The tetraradial or pentaradial fossil embryos and related hatched individuals from the early Cambrian Kuanchuanpu Formation are of great interest for understanding the early evolution of medusozoans. The phylogenetic and evolutionary significance of their external and internal characters (e.g. manubrium, tentacles, septa and claustra) is still controversial. Here we describe a new pentamerous medusozoan, Hanagyroia orientalis gen. et sp. nov., characterized by five well-developed perradial oral lips around a remarkably large manubrium, a conspicuous equatorial...

A key question in paleoecology and macroevolution is whether assemblages of species (paleocommunities) are persistent entities that endure over millions of years. Whilst community turnover in the face of abiotic change is the presumed norm, paleocommunities have been shown to persist for long time periods and regardless of environmental disruption. It remains an open question however, as to what processes allow for this. We investigate these questions by analyzing the Carboniferous brachiopod paleocommunities from the...

Quercus is one of the most important genera for considering its economic and ecological values, with approximately 500 species worldwide. Quercus group Cerris is endemic to Eurasia (including 11 species), and three species (Quercus acutissima, Quercus chenii and Quercus variabilis) are widely distributed in China. Here, we sequenced the complete plastid genomes of Q. acutissima and Q. chenii by Illumina pair-end sequencing, and obtained an additional plastome of Q. variabilis from GenBank. Although geographically distant...

Hexangulaconulariids (Cambrian stages 1‒2) are an extinct group of medusozoan polyps having a biradially symmetrical, fan-shaped periderm that is distinct from those of medusozoan polyps showing three-, four-, five-, or six-fold radial symmetry. Hexangulaconulariids exhibit substantial variation in gross morphology, including variation in the number of faces on each of the two major sides of the periderm. An intermediate taxon of hexangulaconulariids with ten faces (five on each major side) was expected. Here we describe...

We investigated the potential mechanism of the SR in maintenance of calcium (Ca2+) homeostasis of slow-twitch muscle (soleus, SOL), fast-twitch muscle (extensor digitorum longus, EDL) and mixed muscle (gastrocnemius, GAS) in hibernating ground squirrels (Spermophilus dauricus). Results showed that cytosolic and SR Ca2+ concentrations in distinct skeletal muscle fibers increased and decreased during late torpor, respectively, but both returned to summer-active levels during early torpor. Ryanodine receptor1 (RyR1) and sarco/endoplasmic reticulum Ca2+ ATPase isoform 1...

Ordovician (Darriwilian to Sandbian) micromorphic linguliform lingulate brachiopods are described from the Guniutan Formation at the Fenxiang section in Hubei province, and the Maocaopu and Cili sections in Hunan province of south-central China, situated on the Yangtze Platform. A total of 7560 specimens from 155 limestone samples (within the interval of Lenodus variabilis – Pygodus anserinus biozones) are assigned to 22 species, representing a low taxonomic diversity and low abundance fauna. The fauna is dominated...

Abundant articulated specimens of the oryctocarine trilobite Oryctocarella duyunensis from the lower Cambrian (Stage 4, Series 2) Balang Formation at the Bulin section in western Hunan Province, South China, permit the description of all meraspid degrees. The maximum number of thoracic segments observed in this collection is 11. Meraspid growth was accompanied by progressive and gradual change in overall form, and this animal showed an homonomously segmented trunk with variation in the number of pygidial...

Identifying competitive exclusion at the macroevolutionary scale has typically relied on demonstrating a reciprocal, contradictory response by two co-occurring, functionally similar clades. Finding definitive examples of such a response in fossil time-series has proven challenging however, as has controlling for the effects of a changing physical environment. We take a novel approach to this issue by quantifying variation in trait values that capture almost the entirety of function for steam locomotives (SL), a known example...

Soil microbes ultimately drive the mineralization of soil organic carbon and thus ecosystem functions. We compiled a dataset of the seasonality of microbial biomass carbon (MBC) and developed a semi-mechanistic model to map monthly MBC across the globe. MBC exhibits an equatorially symmetric seasonality between the Northern and Southern Hemispheres. In the Northern Hemisphere, MBC peaks in autumn and is minimal in spring at low latitudes (<25° N), peaks in the spring and is minimal...

Sections at Aşağiyaylabel and Yukariyaylabel, Taurus Mountains, southern Turkey, provide a rare opportunity to investigate conodont faunas in detail across a reef to slope transition. Intensive sampling of limestone beds (wackestones to packstones) through approximately 3 m at these locations has led to the recognition of a new lower Carnian (Julian 1/2) conodont fauna within the Kartoz and Kasimlar formations. Members of the subfamilies Paragondolellinae and Pseudofurnishiinae are recognized. The genus Kraussodontus is reported for...

Chaetognaths (arrow-worms) are enigmatic in terms of their phylogenetic position, while the existence of Protosagitta spinosa from the Chengjiang Lagerstätte suggests minimal change in their unique bodyplan since at least the early Cambrian. Apart from rare (and sometimes controversial) soft-bodied remains, the fossil record of chaetognaths is otherwise almost entirely dependent on early Palaeozoic phosphatic microfossils, some of which are placed amongst so-called protoconodonts. Fused spine clusters are strikingly similar to the cephalic grasping apparatus...

The Ediacaran to Cambrian transition is a critical interval of time during which major evolutionary changes occurred. Recently, abundant Protoconites minor have been recovered from the silty shales of the lower Cambrian Yanjiahe Formation (Terreneuvian, Fortunian – Stage 2) in the Three Gorges area of South China. These fossils represent an important ecological diversification of macroscopic organisms at the onset of the Cambrian. Protoconites minor is a probable cnidarian-grade organism preserved by carbon compression. Herein,...

Acrotretides are extinct micromorphic brachiopods that exhibited considerable morphological variation during their rapid evolution in the early Palaeozoic. The plano-conical shells of acrotretides are distinct in comparison to other brachiopod groups and despite their diversity and abundance in early Palaeozoic communities, their origins, early evolution, life history and phylogeny are poorly understood. Here, we employ advanced geometric morphometrics to quantitatively investigate ontogenetic variation and allometry in the ventral valve of the oldest known acrotretide species...

Primitive cnidarians are crucial for elucidating the early evolution of metazoan body plans and life histories in the late Neoproterozoic and Palaeozoic. The highest complexity of both evolutionary aspects within cnidarians is found in extant hydrozoans. Many colonial hydrozoans coated with chitinous exoskeletons have the potential to form fossils; however, only a few fossils possibly representing hydroids have been reported, which still require scrutiny. Here, we present an exceptionally well-preserved hydroid found in the Upper...

Environmental changes could dramatically influence the distribution area and niche of organisms. Taihang Mountains contain numerous endemic species, regarded as a center of distribution and diversity for many plant genera. It is necessary that having more comprehensive studies of test climate effects on species in this area. Opisthopappus (containing two species Opisthopappus taihangensis and Opisthopappus longilobus) is an endangered and endemic genus in the Taihang Mountains. Predicting the suitable potential distribution, exploring the niche difference...

Bryozoans (ectoprocts or moss animals) are aquatic, dominantly sessile, filter-feeding lophophorates that construct an organic or calcareous modular colonial (clonal) exoskeleton. The presence of six major orders of bryozoans with advanced polymorphisms in lower Ordovician rocks strongly suggests a Cambrian origin for the largest and most diverse lophophorate phylum. However, a lack of convincing bryozoan fossils from the Cambrian has hampered resolution of the true origins and character assembly of earliest members of the group....

Allopatric divergence is often initiated by geological uplift and restriction to sky-islands, climate oscillations, or river capture. However, it can be difficult to establish which mechanism was the most likely to generate the current phylogeographic structure of a species. Recently, genomic data in conjunction with a model testing framework have been applied to address this issue in animals. To test whether such an approach is also likely to be successful in plants we used population...

1. Homeostatic responses of animals to environmentally-induced changes in nutrient requirements provide a powerful basis for predictive ecological models, and yet such responses are virtually unstudied in the wild. 2. We tested for macronutrient-specific compensatory feeding responses by free-ranging golden snub-nosed monkeys (Rhinopithecus roxellana) inhabiting high altitude temperate forests where they experience a substantial difference in ambient temperature in cold winters vs. warmer springs. The monkeys had free access to natural foods throughout the year,...

1. Apposite conceptualization and measurement of resource variation is critical for understanding many issues in ecology, including ecological niches, persistence and distribution of populations, the structure of communities, and population resilience to perturbations. 2. We apply the nutritional geometry framework to conceptualise and quantify the responses of a temperate-living primate, the golden snub-nosed monkey (Rhinopithecus roxellana) to variation in resource quality and quantity and in nutrient requirements associated with seasonal environments. 3. We present a...

Diverse and abundant fossil taxa have been described in the lower Cambrian Shipai Formation in the Three Gorges area of Hubei province, South China, but the diversity of the co-occurring brachiopod fauna and their taxonomy is still far from clear. Here we describe the brachiopod fauna recovered from the Shipai Formation in the Three Gorges area of South China, including representatives of the subphylum Linguliformea: linguloids(Lingulellotreta ergalievi, Eoobolus malongensis and Neobolidae gen. indet. sp. indet.),...

Knowledge of interspecific divergence and population expansions/contractions of dominant forest trees in response to geological events and climatic oscillations is of major importance to understand their evolution and demography. However, the interspecific patterns of genetic differentiation and spatiotemporal population dynamics of three deciduous Cerris oak species (Q. acutissima, Q. variabilis and Q. chenii) that are widely distributed in China remain poorly understood. In this study, we genotyped 16 nuclear loci in 759 individuals sampled from...

The Ediacaran–Cambrian transition and the following Cambrian Explosion are among the most fundamental events in the evolutionary history of animals. Understanding these events is enhanced when phylogenetic linkages can be established among animal fossils across this interval and their trait evolution monitored. Doing this is challenging because the fossil record of animal lineages that span this transition is sparse, preserved morphologies generally simple, and lifestyles in the Ediacaran and Cambrian quite different. Here we identify...

Knowledge of primate evolutionary history from the Late Miocene to the present in East Asia is necessary to develop a tangible conservation strategy for their today and future. This background is especially evident from the distributions of fossil-bearing sites in the Pleistocene and historical records over the past 800 years. They illustrate catarrhines’ early dispersal and radiation routes, paths, and later shrinking trajectories, based on which their future distribution areas can be predicted, providing robust...

Research is a highly competitive profession where evaluation plays a central role; journals are ranked and individuals are evaluated based on their publication number, the number of times they are cited, and their h-index. Yet, such evaluations are often done in inappropriate ways that are damaging to individual careers, particularly for young scholars, and to the profession. Furthermore, as with all indices, people can play games to better their scores. This has resulted in the...

Octapyrgites elongatus n. gen. n. sp., a relatively rare, tetraradial olivooid (Cnidaria, Medusozoa), is described from Bed 5 of the Yanjiahe Formation (Cambrian Stage 2) near Yichang, China. Though similar to Olivooides and Quadrapyrgites from the Fortunian Stage in consisting of a partially corrugated (long.) periderm with a quadrate (transv.) apical portion and V-shaped apertural lobes, O. elongatus is substantially larger than other olivooids. The elongate apical region of O. elongatus is similar to four-sided...