Browsing by Author "Gunnell, Gregg F."
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Item Bats (Chiroptera) from Olduvai Gorge, early Pleistocene, Bed I (Tanzania). (American Museum novitates, no. 3846)(American Museum of Natural History., 2015-12-16) Gunnell, Gregg F.; Butler, P. M., 1912-2015.; Greenwood, Marjorie.; Simmons, Nancy B.Olduvai Gorge in Tanzania is most famous for producing some of the first discoveries of fossil hominins in East Africa. Zinjanthropus (= Paranthropus) boisei was initially discovered in 1959 from Olduvai Bed I. During screen-washing operations to search for more hominin material at Olduvai, an associated faunal assemblage was accumulated including 40 numbered specimens of fossil bats. Except for seven dental specimens, this collection consists entirely of postcrania, almost exclusively complete or fragmentary humeri representing both proximal and distal ends. Although briefly discussed in preliminary reports, these specimens have remained undescribed for over 50 years and have never been comprehensively compared to extant species. Our analyses indicate that the Olduvai bat fossils represent five families and nine genera, and include four new species: Myzopoda africana, n. sp., Cardioderma leakeyi, n. sp., Scotoecus olduvensis, n. sp., and Nycticeinops serengetiensis, n. sp. The Olduvai bat fossils come from the FLK North 1 and FLK NN1 levels, both of early Pleistocene age, and ranging between 1.80 and 1.85 Ma based on ⁴⁰Ar/³⁹Ar dating techniques, respectively. Compared to the meager Pleistocene bat record from elsewhere on mainland Africa, the Olduvai bat assemblage, although richer, is similar in the predominance of vespertilionids. The East African Olduvai bat fauna differs from Pleistocene faunas from South Africa in including both Myzopoda and Cardioderma but lacking both hipposiderids and rhinolophids. These taxonomic differences are likely the result of differential sampling due to variation in roosting site preferences (cave-dwelling vs. non-cave-dwelling taxa) and foraging habitats (open vs. forested) in East and South Africa.Item A new family of large omnivorous bats (Mammalia, Chiroptera) from the late Eocene of the Fayum Depression, Egypt, with comments on use of the name "Eochiroptera". (American Museum novitates, no. 3857)(American Museum of Natural History., 2016-05-09) Simmons, Nancy B.; Seiffert, Erik Remington.; Gunnell, Gregg F.A new fossil from the late Eocene BQ-2 locality in the Birket Qarun Formation in the Fayum Depression of northern Egypt (dated to ~37 mybp) does not fit within the diagnosis of any previously described family of bats from Africa or any other continent. Known from a partial maxilla, this taxon has dilambdodont tribosphenic molars with a well-developed, symmetrical, W-shaped ectoloph lacking a distinct mesostyle but with a strong parastyle and shallow U-shaped ectoflexus--all traits that are found in most archaic bat families and that are probably plesiomorphic for bats. However, this taxon also has an M2 with a large metaconule cusp and a large, bulbous hypocone set low on the posterolingual corner of the tooth, neither of which occur in any known bat family, living or extinct. Also notable is the size of the new BQ-2 bat, which appears to have been approximately the same size as the largest extant bats with dilambdodont dentitions, falling well within the size range of plant-eating megabats and carnivorous bats from several extant lineages. The combination of traits in the new BQ-2 bat suggests that it was omnivorous, probably including insects, small vertebrates, and plant material [in] its diet. In this regard it represents an ecological niche previously unknown among archaic Eocene bats, which are otherwise thought to have been strictly animalivorous. Because extinct Eocene bat families exhibit considerable mosaic evolution in morphological traits, do not seem to have inhabited a uniform ecological niche, and do not form a monophyletic group, we argue against use of the name "Eochiroptera" to collectively refer to these taxa.Item Quaternary bat diversity in the Dominican Republic. (American Museum novitates, no. 3779)(American Museum of Natural History., 2013-06-21) Velazco, Paul M.; O'Neill, Hannah.; Gunnell, Gregg F.; Cooke, Siobhán B.; Rímoli, Renato O.; Rosenberger, Alfred L.; Simmons, Nancy B.The fossil record of bats is extensive in the Caribbean, but few fossils have previously been reported from the Dominican Republic. In this paper, we describe new collections of fossil bats from two flooded caves in the Dominican Republic, and summarize previous finds from the Island of Hispaniola. The new collections were evaluated in the context of extant and fossil faunas of the Greater Antilles to provide information on the evolution of the bat community of Hispaniola. Eleven species were identified within the new collections, including five mormoopids (Mormoops blainvillei, [dagger]Mormoops magna, Pteronotus macleayii, P. parnellii, and P. quadridens), five phyllostomids (Brachyphylla nana, Monophyllus redmani, Phyllonycteris poeyi, Erophylla bombifrons, and Phyllops falcatus), and one natalid (Chilonatalus micropus). All of these species today inhabitant Hispaniola with the exception of [dagger]Mormoops magna, an extinct species previously known only from the Quaternary of Cuba, and Pteronotus macleayii, which is currently known only from extant populations in Cuba and Jamaica, although Quaternary fossils have also been recovered in the Bahamas. Differences between the fossil faunas and those known from the island today suggest that dispersal and extirpation events, perhaps linked to climate change or stochastic events such as hurricanes, may have played roles in structuring the modern fauna of Hispaniola.