The Field Museum of Natural History (FMNH), also known as The Field Museum, is a natural history museum in Chicago, Illinois, and is one of the largest such museums in the world. The museum is a popular natural-history museum for the size and quality of its educational and scientific programs, as well as due to its extensive scientific-specimen and artifact collections. The permanent exhibitions, which attract up to two million visitors annually, include fossils, current cultures from around the world, and interactive programming demonstrating today's urgent conservation needs. The museum is named in honor of its first major benefactor, the department-store magnate Marshall Field. The museum and its collections originated from the 1893 World's Columbian Exposition and the artifacts displayed at the fair.The museum maintains a temporary exhibition program of traveling shows as well as in-house produced topical exhibitions. The professional staff maintains collections of over 24 million specimens and objects that provide the basis for the museum's scientific-research programs. These collections include the full range of existing biodiversity, gems, meteorites, fossils, and rich anthropological collections and cultural artifacts from around the globe. The museum's library, which contains over 275,000 books, journals, and photo archives focused on biological systematics, evolutionary biology, geology, archaeology, ethnology and material culture, supports the museum's academic-research faculty and exhibit development. The academic faculty and scientific staff engage in field expeditions, in biodiversity and cultural research on every continent, in local and foreign student training, and in stewardship of the rich specimen and artifact collections. They work in close collaboration with public programming exhibitions and education initiatives.
Throughout their range, the North American River Otter (Lontra canadensis), Common Muskrat (Ondatra zibethicus) and North American Beaver (Castor canadensis), have been exploited for their fur for centuries, leading to local-scale extirpations. More recently, these species have begun to return to landscapes where they have been absent since the commercial fur trade. The reappearance of these species in human-dominated, heavily-altered landscapes merits attention both for conservation science and potential ecosystem services. In particular, these species have begun to reappear throughout urban waterways in some of the most densely populated cities in North America, particularly in Chicago, Illinois (USA). This review examines the ecology of these species, their historical interactions with humans, and synthesizes the available case study data that assesses their occurrence in urban areas. These urban landscape appearances also facilitate discussion on human conflict mitigation and potential conservation practices moving forward. We highlight the need for continual population surveys of these animals, to both better understand how semi-aquatic mammal populations cope in such human-altered landscapes and anticipate their activities when city planning. Additionally, this review emphasizes the benefit of urban green spaces and offers practical solutions, with examples like floating wetlands, which serve an ecological function both for humanity and wildlife. The occurrence of these species in our urban waterways may be an indication of their adaptability, or conversely, a sign of how little natural wetland and riparian habitat remains for them. Research is underway, and more is needed, to better answer this question.
Stigmaria rooted late Palaeozoic lycopsid trees, and its development and homologies have long been debated. Micro-computed tomography of stigmarian apex and distal axis cast fossils reveals exceptional and surprising three-dimensional preservation of the internal system of rootlet anatomy, including immature traces that articulate to the apical plug prior to integrating proximally with the stele, reorientation of traces from longitudinal to radial behind the apex, and trace anastomoses. This record of development indicates that the stigmarian apical meristem has characteristic developmental features typical of vascular plant shoots, consistent with apical production of the plant morphogenic hormone auxin and its transport away from the apex. Importantly, the stigmarian meristem structure differs fundamentally from that of the small rooting stocks of related plants, inviting reconsideration of homology between Stigmaria and other lycopsid rooting structures. The shoot-like developmental pattern of Stigmaria challenges the foundational assumption that roots develop by auxin transport towards the apex, offering a rare example in the fossil record of a lineage experimenting with developmental architecture in ways unseen in living plants. The employed methods give potential new life to thousands of cast fossils that may, too, preserve internal anatomy.
Amazon rainforests face intensifying water stress due to increases in vapour pressure deficit and changing hydrological regimes. Embolism resistance (Ψ50) is a critical metric of tree survival under drought conditions, it is defined as a plant's capacity to resist disruption of xylem water flow due to air bubble formation from water stress. However, measurements of Ψ50 are only available for a limited number of Amazon locations and species. Conversely, data on forest taxonomic composition are abundant across Amazonia, and if Ψ50 is conserved phylogenetically, these data could provide a way to scale-up drought resistance patterns. Here we evaluate Ψ50 measurements across non-flooded Amazonian tree taxa and reveal a moderate phylogenetic signal, with phylogenetic conservatism evident at the family-level. Notably, Fabaceae is amongst the most embolism-resistant tree families in Amazonia. Leveraging the phylogenetic signal we use species composition and tree size data from 448 forest plots across Amazonia to produce a macroecological assessment of Amazonian vulnerability to embolism. The resulting estimate spatial pattern reveals that forests in the Brazilian and Guiana Shield regions, where Fabaceae abundance is high, show strong resistance to embolism. In contrast, tree communities in Western Amazonia appear more vulnerable to embolism, suggesting a reduced capacity to withstand future drought conditions.
ABSTRACT Since 1982, the phylogeny, classification, and taxonomy of Dagini have undergone relatively few modifications. Previous studies, however, were usually based on limited groups of species or were restricted in geographic scope, making the relationships among these taxa inadequately understood and inconclusive. To clarify and better substantiate these relationships, this comprehensive phylogenetic analysis was undertaken to test the following questions: (1) Is the tribe Dagini monophyletic? (2) Is the genus Physemops Cresson, 1934 monophyletic? (3) What are the cladistic relationships among the genera included in Ephydrinae, including the phylogenetic position and monophyly of Brachydeutera Loew, 1862? (4) what are the putative synapomorphies for the other genera of Dagini? The analysis and tests are based on morphological characters from adult males and females. The analyses from both equal and implied weighting resulted in cladograms of 208 steps in length. Brachydeutera was recovered as a basal lineage and as sister group to the lineage giving rise to the tribes Scatellini, Dagini, and Ephydrini. As such, Brachydeutera is proposed as a new tribe (Brachydeuterini). The tribe Dagini was recovered as the sister lineage to the node giving rise to the tribes Scatellini and Ephydrini, with the latter two tribes as sister groups, and all currently valid and recognized genera, including subgenera and species groups, were recovered as monophyletic lineages. In the taxonomic section, diagnostic characters of the tribes Brachydeuterini and Dagini are provided, along with diagnoses of all included genera and species groups currently recognized within the tribe. In addition, identification keys to all subgenera and species groups are provided to facilitate their recognition.
