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1. SUBFOSSIL BIRDS AT VINTANY CAVE: A KEY TO UNDERSTANDING THE PAST ECOLOGY AND RECENT HISTORY OF TSIMANAMPESOTSE NATIONAL PARK

   Rasolonjatovo, HA M; Goodman, S M; Ranivoharimanana, L; Godfrey, L; Muldoon, KM (March 2024, NA)

   NA (Ed.)

   Madagascar, an island renowned for its rich biodiversity, is home to an impressive variety of bird species. The island’s Quaternary subfossil sites have yielded the remains of birds that bear testimony to an even richer avifauna during the recent past (Figure 1). These species are also excellent indicators of past habitats, due to habitat-specific adaptations (Behrensmeyer et al., 2003; Carrera et al., 2021). We studied the subfossil avifauna from Vintany Cave at Tsimanampesotse, SW Madagascar, to reconstruct the habitats of this region prior to human population expansion. The bird fossils were found in deposits alongside remains of other vertebrate species including large-bodied frugivorous lemurs, browsing elephant birds, and carnivorans such as Fossa fossana and Cryptoprocta spelea, the latter an extinct euplerid that preyed on large- bodied lemurs such as Pachylemur and Megaladapis. Radiocarbon dates establish an age range between 2000 and 3000 yr BP. 

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2. Teasing Apart Impacts of Human Activity and Regional Drought on Madagascar’s Large Vertebrate Fauna: Insights From New Excavations at Tsimanampesotse and Antsirafaly

   https://doi.org/10.3389/fevo.2021.742203  

   Godfrey, Laurie R.; Crowley, Brooke E.; Muldoon, Kathleen M.; Burns, Stephen J.; Scroxton, Nick; Klukkert, Zachary S.; Ranivoharimanana, Lovasoa; Alumbaugh, Jamie; Borths, Matthew; Dart, Ryan; et al (September 2021, Frontiers in Ecology and Evolution)

   Madagascar experienced a major faunal turnover near the end of the first millenium CE that particularly affected terrestrial, large-bodied vertebrate species. Teasing apart the relative impacts of people and climate on this event requires a focus on regional records with good chronological control. These records may document coeval changes in rainfall, faunal composition, and human activities. Here we present new paleontological and paleoclimatological data from southwestern Madagascar, the driest part of the island today. We collected over 1500 subfossil bones from deposits at a coastal site called Antsirafaly and from both flooded and dry cave deposits at Tsimanampesotse National Park. We built a chronology of Late Holocene changes in faunal assemblages based on 65 radiocarbon-dated specimens and subfossil associations. We collected stalagmites primarily within Tsimanampesotse but also at two additional locations in southern Madagascar. These provided information regarding hydroclimate variability over the past 120,000 years. Prior research has supported a primary role for drought (rather than humans) in triggering faunal turnover at Tsimanampesotse. This is based on evidence of: (1) a large freshwater ecosystem west of what is now the hypersaline Lake Tsimanampesotse, which supported freshwater mollusks and waterfowl (including animals that could not survive on resources offered by the hypersaline lake today); (2) abundant now-extinct terrestrial vertebrates; (3) regional decline or disappearance of certain tree species; and (4) scant local human presence. Our new data allow us to document the hydroclimate of the subarid southwest during the Holocene, as well as shifts in faunal composition (including local extirpations, large-vertebrate population collapse, and the appearance of introduced species). These records affirm that climate alone cannot have produced the observed vertebrate turnover in the southwest. Human activity, including the introduction of cattle, as well as associated changes in habitat exploitation, also played an important role. 

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3. Subfossil lemur discoveries from the Beanka Protected Area in western Madagascar

   https://doi.org/10.1017/qua.2019.54  

   Burney, David A.; Andriamialison, Haingoson; Andrianaivoarivelo, Radosoa A.; Bourne, Steven; Crowley, Brooke E.; de Boer, Erik J.; Godfrey, Laurie R.; Goodman, Steven M.; Griffiths, Christine; Griffiths, Owen; et al (January 2020, Quaternary Research)

   A new fossil site in a previously unexplored part of western Madagascar (the Beanka Protected Area) has yielded remains of many recently extinct vertebrates, including giant lemurs (Babakotia radofilai, Palaeopropithecus kelyus, Pachylemur sp., and Archaeolemur edwardsi), carnivores (Cryptoprocta spelea), the aardvark-like Plesiorycteropus sp., and giant ground cuckoos (Coua). Many of these represent considerable range extensions. Extant species that were extirpated from the region (e.g., Prolemur simus) are also present. Calibrated radiocarbon ages for 10 bones from extinct primates span the last three millennia. The largely undisturbed taphonomy of bone deposits supports the interpretation that many specimens fell in from a rock ledge above the entrance. Some primates and other mammals may have been prey items of avian predators, but human predation is also evident. Strontium isotope ratios (87Sr/86Sr) suggest that fossils were local to the area. Pottery sherds and bones of extinct and extant vertebrates with cut and chop marks indicate human activity in previous centuries. Scarcity of charcoal and human artifacts suggests only occasional visitation to the site by humans. The fossil assemblage from this site is unusual in that, while it contains many sloth lemurs, it lacks ratites, hippopotami, and crocodiles typical of nearly all other Holocene subfossil sites on Madagascar. 

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4. Description of the subfossil crocodylians from a new Late Pleistocene subfossil site (Tsaramody, Sambaina Basin) in central Madagascar

   Rakotozandry, R.; Ranivoharimanana, L.; Ranaivosoa, V.; Rasolofomanana, N.; Hekkala, E.; Samonds, K.E. (December 2021, Malagasy nature)

   Madagascar is famous today not only for its unique biodiversity, but also for the high levels of endemism of plants and animals. Less appreciated is the fact that, in the recent past, the island had even greater biodiversity with many other endemic animals such as giant lemurs, elephant birds, pygmy hippopotami, tortoises, and crocodiles that have gone extinct within the past 2000 years. The extinction of many of these groups is thought to be the result of both human activities and environmental change. Most research has focused on the lemurs, hippopotami, and elephant birds. Other recently extinct animals, including the Malagasy horned crocodile (Voay robustus), are relatively poorly known. Madagascar’s subfossil crocodylians include two taxa: the extinct V. robustus (the Malagasy horned crocodile) and the extant Crocodylus niloticus. The latter arrived on Madagascar relatively recently and we know little about the habitat preferences, distributions and ecological interactions (if any) of either species during the Holocene. In order to better understand the recent history of crocodylian extinction in Madagascar, we must first identify which species were present and where they were found. We present here a description of subfossil crocodylian material collected from the newly discovered subfossil site of Tsaramody (Sambaina Basin), a high-elevation wetlandenvironment. At 1655 m, it represents the highest elevation subfossil site on the island. Here we describe both cranial (e.g., premaxillary, jugal, and squamosal “horns”) and postcranial elements (e.g., osteoderms). Our research indicates that crocodile material from Tsaramody appears morphologically to belong to V. robustus, the extinct species. However, oval tuberosities on the frontal bone and a triangular extension of the squamosal bone suggest previously unrecognized variation. 

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5. The growth and development of Pachylemur, a large-bodied lemurid,

   Rahantaharivao, N.J.; Godfrey, L.R.; Schwartz, G.T.; King, S.; Ranivoharimanana, L. (December 2021, Malagasy nature)

   As the largest-bodied member of the family Lemuridae and the presumed primary disperser of large seeds, Pachylemur, now extinct, was a critical member of Madagascar’s primate communities. Material of this genus has been found at almost all subfossil sites across Madagascar, but extensive samples of this taxon are known from very few. It has been one of the more historically neglected of the “giant” extinct lemurs, as it is not very different in morphology from its nearest extant relative, Varecia, except in body size. The flooded cave called Vintany at the Tsimanampesotse National Park in southwestern Madagascar has yielded numerous specimens of P. insignis, including whole skulls and mandibles, many isolated postcranial elements, and, importantly, partial associated skeletons of immature individuals. This material allows us to address previously unanswered questions regarding its paleobiology, including questions concerning its growth and development. This article focuses specifically on its life history profile (especially developmental sequences and life history-related traits such as Retzius line periodicity of the teeth and endocranial volume in adults). We ask to what extent, despite its larger size, did Pachylemur “grow” like its smaller-bodied relatives? Did its dental eruption sequence and index of Relative Retardation of the Replacement teeth resemble those of its closest relatives? Did it, like other lemurs, have a Retzius line periodicity that is lower than “expected” for a primate of its body size, and if so, what is the likely significance of this? Was its brain smaller than expected for a primate of its body size? For these and other questions, we evaluate how large-bodied lemurs differ from anthropoids of comparable body size. 

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