Zoology

A new elpistostegalian from the Late Devonian period has been discovered that shows disparity in the group and represents a previously hidden ecological expansion, a secondary return to open water, near the origin of limbed vertebrates.

The discovery of a male-specific sex hormone in the mosquito <em>Anopheles gambiae</em> may allow new strategies for the control of this notorious disease vector.

To perch safely, large birds minimize the distance flown after stalling when swooping up from a dive to a perch, but not the time or energy required.

Select chemical compounds enriched in human odour activate an olfactory glomerulus in the brain of Aedes aegypti mosquitoes, which strengthens host-seeking behaviour and helps explain their strong preference for biting humans.

An extinction-risk assessment of reptiles shows that at least 21.1% of species are threatened by factors such as agriculture, logging, urban development and invasive species, and that efforts to protect birds, mammals and amphibians probably also benefit many reptiles.

Analysis of inertial characteristics across 22 bird species shows that evolution has selected for avian manoeuvrability using both stable and unstable flight dynamics.

The presence of a variety of highly derived spiral ganglion structures of the inner ear is associated with diverse echolocation strategies in yangochiropteran bats and distinguishes them from Yinpterochiroptera.

Three-dimensional reconstructions of morphology and flight mechanics of the beetle Paratuposa placentis reveal adaptations that enable extremely small insects to fly at speeds similar to those of much larger insects.

An analysis of cancer mortality data for zoo mammals highlights marked differences across mammalian orders and an influence of diet, and shows that mortality risk is largely independent of body mass and life expectancy across species.

Stegouros elengassen, an ankylosaur from the late Cretaceous of Chile, has a large tail weapon, named a macuahuitl after the Aztec club, with a frond-like structure formed by seven pairs of laterally projecting osteoderms encasing the distal half of the tail.

Growth series of Palaeozoic stem lampreys do not include a filter-feeding larval phase seen in modern lampreys, which suggests that modern lamprey larvae are a poor model of vertebrate ancestry.

The global abundance of oceanic sharks and rays has decreased by 71% since 1970 and 24 species are threatened with extinction owing to a concomitant increase in fishing pressure.

Analysis of humeri from fossils that span the fin-to-limb transition reveal that the change in the humerus shape is driven by both ecology and phylogeny, and is associated with functional trade-offs related to locomotor performance.

Analyses of molecular, anatomical, pigmentation and ecological characteristics of nearly all of the approximately 240 species of cichlid fishes in Lake Tanganyika show that the massive adaptive radiation occurred within the confines of the lake through trait-specific pulses of accelerated evolution.

A jigsaw-style configuration of interlocking structures identified in the elytra of the remarkably tough diabolical ironclad beetle, Phloeodes diabolicus, is used to inspire crush-resistant multilayer composites for engineering joints.

A fossil egg unearthed from Cretaceous deposits in Antarctica is more than 20 cm long, exceeds all known nonavian eggs in volume, is soft-shelled, and was perhaps laid by a giant marine lizard such as a mosasaur.

Advanced deep-sea imaging tools yield insights into the structure and function of mucus filtration houses built by midwater giant larvaceans.

The transverse tarsal arch, acting through the inter-metatarsal tissues, is important for the longitudinal stiffness of the foot and its appearance is a key step in the evolution of human bipedalism.

The leg-enriched sensory appendage protein, SAP2, confers pyrethroid resistance to Anopheles gambiae, through high-affinity binding of pyrethroid insecticides; an observed selective sweep in field mosquitoes mirrors the increasing resistance reported in Africa.

Three-dimensionally preserved fossils of Parmastega aelidae, a newly described tetrapod from the earliest Famennian (Late Devonian) of Russia, provide detailed insights into the morphology and palaeobiology of the earliest tetrapods.

Aerial sampling in the Sahel of Mali reveals large numbers of windborne malaria mosquitoes that had recently fed on blood and could cover hundreds of kilometres in a single night.

CRISPR–Cas9 engineering of the Drosophila Atpα gene (encoding the α-subunit of the sodium pump) is used to study the ability of mutations that evolved independently in several insect orders to confer resistance to keystone plant toxins.

Comparisons across terrestrial and marine ectotherms reveal that marine species experience temperatures closer to their upper thermal limits, and that local extirpations related to warming are more common in the ocean.

Micro-computed tomography and magnetic resonance imaging of a growth series of the coelacanth Latimeria chalumnae traces the ontogeny of the brain and neurocranium, which sheds light on neurocranial evolution in sarcopterygian fishes.

Treatment of female Anopheles gambiae mosquitoes with atovaquone causes arrest of the Plasmodium falciparum parasite in the midgut, and this holds promise for malaria eradication in areas with insecticide-resistant mosquito populations.

Mixed-effects logistic regression modelling of a dataset of individual reproductive behaviours shows fitness pay-offs of cooperative versus mixed cooperative and parasitic reproductive strategies are approximately equal in female greater anis (Crotophaga major).

The ancestral tribosphenic therian chewing stroke is conserved in Monodelphis domestica, and couples tooth-row eversion and inversion in jaw opening and closing, respectively, with a rotational grinding stroke.

Evidence from hippocampal place cells shows that path-integration gain, previously thought to be a constant factor in the computation of location, is flexible and can be rapidly fine-tuned.

Quantitative explorations using biomechanics and robotics of the gait of Orobates, a stem amniote, indicate that the development of relatively erect, power-saving and balanced locomotion preceded the diversification of crown amniotes

A phylogenetic assessment based on Raman microspectroscopy of pigment traces in fossilized eggshells from all major dinosaur clades reveals that eggshell coloration and pigment pattern originated in nonavian theropod dinosaurs.

Wildebeest, particularly during their long migrations under hot arid conditions, gain a considerable increase in range as a result of having highly efficient muscles.

Biomechanical analyses of mammaliaform and cynodont fossils demonstrate that miniaturization drove the evolutionary transformation of the mammalian jaw, which preceded the optimization of bite force-to-joint load in the mandible

Experimental data from, and mathematical modelling of, colonies of the clonal raider ant Ooceraea biroi demonstrate that increases in group size generate division of labour among similar individuals, increased homeostasis and higher colony fitness.

Female zebra finches exhibited categorical perception of colour signals, as they categorized colour stimuli that varied along a continuous scale and showed increased discrimination between colours from opposite sides of the category boundary compared to equally different colours from within a category.

Two populations of Anolis lizards that survived Hurricanes Irma and Maria had larger toepads, longer forelimbs and shorter hindlimbs relative to the pre-hurricane populations, which suggests hurricane-induced natural selection.

Morphological studies and phylogenetic analyses based on the newly discovered Early Cretaceous eutherian mammal Ambolestes zhoui show that the oldest purported metatherian Sinodelphys is instead a eutherian.

A Review of the cues and mechanisms used by animals to navigate over long distances, with a particular emphasis on magnetoreception.

Computed tomography scanning of the Triassic fossil Megachirella wachtleri combined with a broad morphological and molecular phylogenetic analysis of reptile relationships confirm it as the most primitive stem squamate.

Using estimates of metabolic costs of the brain and body, mathematical predictions suggest that the evolution of adult Homo sapiens-sized brains and bodies is driven by ecological rather than social challenges and is perhaps strongly promoted by culture.

The Spaid protein is identified and shown to be responsible for the male-killing effects of Spiroplasma poulsonii in Drosophila.

A derivation of Hamilton’s rule that considers explicit environmental stochasticity can predict when organisms should pay a cost to influence the variance in the reproductive success of their relatives, formalizing the link between bet-hedging and altruism.

Analysis and modelling of locomotor characteristics of two pursuit predator–prey pairs show that hunts at lower speeds enable prey to use their maximum manoeuvring capacity and favour prey survival.