Dinosaur track assemblages from mid-Cretaceous of Fujian Province, southeastern China: ichnotaxonomic review and faunal comparison.

Among the the mid-Cretaceous strata in China, considerable dinosaur record are preserved in the southeastern mountainous and arc-related basins. The Shanghang Basin is one of the sporadic red-stratified basins distributed in western Fujian, SE China, and has previously been discovered as the home of an ornithopod-dominaited ichnofauna, which is also characterized by the large troodontid ichnogenera Fujianipus. Include the newly discovered fossils, further confirming that this tracksite is dominated by ornithopods, characterized by a significant proportion (>27%) of large ornithopods, with deinonychosaurians as the possible apex predators.

Deinonychosaur trackways in southeastern China record a possible giant troodontid.

The Longxiang tracksite (lower Upper Cretaceous, Shanghang Basin) includes twelve didactyl deinonychosaur tracks that fall into two morphologies, differentiated by both size and form. The smaller tracks (∼11 cm long) are referable to the ichnogenus . The larger tracks (∼36 cm long) establish the ichnotaxon .

Evidence for a mixed-age group in a pterosaur footprint assemblage from the early Upper Cretaceous of Korea.

Here we describe a new pterosaur footprint assemblage from the Hwasun Seoyuri tracksite in the Upper Cretaceous Jangdong Formation of the Neungju Basin in Korea. The assemblage consists of many randomly oriented prints in remarkably high densities but represents a single ichnotaxon, Pteraichnus. Individuals exhibit a large but continuous size range, some of which, with a wingspan estimated at 0.

Hadrosauroid eggs and embryos from the Upper Cretaceous (Maastrichtian) of Jiangxi Province, China.

Background: Dinosaur eggs containing embryos are rare, limiting our understanding of dinosaur development. Recently, a clutch of subspherical dinosaur eggs was discovered while blasting for a construction project in the Upper Cretaceous red beds (Hekou Formation) of the Ganzhou Basin, Jiangxi Province, China. At least two of the eggs contain identifiable hadrosauroid embryos, described here for the first time.

Facile synthesis of nanocellulose-based CuO/Ag heterostructure as a surface-enhanced Raman scattering substrate for trace dye detection.

Semiconductor metal-oxide/metal heterostructures with synergetic properties have potential applications in photocatalysis and optical sensors. Here, CuO sub-micro cubes were synthesized under environmentally benign conditions using 2, 2, 6, 6-tetramethylpyperdine-1-oxyl (TEMPO)-oxidized cellulose nanofibrils as a reducing and stabilizing agent. Then the surface of the CuO cubes was decorated with silver nanoparticles (AgNPs) by a substitution reaction.

An exquisitely preserved theropod dinosaur embryo sheds light on avian-like prehatching postures.

Despite the discovery of many dinosaur eggs and nests over the past 100 years, articulated embryos are remarkably rare. Here we report an exceptionally preserved, articulated oviraptorid embryo inside an elongatoolithid egg, from the Late Cretaceous Hekou Formation of southern China. The head lies ventral to the body, with the feet on either side, and the back curled along the blunt pole of the egg, in a posture previously unrecognized in a non-avian dinosaur, but reminiscent of a late-stage modern bird embryo.

Crab in amber reveals an early colonization of nonmarine environments during the Cretaceous.

Amber fossils provide snapshots of the anatomy, biology, and ecology of extinct organisms that are otherwise inaccessible. The best-known fossils in amber are terrestrial arthropods—principally insects—whereas aquatic organisms are rarely represented. Here, we present the first record of true crabs (Brachyura) in amber—from the Cretaceous of Myanmar [~100 to 99 million years (Ma)].

Lower cretaceous avian-dominated, theropod, thyreophoran, pterosaur and turtle track assemblages from the Tugulu Group, Xinjiang, China: ichnotaxonomy and palaeoecology.

Rich tetrapod ichnofaunas, known for more than a decade, from the Huangyangquan Reservoir (Wuerhe District, Karamay City, Xinjiang) have been an abundant source of some of the largest Lower Cretaceous track collections from China. They originate from inland lacustrine clastic exposures of the 581-877 m thick Tugulu Group, variously divided into four formations and subgroups in the northwestern margin of the Junggar Basin. The large Huangyangquan track assemblages occur in the Lower layer/Subgroup II.

Biodegradable cellulose I (II) nanofibrils/poly(vinyl alcohol) composite films with high mechanical properties, improved thermal stability and excellent transparency.

Cellulose nanofibrils (CNFs) with cellulose I and II allomorphs were efficiently prepared by sulfuric acid hydrolysis of eucalyptus cellulose under three different conditions followed by mechanical treatments: (i) classical sulfuric acid hydrolysis of cellulose I (CNF-I), (ii) sulfuric acid hydrolysis of mercerized cellulose II (MNF-II), and (iii) solubilization and hydrolysis of cellulose I by concentrated sulfuric acid and subsequent recrystallization in water (RNF-II). Crystal structure, surface chemistry, morphology and thermal properties of three CNFs were investigated and compared. Three CNFs of 2-10 wt% were mixed with PVA to prepare biodegradable composite films.

Retraction Note: Hummingbird-sized dinosaur from the Cretaceous period of Myanmar.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Hummingbird-sized dinosaur from the Cretaceous period of Myanmar.

Skeletal inclusions in approximately 99-million-year-old amber from northern Myanmar provide unprecedented insights into the soft tissue and skeletal anatomy of minute fauna, which are not typically preserved in other depositional environments. Among a diversity of vertebrates, seven specimens that preserve the skeletal remains of enantiornithine birds have previously been described, all of which (including at least one seemingly mature specimen) are smaller than specimens recovered from lithic materials. Here we describe an exceptionally well-preserved and diminutive bird-like skull that documents a new species, which we name Oculudentavis khaungraae gen.

Transition of cellulose supramolecular structure during concentrated acid treatment and its implication for cellulose nanocrystal yield.

Cellulose nanocrystals with cellulose I and II allomorphs (CNC-I and CNC-II) were prepared from eucalyptus cellulose I substrate by controlling the sulfuric acid hydrolysis conditions, including acid concentration (56-64 wt%), reaction temperature (45 or 60 °C) and time (10-120 min). The crystalline structures were verified by XRD and C-NMR. CNC-II only appeared at very restricted reaction conditions.

A mid-Cretaceous enantiornithine foot and tail feather preserved in Burmese amber.

Since the first skeletal remains of avians preserved in amber were described in 2016, new avian remains trapped in Cretaceous-age Burmese amber continue to be uncovered, revealing a diversity of skeletal and feather morphologies observed nowhere else in the Mesozoic fossil record. Here we describe a foot with digital proportions unlike any previously described enantiornithine or Mesozoic bird. No bones are preserved in the new specimen but the outline of the foot is recorded in a detailed skin surface, which is surrounded by feather inclusions including a partial rachis-dominated feather.

Land Snail with Periostracal Hairs Preserved in Burmese Amber.

Excellently preserved fossils often provide important insights into evolutionary histories and adaptations to environmental change in Earth's biogeologic record. Mid-Cretaceous Burmese amber, for example, is a proven reservoir for spectacular findings. Here we document the first record of a fossil land snail with periostracal hairs preserved in amber.

A New Enantiornithine Bird with Unusual Pedal Proportions Found in Amber.

Recent discoveries of vertebrate remains trapped in middle Cretaceous amber from northern Myanmar [1, 2] have provided insights into the morphology of soft-tissue structures in extinct animals [3-7], in particular, into the evolution and paleobiology of early birds [4, 8, 9]. So far, five bird specimens have been described from Burmese amber: two isolated wings, an isolated foot with wing fragment, and two partial skeletons [4, 8-10]. Most of these specimens contain the remains of juvenile enantiornithine birds [4].

Author Correction: Exquisitely-preserved, high-definition skin traces in diminutive theropod tracks from the Cretaceous of Korea.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Inter-amphibian predation in the Early Cretaceous of China.

For most fossil taxa, dietary inference relies primarily on indirect evidence from jaw morphology and the dentition. In rare cases, however, preserved gut contents provide direct evidence of feeding strategy and species interaction. This is important in the reconstruction of food webs and energy flow through ancient ecosystems.

Exquisitely-preserved, high-definition skin traces in diminutive theropod tracks from the Cretaceous of Korea.

Small theropod tracks, ichnogenus Minisauripus, from the Jinju Formation (Cretaceous) of Korea reveal exquisitely preserved skin texture impressions. This is the first report for any dinosaur of skin traces that cover entire footprints, and every footprint in a trackway. Special sedimentological conditions allowed footprint registration without smearing of skin texture patterns which consist of densely-packed, reticulate arrays of small (<0.

A fully feathered enantiornithine foot and wing fragment preserved in mid-Cretaceous Burmese amber.

Over the last three years, Burmese amber (~99 Ma, from Myanmar) has provided a series of immature enantiornithine skeletal remains preserved in varying developmental stages and degrees of completeness. These specimens have improved our knowledge based on compression fossils in Cretaceous sedimentary rocks, adding details of three-dimensional structure and soft tissues that are rarely preserved elsewhere. Here we describe a remarkably well-preserved foot, accompanied by part of the wing plumage.

Smallest known raptor tracks suggest microraptorine activity in lakeshore setting.

Ongoing studies of a multiple track-bearing horizons from massive excavations in the Jinju Formation (Lower Cretaceous) of South Korea have yielded a remarkable diversity of avian, non-avian dinosaur, pterosaur, crocodilian and mammal tracks, many very small and well preserved. Here we report diminutive, didactyl tracks (~1.0 cm long) assigned to a new dromaeosaurid ichnogenus Dromaeosauriformipes, which resembles the larger, but still quite small, ichnogenus Dromaeosauripus, also from the same formation only 30 km away.

A mid-Cretaceous embryonic-to-neonate snake in amber from Myanmar.

We present the first known fossilized snake embryo/neonate preserved in early Late Cretaceous (Early Cenomanian) amber from Myanmar, which at the time, was an island arc including terranes from Austral Gondwana. This unique and very tiny snake fossil is an articulated postcranial skeleton, which includes posterior precloacal, cloacal, and caudal vertebrae, and details of squamation and body shape; a second specimen preserves a fragment of shed skin interpreted as a snake. Important details of skeletal ontogeny, including the stage at which snake zygosphene-zygantral joints began to form along with the neural arch lamina, are preserved.

The earliest direct evidence of frogs in wet tropical forests from Cretaceous Burmese amber.

Frogs are a familiar and diverse component of tropical forests around the world. Yet there is little direct evidence from the fossil record for the antiquity of this association. We describe four fossil frog specimens from mid-Cretaceous (~99 mya) amber deposits from Kachin State, Myanmar for which the associated fauna provides rich paleoenvironmental context.