxa from the extreme North are more variable in size (small, intermediate, or large), which may reflect the mixture of local habitats in northern Madagascar. The ecogeographic size differences may be adaptive responses related to the carrying capacity of local environments such that smaller-sized species are favored where the resources they exploit are more limited. Field observations on behavioral thermoregulation, home range size, and population densities offer some support for this hypothesis. Ecologically induced size differences among local populations were probably one factor in speciation events leading to the modern diversity of the Malagasy primates.

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Section: Megaladapismentioning

confidence: 99%

Ecogeographic size variation among the living and subfossil prosimians of Madagascar

Albrecht

Jenkins

Godfrey

1990

American J Primatol

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115

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“…At the same time, subfossil evidence from southwestern Madagascar of a large extinct raptor species (genus Aquila [32]) notwithstanding, there is today no shortage of potential lemur predators at Ambato [18,33]. Evolutionary disequilibrium [31] and competitive release [17], in the form of the spasm of recent extinctions on Madagascar that eliminated a host of large-bodied Lemuriformes [24,31,[34][35][36], may have allowed extant lemurs to expand their activity patterns from being crepuscular or nocturnal and adopt diurnal activity, thereby becoming cathemeral. However, the extent to which this removal of potential competitors affected the lemuroid community of the Sambirano, if at all, remains unclear [24].…”

Section: Discussionmentioning

confidence: 99%

“…However, the extent to which this removal of potential competitors affected the lemuroid community of the Sambirano, if at all, remains unclear [24]. The subfossil lemurs excavated in the caves of the Ankarana Massif [36], approximately 120 km north of Ambato, cannot be assumed to be representative of the Sambirano lemuroid community prior to the extinction spasm -without question, the extant lemur communities at these two sites differ considerably [18,36]. In light of this apparent lack of the hypothesized requisite combination of predisposing factors [17], the cathemeral activity of E. macaco macaco may best be understood in terms of being an activity pattern that is perhaps the ancestral condition for the genus as a whole, as suggested by Tattersall [24].…”

Section: Discussionmentioning

confidence: 99%

Cathemeral Behavior of Eulemur macaco macaco at Ambato Massif, Madagascar

Colquhoun¹

1998

IJFP

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A 15-month field study of Eulemur macaco macaco socioecology at Ambato Massif revealed year-round cathemeral activity. There were both daily and seasonal rhythms of diurnal behavior. However, as measured by vocalizations and group movements, the relative occurrence of nocturnal activity was not markedly seasonal and apparently followed the phases of the moon. Increased nocturnal activity was noted when the moon was waxing and during the full moon. These nocturnal activity data are preliminary, as they were gathered by indirect methods. Nonetheless, these data strongly suggest that black lemurs do not exhibit a seasonal increase in cathemeral activity in association with the scarcity of fruit resources during the austral winter and a concomitant need to increase consumption of leaves, flowers or nectar.

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“…Extinct Malagasy strepsirrhines exhibited considerable diversity in body size as well as postural and locomotor adaptations (Walker, 1974;Tattersall, 1982;Jungers, 1977Jungers, , 1980Godfrey, 1988;Godfrey et al, 1990Godfrey et al, , 1995Godfrey et al, , 1997aRandria, 1990;Simons et al, 1990Simons et al, , 1992Jungers et al, 1991Jungers et al, , 2002Wunderlich et al, 1996;Hamrick et al, 2000;Godfrey and Jungers, 2002). None of the extinct lemurs is believed to have engaged in leaping (as is common among extant Malagasy strepsirrhines), and some of the locomotor activities inferred for them, such as slothlike suspensory behaviors, are unrepresented among living lemurs.…”

mentioning

confidence: 94%

Morphometric analysis of lumbar vertebrae in extinct Malagasy strepsirrhines

Shapiro

Seiffert

Godfrey

et al. 2005

American J Phys Anthropol

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Previous research on subfossil lemurs has revealed much about the positional behavior of these extinct strepsirrhines, but a thorough quantitative analysis of their vertebral form and function has not been performed. In this study, 156 lumbar vertebrae of Pachylemur, Archaeolemur, Megaladapis, Mesopropithecus, Babakotia, and Palaeopropithecus (11 species in all) were compared to those of 26 species of extant strepsirrhines and haplorhines. Lumbar shape was compared among species, using a principal components analysis (PCA) in conjunction with selected vertebral indices. The first principal component revealed strong separation between Palaeopropithecus at one extreme, and Archaeolemur/Pachylemur at the other, with Babakotia, Mesopropithecus, and Megaladapis in an intermediate position. Palaeopropithecus has markedly shorter spinous processes and wider laminae than do the other subfossil taxa, consistent with sloth-like, inverted suspensory postures. The moderately reduced lumbar spinous processes of Babakotia, Mesopropithecus, and Megaladapis are convergent with those of lorisids and Pongo, reflecting antipronogrady, but a less specialized adaptation than that of Palaeopropithecus. Archaeolemur and Pachylemur share relatively elongated spinous processes, in conjunction with other features (e.g., transverse process orientation and relatively short vertebral bodies) indicative of pronograde, quadrupedal locomotion characterized by reduced agility. All subfossil taxa exhibit adaptations emphasizing lumbar spinal stability (e.g., relatively short vertebral bodies, and transverse processes that are not oriented ventrally); we believe this probably reflects convergent mechanical demands connected to large body size, irrespective of specific locomotor mode. Reconstructions of positional behavior in subfossil lemurs based on lumbar vertebrae are largely consistent with those based on other aspects of the postcrania.

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Discovery of new giant subfossil lemurs in the Ankarana Mountains of Northern Madagascar

Cited by 28 publications

References 5 publications

Ecogeographic size variation among the living and subfossil prosimians of Madagascar

Ecogeographic size variation among the living and subfossil prosimians of Madagascar

Cathemeral Behavior of Eulemur macaco macaco at Ambato Massif, Madagascar

Morphometric analysis of lumbar vertebrae in extinct Malagasy strepsirrhines

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