The phylogeny of megachiropteran bats (Mammalia: Chiroptera: Pteropodidae) has been investigated using several different molecular datasets. These studies differed widely in taxonomic and locus sampling, and their results tended to lack resolution of internal nodes and were themselves largely incongruent. To address this, we assembled a data set of 5 loci (up to 3.5 kbp from 12S rDNA, 16S rDNA, tDNA-valine, cytochrome b, and the nuclear gene c-mos) for 43 species of megachiropterans and 6 microchiropteran outgroups. We analyzed these data with direct optimization under equal costs for substitutions and indels. We used POY in a parallel setting, and searches consisted of replicated swapping + refinements (ratcheting, tree fusing, and iterative pass optimization). Our results indicate that Megachiroptera and all recognized genera (including Pteropus) are monophyletic, and that Melonycteris is the sister group of the clade containing all the other genera. Clades previously proposed using molecular data, as well as many new and traditional groups, were well-supported, and various sources suggest that the degree of conflict with morphological data may be considerably less marked than previously supposed. Analysis of individual loci suffer 70% loss in the number of compatible groups recovered across all analyses with respect to combined analyses. Our results indicate that, within Megachiroptera, nectarivory and cave-dwelling originated several times, but echolocation (used for obstacle detection) evolved only once. Megachiropterans likely originated in SE Asia-Melanesia, and colonized Africa at least four times.
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http://dx.doi.org/10.1111/j.1096-0031.2003.tb00385.x | DOI Listing |
J Comp Neurol
December 2020
School of Anatomical Sciences, University of the Witwatersrand, South Africa.
Small echolocating bats are set apart from most other mammals by their relatively large cerebellum, a feature that has been associated to echolocation, as it is presumed to indicate a relatively enlarged number of neurons in the cerebellum in comparison to other brain structures. Here we quantify the neuronal composition of the cerebral cortex, cerebellum and remaining brain structures of seven species of large Pteropodid bats (formerly classified as megachiropterans), one of which echolocates, and six species of small bats (formerly classified as microchiropterans), all of which echolocate. This chiropteran data is compared to 60 mammalian species in our dataset to determine whether the relatively large cerebellum of the small echolocating bats, and possibly that of the echolocating Pteropodid, contains a relatively enlarged number of neurons.
View Article and Find Full Text PDFJ Chem Neuroanat
December 2015
School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193 Johannesburg, South Africa; KSU Mammals Research Chair, Department of Zoology, King Saud University, Riyadh 11451, Saudi Arabia. Electronic address:
The present study describes the organization of the nuclei of the cholinergic, catecholaminergic, serotonergic and orexinergic systems in the brains of two members of Euarchontoglires, Lepus capensis and Tupaia belangeri. The aim of the present study was to investigate the nuclear complement of these neural systems in comparison to previous studies on Euarchontoglires and generally with other mammalian species. Brains were coronally sectioned and immunohistochemically stained with antibodies against choline acetyltransferase, tyrosine hydroxylase, serotonin and orexin-A.
View Article and Find Full Text PDFAnat Rec (Hoboken)
August 2011
School of Anatomical Science, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.
This study used magnetic resonance imaging (MRI) to determine the volume of the ventricular system in the brain of three adult male African elephants (Loxodonta africana). The ventricular system of the elephant has a volume of ∼240 mL, an order of magnitude larger than that seen in the adult human. Despite this large size, allometric analysis indicates that the volume of the ventricles in the elephant is what one would expect for a mammal with an ∼5 kg brain.
View Article and Find Full Text PDFJ Chem Neuroanat
November 2010
School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, Johannesburg, South Africa.
The current study describes, using immunohistochemical methods, the nuclear organization of the cholinergic, catecholaminergic and serotonergic systems within the brains of five microchiropteran species. For the vast majority of nuclei observed, direct homologies are evident in other mammalian species; however, there were several distinctions in the presence or absence of specific nuclei that provide important clues regarding the use of the brain in the analysis of chiropteran phylogenetic affinities. Within the five species studied, three specific differences (presence of a parabigeminal nucleus, dorsal caudal nucleus of the ventral tegmental area and the absence of the substantia nigra ventral) found in two species from two different families (Cardioderma cor; Megadermatidae, and Coleura afra; Emballonuridae), illustrates the diversity of microchiropteran phylogeny and the usefulness of brain characters in phylogenetic reconstruction.
View Article and Find Full Text PDFCladistics
October 2005
Department of Mammalogy, Division of Vertebrate Zoology, American Museum of Natural History, New York, NY 10024-5192, USA.
The phylogeny of megabats (Mammalia: Chiroptera: Megachiroptera) has been addressed only on molecular grounds, as little effort has previously been made to describe the impressive morphological variation of the group in terms of phylogenetically informative characters. Here we provide a morphological matrix of 236 characters from the integument, dentition, cranial and post-cranial skeleton, digestive apparatus and urogenital system. This data set covers most characters discussed previously in more restricted taxonomic contexts, as well a large number of new characters.
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