Museum of Texas Tech University

About: Museum of Texas Tech University is a based out in . It is known for research contribution in the topics: Phylogenetic tree & Cytochrome b. The organization has 66 authors who have published 193 publications receiving 4860 citations.

Biplane wing planform and flight performance of the feathered dinosaur Microraptor gui

Abstract: Microraptor gui, a four-winged dromaeosaur from the Early Cretaceous of China, provides strong evidence for an arboreal-gliding origin of avian flight. It possessed asymmetric flight feathers not only on the manus but also on the pes. A previously published reconstruction shows that the hindwing of Microraptor supported by a laterally extended leg would have formed a second pair of wings in tetrapteryx fashion. However, this wing design conflicts with known theropod limb joints that entail a parasagittal posture of the hindlimb. Here, we offer an alternative planform of the hindwing of Microraptor that is concordant with its feather orientation for producing lift and normal theropod hindlimb posture. In this reconstruction, the wings of Microraptor could have resembled a staggered biplane configuration during flight, where the forewing formed the dorsal wing and the metatarsal wing formed the ventral one. The contour feathers on the tibia were positioned posteriorly, oriented in a vertical plane for streamlining that would reduce the drag considerably. Leg feathers are present in many fossil dromaeosaurs, early birds, and living raptors, and they play an important role in flight during catching and carrying prey. A computer simulation of the flight performance of Microraptor suggests that its biplane wings were adapted for undulatory “phugoid” gliding between trees, where the horizontal feathered tail offered additional lift and stability and controlled pitch. Like the Wright 1903 Flyer, Microraptor, a gliding relative of early birds, took to the air with two sets of wings.

Assessing the Value of Natural History Collections and Addressing Issues Regarding Long-Term Growth and Care

Abstract: Natural history collections serve as important sources of biological data for scientists, educators, and the general public These collections are a crucial cornerstone for systematics, natural history, ecology, and many other specialized disciplines, whose research depends on either the specimen or the associated data Recent studies have provided baseline information pertaining to the monetary costs associated with collecting scientific specimens and curating and caring for those specimens after they have been accessioned into a natural history collection Here, we provide a synopsis of the primary benefits that natural history collections provide to science and society Furthermore, given that financial support is crucial for long-term growth and care, we present several ideas that should be considered by curators and users of systematic collections

New dinosaur species from the Upper Triassic Upper Maleri and Lower Dharmaram formations of Central India

Abstract: The beginning of dinosaur evolution is currently known based on a handful of highly informative Gondwanan outcrops of Ischigualastian age (late Carnian–early Norian). The richest Triassic dinosaur records of the southern continents are those of South America and South Africa, with taxonomically diverse faunas, whereas faunas from India and central Africa are more poorly known. Here, the known diversity of Gondwanan Triassic dinosaurs is increased with new specimens from central India, which allow a more comprehensive characterisation of these dinosaur assemblages. Five dinosauriform specimens are reported from the probable late Norian–earliest Rhaetian Upper Maleri Formation, including two new sauropodomorph species, the non-plateosaurian Nambalia roychowdhurii and the plateosaurian Jaklapallisaurus asymmetrica, a guaibasaurid and two basal dinosauriforms. The Lower Dharmaram Formation, probably latest Norian–Rhaetian in age, includes basal sauropodomorph and neotheropod remains, providing the second record of a Triassic Gondwanan neotheropod. The currently available evidence suggests that the oldest known Gondwanan dinosaur assemblages (Ischigualastian) were not homogeneous, but more diverse in South America than in India. In addition, the Upper Maleri and Lower Dharmaram dinosaur assemblages resemble purported coeval South American and European beds in the presence of basal sauropodomorphs. Accordingly, the current available evidence of the Triassic beds of the Pranhita–Godavari Basin suggests that dinosaurs increased in diversity and abundance during the late Norian to Rhaetian in this region of Gondwana.

Composition and Structure of Bat Assemblages in Paraguay: A Subtropical–Temperate Interface

Abstract: Little is known about geographic variation in the local composition of South American assemblages of mammals or the factors that may produce such variation. This is particularly unfortunate in Paraguay because it occurs at the interface of a number of phytogeographic regions (e.g., Cerrado, Chaco, Interior Atlantic Rainforest, and Pantanal) and is the point at which many temperate species reach their northern limits or at which tropical species reach their southern limits. Based on 2 years of intensive fieldwork, we documented the species and familial composition of bat assemblages at 25 sites throughout the country. We also estimated similarity among sites based on indices sensitive to presence or absence of species (Ochiai's index), to rank abundance of species (rank correlation index), or to relative abundance of species (Euclidean index). Geographic distance between sites accounted for little variation in composition based on presence-absence or rank abundances of species but accounted significantly for variation related to both identity and relative frequency of species. Distinct assemblages of species do not correspond to the 7 distinct biomes of the country; rather, strong differences exist between sites east (mesic) and west (xeric) of the Rio Paraguay. For the most part, these differences are related to dominance by molossids (e.g., Eumops patagonicus, Molossops temminckii, and Molossus molossus) and vespertilionids (e.g., Lasiurus ega, Myotis albescens, and M. nigricans) in dry regions versus phyllostomids (e.g., Artibeus fimbriatus, A. lituratus, and Sturnira lilium) in mesic regions. As a consequence, classification of sites into 2 broad biogeographic regions based on bat familial composition generally is concordant with that based on plants.