The Experts below are selected from a list of 1992 Experts worldwide ranked by ideXlab platform
Steven R. Bozarth - One of the best experts on this subject based on the ideXlab platform.
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Implications for Late Pleistocene Mastodon Diet from Opal Phytoliths in Tooth Calculus
Quaternary Research, 2001Co-Authors: Katrina E Gobetz, Steven R. BozarthAbstract:Abstract Calculus removed from the molar teeth of four American mastodons (Mammut americanum) contained opal phytoliths which reflect major dietary components. Three samples contained abundant grass phytoliths (ca. 86% of total), with long cells and trapezoidal pooid short cells dominant (ca. 25 and 31%, respectively). Dicot phytoliths from hackberry (Celtis sp.) seeds and indeterminate deciduous trees were rare (1–3%), though well preserved, whereas phytoliths from conifer trees were not recognizable in any of the samples. Comparative analysis of Calculus from modern and fossil browsers and mixed feeders implies that dicots and conifers are nearly invisible in the phytolith record. This scarcity may result from poor preservation, low silica production in woody taxa, and/or animals' selection of young, silica-poor leaves and shoots. However, abundant grass phytoliths in the mixed feeders suggest that presence versus absence of grass phytoliths may distinguish mixed feeders and grazers from browsers. Mastodons are traditionally considered browsers, but grass phytolith assemblages in three individual mastodons contained similarly high concentrations of pooids, suggesting that these grasses were a significant part of the diet. Abundant pooid phytoliths, in addition to diatoms, indicate that these mastodons grazed in a cool, moist late Pleistocene environment, possibly near water.
Leonardo Dos Santos Avilla - One of the best experts on this subject based on the ideXlab platform.
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Ancient diet of the Pleistocene gomphothere Notiomastodon platensis (Mammalia, Proboscidea, Gomphotheriidae) from lowland mid-latitudes of South America: Stereomicrowear and Tooth Calculus analyses combined
Quaternary International, 2012Co-Authors: Lidiane Asevedo, Gisele R. Winck, Dimila Mothé, Leonardo Dos Santos AvillaAbstract:Abstract The gomphothere assemblage from the Pleistocene of Aguas de Araxa (Minas Gerais State, Brazil) is composed of several isolated teeth, cranial and postcranial fragments assigned to a single population of Notiomastodon platensis . The age profile suggests decline of the population, due to the large amount of senile and mature adult individuals. The mortality event probably occurred during a long period of low humidity, which could cause a mass death of the proboscideans around water refuges. The ancient feeding ecology of these gomphotheres was reconstructed through stereomicrowear and plant microfossils from teeth calculi, using molars from four age classes. The enamel microwear patterns were recognized according to published studies, whereas the average scratch and pit values were compared to an extant ungulates database. The plant microfossils were chemically recovered and microscopically analyzed. Isotopic analyses of the South American gomphotheres suggest a wide dietary range for N. platensis, except for two localities: Santiago del Estero (Argentina) and La Carolina (Ecuador). For these, isotope analyses suggested an exclusive C4 diet, whereas all other South American localities studied so far indicate an exclusive C3 diet or a mixed C3 and C4 diet. The results also support the apparent latitudinal gradient of C3/C4 grasses. The stereomicrowear analyses for N. platensis exhibited average scratch and pit values, which places it within the extant mixed-feeder morphospace. The higher frequency of fine scratches indicated the ingestion of C3 grasses. Alternatively, the presence of coarse and hypercoarse scratches along with gouges and large pits suggested the ingestion of foliage and lignified portions. The plant microfossil analysis recovered fragments of a conifer tracheid and vessel elements with a ray of parenchyma cells, which corroborates the consumption of wood plants. Also, pollen grains (Polygonaceae), spores (Polypodiaceae) and fibers were found in the samples. According to the results, the Aguas de Araxa gomphotheres were feeding generalists and consumed wood elements, leaves and C3 grasses.
Katrina E Gobetz - One of the best experts on this subject based on the ideXlab platform.
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Implications for Late Pleistocene Mastodon Diet from Opal Phytoliths in Tooth Calculus
Quaternary Research, 2001Co-Authors: Katrina E Gobetz, Steven R. BozarthAbstract:Abstract Calculus removed from the molar teeth of four American mastodons (Mammut americanum) contained opal phytoliths which reflect major dietary components. Three samples contained abundant grass phytoliths (ca. 86% of total), with long cells and trapezoidal pooid short cells dominant (ca. 25 and 31%, respectively). Dicot phytoliths from hackberry (Celtis sp.) seeds and indeterminate deciduous trees were rare (1–3%), though well preserved, whereas phytoliths from conifer trees were not recognizable in any of the samples. Comparative analysis of Calculus from modern and fossil browsers and mixed feeders implies that dicots and conifers are nearly invisible in the phytolith record. This scarcity may result from poor preservation, low silica production in woody taxa, and/or animals' selection of young, silica-poor leaves and shoots. However, abundant grass phytoliths in the mixed feeders suggest that presence versus absence of grass phytoliths may distinguish mixed feeders and grazers from browsers. Mastodons are traditionally considered browsers, but grass phytolith assemblages in three individual mastodons contained similarly high concentrations of pooids, suggesting that these grasses were a significant part of the diet. Abundant pooid phytoliths, in addition to diatoms, indicate that these mastodons grazed in a cool, moist late Pleistocene environment, possibly near water.
Lidiane Asevedo - One of the best experts on this subject based on the ideXlab platform.
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Ancient diet of the Pleistocene gomphothere Notiomastodon platensis (Mammalia, Proboscidea, Gomphotheriidae) from lowland mid-latitudes of South America: Stereomicrowear and Tooth Calculus analyses combined
Quaternary International, 2012Co-Authors: Lidiane Asevedo, Gisele R. Winck, Dimila Mothé, Leonardo Dos Santos AvillaAbstract:Abstract The gomphothere assemblage from the Pleistocene of Aguas de Araxa (Minas Gerais State, Brazil) is composed of several isolated teeth, cranial and postcranial fragments assigned to a single population of Notiomastodon platensis . The age profile suggests decline of the population, due to the large amount of senile and mature adult individuals. The mortality event probably occurred during a long period of low humidity, which could cause a mass death of the proboscideans around water refuges. The ancient feeding ecology of these gomphotheres was reconstructed through stereomicrowear and plant microfossils from teeth calculi, using molars from four age classes. The enamel microwear patterns were recognized according to published studies, whereas the average scratch and pit values were compared to an extant ungulates database. The plant microfossils were chemically recovered and microscopically analyzed. Isotopic analyses of the South American gomphotheres suggest a wide dietary range for N. platensis, except for two localities: Santiago del Estero (Argentina) and La Carolina (Ecuador). For these, isotope analyses suggested an exclusive C4 diet, whereas all other South American localities studied so far indicate an exclusive C3 diet or a mixed C3 and C4 diet. The results also support the apparent latitudinal gradient of C3/C4 grasses. The stereomicrowear analyses for N. platensis exhibited average scratch and pit values, which places it within the extant mixed-feeder morphospace. The higher frequency of fine scratches indicated the ingestion of C3 grasses. Alternatively, the presence of coarse and hypercoarse scratches along with gouges and large pits suggested the ingestion of foliage and lignified portions. The plant microfossil analysis recovered fragments of a conifer tracheid and vessel elements with a ray of parenchyma cells, which corroborates the consumption of wood plants. Also, pollen grains (Polygonaceae), spores (Polypodiaceae) and fibers were found in the samples. According to the results, the Aguas de Araxa gomphotheres were feeding generalists and consumed wood elements, leaves and C3 grasses.
Dimila Mothé - One of the best experts on this subject based on the ideXlab platform.
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Ancient diet of the Pleistocene gomphothere Notiomastodon platensis (Mammalia, Proboscidea, Gomphotheriidae) from lowland mid-latitudes of South America: Stereomicrowear and Tooth Calculus analyses combined
Quaternary International, 2012Co-Authors: Lidiane Asevedo, Gisele R. Winck, Dimila Mothé, Leonardo Dos Santos AvillaAbstract:Abstract The gomphothere assemblage from the Pleistocene of Aguas de Araxa (Minas Gerais State, Brazil) is composed of several isolated teeth, cranial and postcranial fragments assigned to a single population of Notiomastodon platensis . The age profile suggests decline of the population, due to the large amount of senile and mature adult individuals. The mortality event probably occurred during a long period of low humidity, which could cause a mass death of the proboscideans around water refuges. The ancient feeding ecology of these gomphotheres was reconstructed through stereomicrowear and plant microfossils from teeth calculi, using molars from four age classes. The enamel microwear patterns were recognized according to published studies, whereas the average scratch and pit values were compared to an extant ungulates database. The plant microfossils were chemically recovered and microscopically analyzed. Isotopic analyses of the South American gomphotheres suggest a wide dietary range for N. platensis, except for two localities: Santiago del Estero (Argentina) and La Carolina (Ecuador). For these, isotope analyses suggested an exclusive C4 diet, whereas all other South American localities studied so far indicate an exclusive C3 diet or a mixed C3 and C4 diet. The results also support the apparent latitudinal gradient of C3/C4 grasses. The stereomicrowear analyses for N. platensis exhibited average scratch and pit values, which places it within the extant mixed-feeder morphospace. The higher frequency of fine scratches indicated the ingestion of C3 grasses. Alternatively, the presence of coarse and hypercoarse scratches along with gouges and large pits suggested the ingestion of foliage and lignified portions. The plant microfossil analysis recovered fragments of a conifer tracheid and vessel elements with a ray of parenchyma cells, which corroborates the consumption of wood plants. Also, pollen grains (Polygonaceae), spores (Polypodiaceae) and fibers were found in the samples. According to the results, the Aguas de Araxa gomphotheres were feeding generalists and consumed wood elements, leaves and C3 grasses.