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Paleogeography reconstruction of the Early Triassic world (left panel), showing that fishes and ichthyosaurs vacated the equator during the Smithian, with tetrapods exclusively occurring in the northern and southern middle to high latitudes…

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from article Ancient lethal hothouse

A scanning electron microscope image of the Early Triassic conodont Neospathodus, which is used for temperature reconstruction in this study.

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from article Paleogenomics

Diagram of the massively parallel picoliter-scale sequencing method, which accommodates 1.6 million reads, each approximately 100 base pairs in length.

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from article Paleogenomics

Histological micrograph of a Rhamphorhynchus (pterosaur from the Jurassic Period) radius in cross section. Scale bar: 100 micrometers.

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from article Phylogenetics: predicting rarity and endangerment

Phylogenetic tree of the family Hominidae [consisting of humans (Homo sapiens) and the great apes—orangutan (Pongo pygmaeus), common chimpanzee (Pan troglodytes), pygmy chimpanzee (Pan paniscus), and gorilla (Gorilla gorilla)], with branch lengths…

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from article Phylogenetics: predicting rarity and endangerment

(Top) Number of mammal species within various IUCN Red List categories. (Bottom) Percent of threatened (critically endangered + endangered + vulnerable) species within each major mammalian order; primates, including the great apes, contain the…

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from article Wood supply and demand

U.S. annual wood pulp production, 1900–2009. (Sources: Forest Service, Commerce Department, American Forest & Paper Association, International Woodfiber Report)

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from article Wood supply and demand

U.S. annual paper and paperboard consumption, and real gross domestic product (GDP), 1970–2009. [Sources: U.S. Bureau of Economic Analysis (GDP); American Forest & Paper Association (apparent consumption, including wet machine board and construction…

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from article Wood supply and demand

Annual U.S. consumption of paper and paperboard by principal category, 1970–2009. [Source: American Forest & Paper Association (excluding wet machine board and construction paper)]

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from article Wood supply and demand

U.S. solid wood and composite wood consumption as a percentage of domestic production.

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from article Wood supply and demand

U.S. timber growing stock net annual growth and removals, billions of cubic feet, 1986–2006.

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from article Wood supply and demand

U.S. real price indexes for delivered timber commodities, 1982–2009. [Source: Bureau of Labor Statistics, Producer Price Indexes (deflated using all-commodity producer price index)]

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from article Homo floresiensis: further insights

Homo floresiensis (LB1) skull and jaw. Note the retreating forehead and low, small cranium; the mound of bone over the eye orbit; the forward-sloping face; and the lack of a protruding chin. (Photo courtesy of Debbie Argue)

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from article Homo floresiensis: further insights

Comparison of mandibles. (a) View of a Homo floresiensis mandible. Note the internal buttressing at the inside front of the jaw. In addition, this individual had a full complement of adult teeth. (b) View of a Homo sapiens mandible. Note the lack of…

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from article Homo floresiensis: further insights

Phylogenetic tree showing the most likely placement for Homo floresiensis. (Illustration courtesy of L. Abbott, Biotext Pty Ltd, Canberra, Australia)

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from article Acheulean

Three views of an Acheulean handaxe from the site of Kamoa (Democratic Republic of the Congo). The bifacial edge is visible in profile and is the intersection of the two worked faces, shaped by the scars resulting from multiple flake removals. Scale…

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from article Vertebrate origins

Interrelationships among deuterostome taxa. (a) Among deuterostome phyla in relation to protostomes. (b) Among chordate subphyla. (c) Among vertebrate fish taxa. (d) Among urochordate classes.

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from article Vertebrate origins

Comparison of the three vertebrate brain regions and gene expression patterns with amphioxus and ascidian. Each gene expression pattern supports a hypothesis of homology for the fore/midbrain, isthmus/cerebellum, and hindbrain regions with the…

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from article Vertebrate origins

Gene number estimates. Shaded bars indicate results from completed genome projects; open bars are estimated values. Note that the value for “human” is representative for other vertebrates examined, including mouse and pufferfish. (Modified from M.…

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from article Post-Paleozoic ecological complexity

Two contrasting relative abundance distributions from Ordovician and Pleistocene assemblages of skeletonized bottom-dwelling marine animals, representing early Paleozoic and late post-Paleozoic time intervals, respectively. Abundances are shown on a…

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from article Post-Paleozoic ecological complexity

(a) Simple and (b) complex model relative abundance distributions (RADs) are shown as the proportions of individuals belonging to each species in a community, with species ordered from most to least abundant. Distributions were calculated with the…

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from article Post-Paleozoic ecological complexity

(a) Percentages of complex RADs for fossil assemblages in the Paleozoic and post-Paleozoic are shown. All statistically significant RADs are summarized within successive geologic time periods as mean values (circles) and error bars indicating one…

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from article Bubble-rafting snails

(a) Live bubble-rafting violet snail (Janthina exigua) with float and egg capsules (labeled “e”) [photo courtesy of Denis Riek; www.roboastra.com]. (b) Live female wentletrap (Epifungium ulu) with egg mass (labeled “e”) and dwarf male (indicated by…

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from article Bubble-rafting snails

Evolutionary relationships of janthinids and epitoniids. (Left) Reduced evolutionary tree showing the results of a multigene DNA analysis of violet snails (top four species), wentletraps, and other putative benthic sister lineages. Violet snails are…

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from article Dino-Birds

Diagram of theropod dinosaur and bird evolution showing that primitive feathers, first known from Sinosauropteryx, go back a long way in theropod history. True feathers appeared later within the major group Maniraptora.

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from article Dino-Birds

Nicknamed “Fuzzy raptor,” this spectacularly preserved juvenile dromaeosaur from Liaoning shows the typical long grasping hands and swiveling wrist bones together with extensive preservation of feathers around the body and limbs. (Reprinted with…

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from article Phthalates in western Aleutian Island seabirds

Map of islands from which samples have been collected (2009–2014).

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from article Indohyus: the origin of whales

A block of sediment showing several disarticulated bones of Indohyus. At least 25 individuals of various ages were preserved in this death assemblage.

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from article Indohyus: the origin of whales

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from article Indohyus: the origin of whales

The skull of Indohyus (RR 208) has a middle ear cavity that was filled with air in life. This cavity has been filled in with sediment during the fossilization process. The ear is broken in this specimen, showing the thickness of the medial wall.…

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from article Indohyus: the origin of whales

Diagram showing that Indohyus is the closest fossil relative to cetaceans, with Hippopotamus being the closest living relative.

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from article Earliest evidence of bilaterians

(a) Map showing the location of the Tacuarí trace fossils. The asterisk indicates the fossil locality. (b) General view of the area. (c) Outcrop of the Tacuarí Formation showing the fine-grained strata where the trace fossils typically occur. (d)…

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from article Earliest evidence of bilaterians

Schematic block diagram of the trace fossil locality illustrating the stratigraphic relationship between the Tacuarí strata and the intrusive granite. The Tacuarí strata were initially deposited horizontally on the seafloor (on top of the red…

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from article Earliest evidence of bilaterians

(a) Granite intruding through the fossil-bearing strata. The intrusive nature of the granite is well shown by the sharp and discordant (perpendicular) contact between the granite and the sedimentary layers. (b) Close-up view from the granite and…

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from article Earliest evidence of bilaterians

Images of the Tacuarí trace fossils: Simple, sinusoidal (sine curve–shaped), and unbranched feeding trails preserved and oriented parallel to the silty–sandy layers (a–d).

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from article Ichnology

Zoological affinities of trace fossils. (a) Structure produced by the modern terebellid polychaete Cirriformis sp. that produces a Rosselia-like burrow. (b) Trace fossil Rosselia socialis, Upper Cretaceous of Alberta.

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from article Ichnology

Distribution of ichnofacies based on the type of substrate.

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from article Ichnology

Cruziana ichnofacies that is typical of offshore marine environments. (Modified from S. G. Pemberton et al., 2001)

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from article Ichnology

Burrow-enhanced permeability and development of superpermeability in the Jurassic Arab-D interval, Ghawar Field, Saudi Arabia. (Modified from S. G. Pemberton and M. K. Gingras, 2005)

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from article Fossil record of vertebrate responses to global warming

Shifts in carbon (circles) and oxygen (triangles) isotopic composition of the ocean during the PETM, as seen at Ocean Drilling Program Site 690 near Antarctica. For practical reasons, isotopic ratios are given in delta notation, where δ18O =…

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from article Fossil record of vertebrate responses to global warming

Species diversity of mammals and lizards across the PETM in Wyoming. Species diversity is statistically corrected for sample size (that is, rarefied). Because of this correction, the increase in lizard diversity near the PETM is subdued with respect…

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from article Fossil record of vertebrate responses to global warming

Reconstruction of the head of Suzanniwana patriciana, one of the immigrant lizards in Wyoming, during the PETM. Known portions of the cranial skeleton are tinted. This species is a primitive relative of the extant basilisks (Basiliscus,…

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from article Effects of global warming on polar bears

Wrangel Island, Russia.

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from article Effects of global warming on polar bears

Number of bears recorded on Wrangel Island during ice-free seasons in 2004–2010.

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from article Effects of global warming on polar bears

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from article Effects of global warming on polar bears

Percentage of bears in various physical conditions observed on Wrangel Island during ice-free seasons in 2002–2010.

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from article Effects of global warming on polar bears

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from article Rhyniopsida

Rhynia. (a) Reconstruction showing leafless axis, basal rhizome with rhizoids (hairs), and fusiform, terminal sporangia. (b) Photomicrograph of transverse section of petrified stem. (c) Central xylem (vascular) strand. (After J. Walton, An…

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from article Kale

Kale (Brassica oleracea var. acephala). (Photo courtesy of Howard F. Schwartz, Colorado State University)

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from article Olive

Olive tree (Olea europaea). (Photo courtesy of Piero Amorati, IC Croce, Casalecchio di Reno; www.Bugwood.org)

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