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Fossils of an insectivorous bat from the early Miocene of Panama are described as a new genus and species, Americanycteris cyrtodon (Chiroptera: Phyllostomidae: Phyllostominae). Americanycteris is a large phyllostomine bat, similar in size to the living species Chrotopterus auritus. Americanycteris cyrtodon can be distinguished from other closely related species by a posteriorly curved p4 and a thick labial cingulum on m1. Americanycteris cyrtodon occurs in two early Miocene vertebrate faunas from Panama. The holotype mandible with p4–m1 and an isolated p3 of A. cyrtodon were recovered from the early Hemingfordian (19–18 Ma) Centenario Fauna, and a mandible with p2 was found in the older late Arikareean (21 Ma) Lirio Norte Local Fauna. A similar large phyllostomine bat is known from the early Miocene Gran Barranca Fauna in Argentina. The presence of early Miocene phyllostomids in both North America and South America confirms the overwater dispersal of bats between the Americas before the late Miocene onset of the Great American Biotic Interchange. Pre-late Miocene chiropteran dispersals between the Americas were previously documented for the Emballonuridae and Molossidae. Although the five endemic New World families in the Noctilionoidea, including Phyllostomidae, were previously thought to be South American in origin, the oldest fossil records of noctilionoids (Mormoopidae and extinct Speonycteridae) are from the early Oligocene of Florida and one of the earliest records of the Phyllostomidae is from the early Miocene of Panama. The currently available fossil records from Panama and Florida suggest a possible North American origin for the Noctilionoidea. [ABSTRACT FROM AUTHOR]

Abstract: Xenarthrans (also called edentates) include modern armadillos, sloths, and numerous extinct clades (e.g., glyptodonts and ground sloths) that lack enamel on their teeth. In contrast to mammals with tooth enamel, which oftentimes preserves geochemical proxy data, paleoecological interpretations of xenarthrans based on geochemical analyses (e.g. stable isotopes) have been limited. Xenarthrans have evolved a distinctive outer dentine layer that seems to be the functional analog of enamel. Here we evaluate the physical and chemical properties of xenarthran outer dentine to understand its potential use for investigating geochemical proxies. The mean hardness (H) of xenarthran outer dentine (3.8) is significantly less than that of enamel (5.7) and there is no difference in H between the two main groups, i.e., armadillos (cingulates) and pilosans (sloths). Although the mean H does not change significantly during diagenesis, its range increases, indicating the replacement of secondary minerals (e.g., carbonate representing the lower range) within the original hydroxylapatite mineral lattice. Results of FT-IR analyses indicate that xenarthran outer dentine has a high degree of organics and H2O, similar to normal dentine, and its crystallinity index and carbonate content are affected in varying degrees during diagenesis. Thus, although xenarthran outer dentine functions like enamel, it retains compositional similarities to dentine. The uptake of rare earth elements (REE) was analyzed from three late Neogene localities in Florida as a proxy for understanding diagenesis in xenarthrans as compared to other mammals. Relative to modern specimens, the fossils have about two orders of magnitude higher concentrations of REE. Uptake rates vary significantly among different dental tissues, i.e., bone>dentine (both inner and outer)>enamel. REE concentrations of fossil vertebrate specimens vary significantly between different localities. The REE Index (ratio of outer dentine/bone or enamel/bone for a given specimen) is proposed here to evaluate relative diagenesis in xenarthrans and other mammals, respectively. Other (non-xenarthran) mammals tend to have a lower REE Index, interpreted to represent less diagenesis. Nevertheless, many xenarthrans likewise have a low REE Index relative to other mammals at the same locality, indicating a similar degree of diagenesis. While the REE Index will likely be a reliable indicator of relative diagenesis in xenarthrans, the outer dentine provides challenges to the ultimate goal of interpreting proxy geochemical (e.g., stable isotope) data from these extinct mammals. [Copyright &y& Elsevier]

The article focuses on the fossils of Anchiterium clarencei, a three-toed horse from the middle Miocene of North America. It notes that collaboration between the Smithsonian Tropical Research Institute and the University of Florida paved the way for new collections of fossil vertebrates. It cites the specimen's significance to morphology, distribution, and paleocology. Meanwhile, the southern extreme of the Anchiterium clarencei's biogeographic range confirms its taxonomic allocation.

Abstract: The first appearance of mammoth (Mammuthus) is currently used to define the beginning of the Irvingtonian North American Land Mammal Age at about 1.4 Ma. Thereafter, mammoth fossils are common and widespread in North America until the end of the Pleistocene. In contrast to this generally accepted biochronology, recent reports have asserted that mammoth occurs in late Pliocene (ca. 2.5 Ma) alluvium from the Santa Fe River of northern Florida. The supposedly contemporaneous late Pliocene fossil assemblage from the Santa Fe River that produced the mammoth specimens actually consists of a mixture of diagnostic Blancan (late Pliocene) and late Rancholabrean (latest Pleistocene) species. Fossil bones and teeth of the two mammalian faunas mixed together along the Santa Fe River have significantly different rare earth element (REE) signatures. The REE signatures of mammoth are indistinguishable from those of Rancholabrean mammals, yet they are different from those of diagnostic Blancan vertebrates from these same temporally mixed faunas of the Santa Fe River. Thus, no evidence for late Pliocene mammoth exists in Florida, and mammoth fossils remain reliable biochronological indicators for Irvingtonian and Rancholabrean terrestrial sequences throughout mid- and lower-latitude North America. [Copyright &y& Elsevier]

Reports on discoveries concerning the diets, ecology, and extinction of ancient horses that lived in central Florida. Example of macroevolution that is found in the fossil record of horses; Carbon isotopic and tooth microwear data that provides information on the diet of the horses; Traditional morphological studies of tooth crown height; Species included in the six late Hemphillian Bone Valley horses.

Abstract: A fragmented fossil bone incised with the figure of a proboscidean was recently found at Vero Beach, Florida near the location where Late Pleistocene fauna and human bones were recovered from 1913 to 1916. This engraving may represent the oldest and only existing example of Terminal Pleistocene art depicting a proboscidean in the Americas. Because of the uniqueness, rarity, and potential antiquity of this specimen, caution demanded that a variety of tests be used in an attempt to verify its authenticity. The mineralized bone was identified as mammoth, mastodon, or giant sloth. Rare earth element analysis was consistent with the fossil bone being ancient and originating at or near the Old Vero site (8-IR-9). Forensic analysis suggests the markings on the bone are not recent. Optical microscopy results show no discontinuity in coloration between the carved grooves and the surrounding material indicating that both surfaces aged simultaneously. Scanning electron microscopy (SEM) revealed that the edges of the inscription are worn and show no signs of being incised recently or that the grooves were made with metal tools. In addition, the backscattered SEM images suggest there is no discontinuity in the distribution of light and heavy elements between the scribed region and the surrounding bone indicating that both surfaces aged in the same environment. This is very different from an intentional mark made on the bone for comparison. Energy dispersive x-ray spectroscopy (EDXS) shows that the surface contains significant amounts of calcium, phosphorus, oxygen, and carbon typical of a mineralized bone surface. Examination of a cast and mold of the incised bone by Reflectance Transformation Imaging (RTI) also provided no evidence that the engraving was made recently. All of these results are consistent with the mammoth engraving being authentic. [Copyright &y& Elsevier]