Results 281 to 290 of about 59,296 (338)
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2017
The amphibians prey on small invertebrates. Their teeth are sharply pointed, with one cusp in larvae and usually two in the adult. Adult teeth are usually divided into a distal functional tip and a basal pedicel, ankylosed to the jaw bone. The burrowing caecilians have robust skulls and relatively large, strong piercing teeth in both jaws.
Barry Berkovitz, Peter Shellis
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The amphibians prey on small invertebrates. Their teeth are sharply pointed, with one cusp in larvae and usually two in the adult. Adult teeth are usually divided into a distal functional tip and a basal pedicel, ankylosed to the jaw bone. The burrowing caecilians have robust skulls and relatively large, strong piercing teeth in both jaws.
Barry Berkovitz, Peter Shellis
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Quo vadis amphibia? Global warming and breeding phenology in frogs, toads and salamanders
, 2014As the earth is getting warmer, many animals and plants have shifted their timing of breeding towards earlier dates. However, there is substantial variation between populations in phenological shifts that typically goes unexplained. Identification of the
G. While, T. Uller
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SEX DIFFERENTIATION IN AMPHIBIA
Nature, 1946THE research which is summarized below was based on the well-known investigations of Witschi, who showed that at an early stage of development the amphibian gonad consists of a cortex and medulla. At a later stage, sex differentiation is marked by an increase of cortex relative to medulla or vice versa.
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THE FORMATION OF THE NOTOCHORD IN THE AMPHIBIA
, 1903A study of the mode of development of the notochord in the common toad, Bufo lentiginosus, and of the frog, Rana palustris, has brought to light certain points that have a bearing on the formation of the same structure in related groups. A vast amount of
H. D. King
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The Occurrence of Mercury in Amphibia
Environmental Letters, 1975Studies have been made of the distribution of mercury and its occurrence as methylmercury in the organs of amphibia collected from different sites mainly in Slovenia, Yugoslavia, including the area around the mercury mine at Idrija. Liver accumulates the highest amounts of mercury, up to 2 ppm in apparent background areas, with values up to 0.5 ppm in ...
P. Stegnar, A.R. Byrne, L. Kosta
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1969
The first postulation of a virus infection of an amphibian was made over thirty years ago. The presence of intranuclear acidophilic inclusion bodies in renal adenocarcinoma cells of Rana pipiens and an increased incidence of tumors in frogs receiving cell-free tumor extracts led Lucke (1934, 1938) to suggest a viral etiology of the tumor that bears his
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The first postulation of a virus infection of an amphibian was made over thirty years ago. The presence of intranuclear acidophilic inclusion bodies in renal adenocarcinoma cells of Rana pipiens and an increased incidence of tumors in frogs receiving cell-free tumor extracts led Lucke (1934, 1938) to suggest a viral etiology of the tumor that bears his
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1974
Except for Antarctica and Tierra del Fuego (the latter extending to 55 °00′S), Tasmania (reaching to 43 °40′S) is the southernmost continental land mass in the Southern Hemisphere. New Zealand, although of relatively large area (268,676 km2), and extending to 47 °00′S, has an impoverished, unbalanced and distinctly insular vertebrate fauna, together ...
A. A. Martin, M. J. Littlejohn
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Except for Antarctica and Tierra del Fuego (the latter extending to 55 °00′S), Tasmania (reaching to 43 °40′S) is the southernmost continental land mass in the Southern Hemisphere. New Zealand, although of relatively large area (268,676 km2), and extending to 47 °00′S, has an impoverished, unbalanced and distinctly insular vertebrate fauna, together ...
A. A. Martin, M. J. Littlejohn
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The Quarterly Review of Biology, 1962
The origin of land vertebrates is a constant subject of discussion. Recent findings in zoology and paleontology (Latimeria, Ichthyostega, Hesperoherpeton, etc.) have supplied many new arguments, but the results arrived at by various authorities show considerable differences.
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The origin of land vertebrates is a constant subject of discussion. Recent findings in zoology and paleontology (Latimeria, Ichthyostega, Hesperoherpeton, etc.) have supplied many new arguments, but the results arrived at by various authorities show considerable differences.
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DNA replication in the amphibia
Chromosoma, 1975Autoradiographic techniques were used to measure rate of replication and length of the replication unit in cultured cells of Scaphiopus couchi, Bufo cognatus, Rana clamitans, and Triturus viridescens, having nuclear DNA amounts in the ratio 1:4:7:39 respectively.
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2011
The Pliocene of Laetoli (Tanzania) has produced a taxonomically unbalanced fauna of amphibians and squamate reptiles. Amphibians are represented by only two specimens belonging to indeterminate anurans. Similarly, lizards are comprised of two specimens that are referred to an indeterminate acrodontan and an indeterminate scincomorphan.
Salvador Bailon, Jean-Claude Rage
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The Pliocene of Laetoli (Tanzania) has produced a taxonomically unbalanced fauna of amphibians and squamate reptiles. Amphibians are represented by only two specimens belonging to indeterminate anurans. Similarly, lizards are comprised of two specimens that are referred to an indeterminate acrodontan and an indeterminate scincomorphan.
Salvador Bailon, Jean-Claude Rage
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