Babakotia

Last updated

Babakotia
Temporal range: Pleistocene–Northgrippian(Possible Late Miocene species)
O
S
D
C
P
T
J
K
Pg
N
Babakotia skull 001.jpg
Babakotia radofilai skull
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Strepsirrhini
Family: Palaeopropithecidae
Genus: Babakotia
Godfrey et al., 1990 [1]
Species:
B. radofilai
Binomial name
Babakotia radofilai
Godfrey et al., 1990 [2]
Babakotia range map.svg
Subfossil sites for
Babakotia radofilai [3]

Babakotia is an extinct genus of medium-sized lemur, or strepsirrhine primate, from Madagascar that contains a single species, Babakotia radofilai. Together with Palaeopropithecus , Archaeoindris , and Mesopropithecus , it forms the family Palaeopropithecidae, commonly known as the sloth lemurs. The name Babakotia comes from the Malagasy name for the indri, babakoto, to which it and all other sloth lemurs are closely related. Due to its mix of morphological traits that show intermediate stages between the slow-moving smaller sloth lemurs and the suspensory large sloth lemurs, it has helped determine the relationship between both groups and the closely related and extinct monkey lemurs.

Contents

Babakotia radofilai and all other sloth lemurs share many traits with living sloths, demonstrating convergent evolution. It had long forearms, curved digits, and highly mobile hip and ankle joints. Its skull was more heavily built than that of indriids, but not as much as in the larger sloth lemurs. Its dentition is similar to that of all other indriids and sloth lemurs. It lived in the northern part of Madagascar and shared its range with at least two other sloth lemur species, Palaeopropithecus ingens and Mesopropithecus dolichobrachion. Babakotia radofilai was primarily a leaf-eater (folivore), though it also ate fruit and hard seeds. It is known only from subfossil remains and may have died out shortly after the arrival of humans on the island, but not enough radiocarbon dating has been done with this species to know for certain.

Etymology

The name of the genus Babakotia derives from the Malagasy common name for the Indri, babakoto, a close relative of Babakotia. The species name, radofilai, was chosen in honor of French mathematician and expatriate Jean Radofilao, an avid spelunker who mapped the caves where remains of Babakotia radofilai were first found. [4]

Classification and phylogeny

Restoration of Babakotia radofilai Babakotia radofilai.jpg
Restoration of Babakotia radofilai

Babakotia radofilai is the sole member of the genus Babakotia and belongs to the family Palaeopropithecidae, which includes three other genera of sloth lemurs: Palaeopropithecus , Archaeoindris , and Mesopropithecus . This family in turn belongs to the infraorder Lemuriformes, which includes all the Malagasy lemurs. [5] [2]

The first subfossil remains of Babakotia radofilai were discovered as part of a series of expeditions following upon discoveries of Jean Radofilao and two Anglo-Malagasy reconnaissance expeditions in 1981 and 1986–7. [6] [7] The second wave of research was launched in the 1980s by biological anthropologist Elwyn L. Simons [8] who unearthed in 1988 at a cave known as Antsiroandoha in the Ankarana Massif, northern Madagascar a nearly complete skeleton and skull in addition to the remains of roughly a dozen other individuals. [3] Identified immediately as a sloth lemur (palaeopropithecid) upon its discovery, [4] Babakotia along with Mesopropithecus helped to settle a debate about the relationship between the sloth lemurs, the monkey lemurs (family Archaeolemuridae) and the living indriids. The monkey lemurs had skulls that more closely resembled the indriids, but their teeth were very specialized and unlike those of the indriids. The larger sloth lemurs, on the other hand, retained a dentition similar to living indriids, yet differed by having more robust and specialized skulls. Babakotia and Mesopropithecus not only shared the indriid dentition, but also the indriid-like skulls, providing evidence that sloth lemurs were most closely related to living indriids, with monkey lemurs as a sister group to both. [9] Furthermore, the discovery of Babakotia helped to demonstrate that the ancestral indriids were not "ricochetal leapers" (bouncing rapidly from tree to tree) like living indriids, but vertical climbers and hanging feeders, and possibly occasional leapers. [10]

Anatomy and physiology

Weighing between 16 and 20 kg (35 and 44 lb), Babakotia radofilai was a medium-sized lemur and noticeably smaller than the large sloth lemurs (Archaeoindris and Palaeopropithecus), but larger than the small sloth lemurs (Mesopropithecus). [5] [2] In many ways, it had an intermediate level of adaptations for suspensory behavior between the large sloth lemurs and the small sloth lemurs. [2] [3] [11] [9] [12] This includes its highly mobile hip and ankle joints, as well as other specializations in the vertebral column, pelvis, and limbs. [12] Its forelimbs were 20% longer than its hind limbs, giving it a higher intermembral index (~119) than Mesopropithecus (~97 to 113), suggesting that it was convergently similar to arboreal sloths. [12] [13] It had a reduced tarsus and curved, elongated digits, adapted for grasping and suggesting suspensory behavior. [12] [14] Its hind feet were reduced, making it well-adapted for climbing and hanging (like in other palaeopropithecids), but not leaping (like in indriids). [5] [2] [3] Wrist bones found in 1999 further demonstrated that this species was a vertical climber. [15] Additionally, analysis of its semicircular canals, [16] lumbar vertebrae and its spinous processes indicate slow movement and climbing (antipronograde) adaptations, but not necessarily sloth-like hanging, vertical clinging, or leaping. [17] Therefore, it was likely a slow climber like a loris and also exhibited some suspensory behavior like a sloth. [8]

Babakotia placement within the lemur phylogeny [18] [19] [11]
Lemuriformes

All sloth lemurs have relatively robust skulls compared to the indriids, [2] yet despite shared cranial features with the larger sloth lemurs, [9] its skull still resembles that of an indri. [5] The cranial traits shared with the other sloth lemurs include relatively small orbits, robust zygomatic arches, and a mostly rectangular hard palate. [2] The small orbits taken into consideration with the relative size of the optic canal suggest that Babakotia had low visual acuity, which is typical for lemurs. [20] The skull length averages 144 mm (5.7 in). [3]

The dental formula of Babakotia radofilai was the same as the other sloth lemurs and indriids: either 2.1.2.31.1.2.3 [2] [9] or 2.1.2.32.0.2.3 × 2 = 30. [3] It is unclear whether one of the teeth in the permanent dentition is an incisor or canine, resulting in these two conflicting dental formulae. [21] Regardless, the lack of either a lower canine or incisor results in a four-tooth toothcomb instead of the more typical six-tooth strepsirrhine toothcomb. Babakotia radofilai differed slightly from indriids in having somewhat elongated premolars. Its cheek teeth had broad shearing crests and crenulated enamel. [3]

Distribution and ecology

Like all other lemurs, Babakotia radofilai was endemic to Madagascar. Its remains have only been found in limestone caves at the Ankarana Massif within the Ankarana Reserve and at Anjohibe, indicating a range across the extreme north and northwest of the island. [2] [3] [22] The restricted range of this arboreal primate, particularly during a time when much of the island was blanketed in forest, might have been due to habitat specificity, competitive exclusion, or some other unknown factor. [23] It was sympatric (occurred together) with Palaeopropithecus maximus and Mesopropithecus dolichobrachion. [8] [24] [25]

Based on its size, the morphology of its molars, and microwear analysis on its teeth, Babakotia radofilai was likely a folivore, while supplementing its diet with fruit and hard seeds. [5] [11] [20] [26] In all sloth lemurs, including Babakotia radofilai, the permanent teeth erupted early, a trait seen in indriids that improves survivability of juveniles during the first dry season following weaning. [12]

Extinction

Because it died out relatively recently and is only known from subfossil remains, it is considered to be a modern form of Malagasy lemur. [22] Babakotia radofilai lived during the Holocene epoch and is thought to have disappeared shortly after the arrival of humans to the island, possibly within the last 1,000 years. [2] The only radiocarbon date that has been reported for it dates back to 31002800 BCE. [27]

Related Research Articles

<span class="mw-page-title-main">Lemur</span> Clade of primates endemic to the island of Madagascar

Lemurs are wet-nosed primates of the superfamily Lemuroidea, divided into 8 families and consisting of 15 genera and around 100 existing species. They are endemic to the island of Madagascar. Most existing lemurs are small, have a pointed snout, large eyes, and a long tail. They chiefly live in trees and are active at night.

<i>Megaladapis</i> Extinct genus of lemurs

Megaladapis, informally known as the koala lemur, is an extinct genus of lemurs belonging to the family Megaladapidae, consisting of three species that once inhabited the island of Madagascar. The largest measured between 1.3 to 1.5 m in length.

<i>Archaeoindris</i> Extinct giant lemur

Archaeoindris fontoynontii is an extinct giant lemur and the largest primate known to have evolved on Madagascar, comparable in size to a male gorilla. It belonged to a family of extinct lemurs known as "sloth lemurs" (Palaeopropithecidae) and, because of its extremely large size, it has been compared to the ground sloths that once roamed North and South America. It was most closely related to Palaeopropithecus, the second largest type of sloth lemur. Along with the other sloth lemurs, Archaeoindris was related to the living indri, sifakas, and woolly lemurs, as well as the recently extinct monkey lemurs (Archaeolemuridae). The genus, Archaeoindris, translates to "ancient indri-like lemur", even though it probably became extinct recently, around 350 BCE.

<span class="mw-page-title-main">Ankarana Special Reserve</span> Protected area in northern Madagascar

Ankarana Special Reserve is a protected area in northern Madagascar created in 1956. It is a small, partially vegetated plateau composed of 150-million-year-old middle Jurassic limestone. With an average annual rainfall of about 2,000 millimetres (79 in), the underlying rocks have been eroded to produce caves and feed subterranean rivers—a karst topography. The rugged relief and the dense vegetation have helped protect the region from human intrusion and exploitation.

<i>Palaeopropithecus</i> Extinct genus of lemurs

Palaeopropithecus is a recently extinct genus of large sloth lemurs from Madagascar related to living lemur species found there today. Three species are known, Palaeopropithecus ingens, P. maximus, and P. kelyus. Radiocarbon dates indicate that they may have survived until around 1300–1620 CE. Malagasy legends of the tretretretre or tratratratra are thought to refer to P. ingens.

<span class="mw-page-title-main">Fauna of Madagascar</span> Native animals of Madagascar

The fauna of Madagascar is a part of the wildlife of Madagascar.

<span class="mw-page-title-main">Monkey lemur</span> Extinct family of lemurs

The monkey lemurs or baboon lemurs (Archaeolemuridae) are a recently extinct family of lemurs known from skeletal remains from sites on Madagascar dated to 1000 to 3000 years ago.

<span class="mw-page-title-main">Sloth lemur</span> Extinct family of lemurs

The sloth lemurs (Palaeopropithecidae) comprise an extinct family of lemurs that includes four genera. The common name can be misleading, as members of Palaeopropithecidae were not closely related to sloths. This clade has been dubbed the ‘‘sloth lemurs’’ because of remarkable postcranial convergences with South American sloths. Despite postcranial similarities, the hands and feet show significant differences. Sloths possess long, curved claws, while sloth lemurs have short, flat nails on their distal phalanges like most primates.

<i>Archaeolemur</i> Extinct genus of lemurs

Archaeolemur is an extinct genus of subfossil lemurs known from the Quaternary of Madagascar. Archaeolemur is one of the most common and well-known of the extinct giant lemurs as hundreds of its bones have been discovered in fossil deposits across the island. It was larger than any extant lemur, with a body mass of approximately 18.2–26.5 kg (40–58 lb), and is commonly reconstructed as the most frugivorous and terrestrial of the fossil Malagasy primates. Colloquially known as a "monkey lemur," Archaeolemur has often been compared with anthropoids, specifically the cercopithecines, due to various morphological convergences. In fact, it was even misidentified as a monkey when remains were first discovered. Following human arrival to Madagascar just over 2000 years ago, many of the island’s megafauna went extinct, including the giant lemurs. Radiocarbon dating indicates that Archaeolemur survived on Madagascar until at least 1040-1290 AD, outliving most other subfossil lemurs.

<i>Pachylemur</i> Extinct genus of lemurs

Pachylemur is an extinct, giant lemur most closely related to the ruffed lemurs of genus Varecia. Two species are known, Pachylemur insignis and Pachylemur jullyi, although there is some doubt as to whether or not they may actually be the same species. Pachylemur is sometimes referred to as the giant ruffed lemur, because although it and the living ruffed lemurs had similar teeth and skeletons, Pachylemur was more robust and as much as three to four times larger. DNA studies have confirmed a sister group relationship between these two types of lemur. Like living ruffed lemurs, Pachylemur specialized in eating fruit, and was therefore an important seed disperser, possibly for tree species with seeds too large for even ruffed lemurs to swallow. In the spiny thickets of southwestern Madagascar, they were also likely to have dispersed seeds evolved to attach to fur and be carried away. Unlike ruffed lemurs, the fore- and hindlimbs of Pachylemur were nearly the same length, and therefore it was likely to be a slow, deliberate climber. However, both used hindlimb suspension to reach fruit on small branches below them.

<i>Hadropithecus</i> Extinct genus of lemurs

Hadropithecus is a medium-sized, extinct genus of lemur, or strepsirrhine primate, from Madagascar that includes a single species, Hadropithecus stenognathus. Due to its rarity and lack of sufficient skeletal remains, it is one of the least understood of the extinct lemurs. Both it and Archaeolemur are collectively known as "monkey lemurs" or "baboon lemurs" due to body plans and dentition that suggest a terrestrial lifestyle and a diet similar to that of modern baboons. Hadropithecus had extended molars and a short, powerful jaw, suggesting that it was both a grazer and a seed predator.

<i>Mesopropithecus</i> Extinct genus of small to medium-sized lemur from Madagascar

Mesopropithecus is an extinct genus of small to medium-sized lemur, or strepsirrhine primate, from Madagascar that includes three species, M. dolichobrachion, M. globiceps, and M. pithecoides. Together with Palaeopropithecus, Archaeoindris, and Babakotia, it is part of the sloth lemur family (Palaeopropithecidae). Once thought to be an indriid because its skull is similar to that of living sifakas, a recently discovered postcranial skeleton shows Mesopropithecus had longer forelimbs than hindlimbs—a distinctive trait shared by sloth lemurs but not by indriids. However, as it had the shortest forelimbs of all sloth lemurs, it is thought that Mesopropithecus was more quadrupedal and did not use suspension as much as the other sloth lemurs.

<span class="mw-page-title-main">Subfossil lemur</span> Lemurs from Madagascar that are represented by recent (subfossil) remains

Subfossil lemurs are lemurs from Madagascar that are represented by recent (subfossil) remains dating from nearly 26,000 years ago to approximately 560 years ago. They include both extant and extinct species, although the term more frequently refers to the extinct giant lemurs. The diversity of subfossil lemur communities was greater than that of present-day lemur communities, ranging to as high as 20 or more species per location, compared with 10 to 12 species today. Extinct species are estimated to have ranged in size from slightly over 10 kg (22 lb) to roughly 160 kg (350 lb). Even the subfossil remains of living species are larger and more robust than the skeletal remains of modern specimens. The subfossil sites found around most of the island demonstrate that most giant lemurs had wide distributions and that ranges of living species have contracted significantly since the arrival of humans.

<span class="mw-page-title-main">Taxonomy of lemurs</span> Science of describing species and defining the evolutionary relationships between taxa of lemurs

Lemurs were first classified in 1758 by Carl Linnaeus, and the taxonomy remains controversial today, with approximately 70 to 100 species and subspecies recognized, depending on how the term "species" is defined. Having undergone their own independent evolution on Madagascar, lemurs have diversified to fill many ecological niches normally filled by other types of mammals. They include the smallest primates in the world, and once included some of the largest. Since the arrival of humans approximately 2,000 years ago, lemurs have become restricted to 10% of the island, or approximately 60,000 square kilometers (23,000 sq mi), and many face extinction. Concerns over lemur conservation have affected lemur taxonomy, since distinct species receive increased conservation attention compared to subspecies.

Charles Lamberton was a French paleontologist who lived and studied on the island of Madagascar between 1911 and 1948 and specialized in the recently extinct subfossil lemurs. He made significant contributions towards fixing misattributions of skeletal remains and poor interpretations of subfossil lemur behavior. His paleontological expeditions during the 1930s led to the discovery of a new species of Mesopropithecus, a type of sloth lemur. Three species—one mammal and two reptiles—were named after him, although one is now considered a taxonomic synonym.

<span class="mw-page-title-main">Berthe Rakotosamimanana</span> Malagasy primatologist and paleontologist

Berthe Rakotosamimanana was a primatologist and palaeontologist from Madagascar.

<span class="mw-page-title-main">Andrahomana Cave</span> Complex of sinkholes in south eastern Madagascar

The Andrahomana Cave is a complex of sinkholes in Andranobory in south eastern Madagascar.

Ampasambazimba is a mountain peak and subfossil site in Madagascar, near Analavory, (Itasy) most known for being the site of the remains of the extinct giant sloth lemur Archaeoindris.

References

  1. McKenna, M.C.; Bell, S.K. (1997). Classification of Mammals: Above the Species Level. Columbia University Press. p. 335. ISBN   978-0-231-11013-6.
  2. 1 2 3 4 5 6 7 8 9 10 Nowak, R.M. (1999). "Family Palaeopropithecidae: Sloth Lemurs" . Walker's Mammals of the World (6th ed.). Johns Hopkins University Press. pp.  89–91. ISBN   978-0-8018-5789-8.
  3. 1 2 3 4 5 6 7 8 Godfrey, L.R.; Jungers, W.L. (2002). "Chapter 7: Quaternary fossil lemurs". In Hartwig, W.C. (ed.). The Primate Fossil Record. Cambridge University Press. pp. 97–121. ISBN   978-0-521-66315-1.
  4. 1 2 Godfrey, L.R.; Simons, E.L.; Chatrath, P.J.; Rakotosamimanana, B. (1990). "A new fossil lemur (Babakotia, Primates) from northern Madagascar". Comptes Rendus de l'Académie des Sciences. 2. 81: 81–87.
  5. 1 2 3 4 5 Mittermeier, R.A.; Konstant, W.R.; Hawkins, F.; Louis, E.E.; Langrand, O.; Ratsimbazafy, J.; Rasoloarison, R.; Ganzhorn, J.U.; Rajaobelina, S.; Tattersall, I.; Meyers, D.M. (2006). "Chapter 3: The Extinct Lemurs". Lemurs of Madagascar. Illustrated by S.D. Nash (2nd ed.). Conservation International. pp. 37–51. ISBN   978-1-881173-88-5.
  6. Wilson, J.M.; Stewart, P.D.; Ramangason, G.-S.; Denning, A.M.; Hutchings, M.S. (1989). "Ecology and conservation of the crowned lemur at Ankarana, N. Madagascar with notes on Sanford's lemur, other sympatrics and subfossil lemurs". Folia Primatologica. 52 (1–2): 1–26. doi:10.1159/000156379. PMID   2807091.
  7. Wilson, J.M.; Godrey, L.R.; Simons, E.L.; Stewart, P.D.; Vuillaume-Randriamanantena, M. (1995). "Past and present lemur fauna at Ankarana, N. Madagascar" (PDF). Primate Conservation. 16: 47–52.
  8. 1 2 3 Godfrey, L.R.; Jungers, W.L. (2003). "The Extinct Sloth Lemurs of Madagascar" (PDF). Evolutionary Anthropology. 12 (6): 252–263. doi:10.1002/evan.10123. S2CID   4834725. Archived from the original (PDF) on 2011-07-17. Retrieved 2010-03-13.
  9. 1 2 3 4 Mittermeier, R. A.; Tattersall, I.; Konstant, W.R.; Meyers, D.M.; Mast, R.B. (1994). "Chapter 4: The Extinct Lemurs". Lemurs of Madagascar. Illustrated by S.D. Nash (1st ed.). Conservation International. pp. 33–48. ISBN   978-1-881173-08-3.
  10. Jungers, W.L.; Godfrey, L.R.; Simons, E.L.; Chatrath, P.S.; Rakotosamimanana, B. (1991). "Phylogenetic and functional affinities of Babakotia (Primates), a fossil lemur from northern Madagascar" (PDF). Proceedings of the National Academy of Sciences. 88 (20): 9082–9086. Bibcode:1991PNAS...88.9082J. doi: 10.1073/pnas.88.20.9082 . PMC   52656 . PMID   1924371.
  11. 1 2 3 Godfrey, L.R.; Jungers, W.L. (2003). "Subfossil Lemurs". In Goodman, S.M.; Benstead, J.P (eds.). The Natural History of Madagascar. University of Chicago Press. pp. 1247–1252. ISBN   978-0-226-30306-2.
  12. 1 2 3 4 5 Simons, E.L. (1997). "Chapter 6: Lemurs: Old and New". In Goodman, S.M.; Patterson, B.D (eds.). Natural Change and Human Impact in Madagascar. Smithsonian Institution Press. pp. 142–166. ISBN   978-1-56098-682-9.
  13. Godfrey, L.R.; Jungers, W.L.; Reed, K.E.; Simons, E.L.; Chatrath, P.S. (1997). "Chapter 8: Subfossil Lemurs". In Goodman, S.M.; Patterson, B.D (eds.). Natural Change and Human Impact in Madagascar. Smithsonian Institution Press. pp. 218–256. ISBN   978-1-56098-682-9.
  14. Jungers, W.L.; Godfrey, L.R.; Simons, E.L.; Chatrath, P.S. (1997). "Phalangeal curvature and positional behavior in extinct sloth lemurs (Primates, Palaeopropithecidae)" (PDF). Proceedings of the National Academy of Sciences. 94 (22): 11998–12001. Bibcode:1997PNAS...9411998J. doi: 10.1073/pnas.94.22.11998 . PMC   23681 . PMID   11038588.
  15. Hamrick, M.W.; Simons, E.L.; Jungers, W.L. (2000). "New wrist bones of the Malagasy giant subfossil lemurs". Journal of Human Evolution. 38 (5): 635–650. Bibcode:2000JHumE..38..635H. doi:10.1006/jhev.1999.0372. PMID   10799257.
  16. Walker, A.; Ryan, T.M.; Silcox, M.T.; Simons, E.L.; Spoor, F. (2008). "The Semicircular Canal System and Locomotion: The Case of Extinct Lemuroids and Lorisoids". Evolutionary Anthropology. 17 (3): 135–145. doi:10.1002/evan.20165. S2CID   83737480.
  17. Shapiro, L.J.; Seiffert, C.V.M.; Godfrey, L.R.; Jungers, W.L.; Simons, E.L.; Randria, G.F.N. (2005). "Morphometric Analysis of Lumbar Vertebrae in Extinct Malagasy Strepsirrhines". American Journal of Physical Anthropology. 128 (4): 823–839. doi:10.1002/ajpa.20122. PMID   16110476.
  18. Horvath, J.E.; Weisrock, D.W.; Embry, S.L.; Fiorentino, I.; Balhoff, J.P.; Kappeler, P.; Wray, G.A.; Willard, H.F.; Yoder, A.D. (2008). "Development and application of a phylogenomic toolkit: Resolving the evolutionary history of Madagascar's lemurs" (PDF). Genome Research. 18 (3): 489–499. doi:10.1101/gr.7265208. PMC   2259113 . PMID   18245770 . Retrieved 24 February 2010.
  19. Orlando, L.; Calvignac, S.; Schnebelen, C.; Douady, C.J.; Godfrey, L.R.; Hänni, C. (2008). "DNA from extinct giant lemurs links archaeolemurids to extant indriids". BMC Evolutionary Biology. 8 (1): 121. Bibcode:2008BMCEE...8..121O. doi: 10.1186/1471-2148-8-121 . PMC   2386821 . PMID   18442367.
  20. 1 2 Godfrey, L.R.; Jungers, W.L.; Schwartz, G.T. (2006). "Chapter 3: Ecology and Extinction of Madagascar's Subfossil Lemurs". In Gould, L.; Sauther, M.L (eds.). Lemurs: Ecology and Adaptation. Springer. pp. 41–64. ISBN   978-0-387-34585-7.
  21. Ankel-Simons, F. (2007). "Chapter 7: Teeth". Primate Anatomy (3rd ed.). Academic Press. pp. 224–283. ISBN   978-0-12-372576-9.
  22. 1 2 Sussman, R.W. (2003). "Chapter 4: The Nocturnal Lemuriformes". Primate Ecology and Social Structure. Pearson Custom Publishing. pp. 107–148. ISBN   978-0-536-74363-3.
  23. Burney, D.A.; James, H.F.; Grady, F.V.; Rafamantanantsoa, J.; Ramilisonina; Wright, H.T.; Cowart, J.B. (1997). "Environmental Change, Extinction and Human Activity: Evidence from Caves in NW Madagascar". Journal of Biogeography. 24 (6): 755–767. Bibcode:1997JBiog..24..755B. doi:10.1046/j.1365-2699.1997.00146.x. hdl: 2027.42/75139 . JSTOR   2846113. S2CID   7171105.
  24. Godfrey, L.R.; Wilson, Jane M.; Simons, E.L.; Stewart, Paul D.; Vuillaume-Randriamanantena, M. (1996). "Ankarana: a window on Madagascar's Past". Lemur News. 2: 16–17.
  25. Wilson, Jane M.; Godfrey, L.R.; Simons, E.L.; Stewart, Paul D.; Vuillaume-Randriamanantena, M. (1995). "Past and Present Lemur Fauna at Ankarana, N. Madagascar". Primate Conservation. 16: 47–52.
  26. Rafferty, K.L.; Teaford, M.F.; Jungers, W.L. (2002). "Molar microwear of subfossil lemurs: improving the resolution of dietary inferences". Journal of Human Evolution. 43 (5): 645–657. Bibcode:2002JHumE..43..645R. doi:10.1006/jhev.2002.0592. PMID   12457853.
  27. Simons, E.L.; Burney, D.A.; Chatrath, P.S.; Godfrey, L.R.; Jungers, W.L.; Rakotosamimanana, B. (1995). "AMS 14C Dates for Extinct Lemurs from Caves in the Ankarana Massif, Northern Madagascar". Quaternary Research. 43 (2): 249–254. Bibcode:1995QuRes..43..249S. doi:10.1006/qres.1995.1025. S2CID   129808875.