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1.
Microscopy (Oxf) ; 2024 May 04.
Article in English | MEDLINE | ID: mdl-38702889

ABSTRACT

We investigate a one-dimensional plasmonic crystal (1D PlC) using momentum-resolved electron energy loss spectroscopy (EELS) and cathodoluminescence (CL) techniques, which are complementary in terms of available optical information. The PlC sample is fabricated from large aluminum grains through the focused ion beam (FIB) method. This approach allows curving nanostructures with high crystallinity, providing platforms for detailed analysis of plasmonic nanostructures using both EELS and CL. The momentum-resolved EELS visualizes dispersion curves outside the light cone, confirming the existence of the surface plasmon polaritons (SPP) and local modes, while the momentum-resolved CL mapping analysis identified these SPP and local modes. Such synergetic approach of two electron-beam techniques offers full insights into both radiative and non-radiative optical properties in plasmonic or photonic structures.

2.
Sci Rep ; 13(1): 13842, 2023 09 07.
Article in English | MEDLINE | ID: mdl-37679444

ABSTRACT

Ornithomimosauria consists of the ostrich-mimic dinosaurs, most of which showing cursorial adaptations, that often exhibit features indicative of herbivory. Recent discoveries have greatly improved our knowledge of their evolutionary history, including the divergence into Ornithomimidae and Deinocheiridae in the Early Cretaceous, but the early part of their history remains obscured because their fossil remains are scarce in the Aptian-Albian sediments. In recent years, many isolated ornithomimosaur remains have been recovered from the Aptian Kitadani Formation of Fukui, central Japan. These remains represent multiple individuals that share some morphological features common to them but unknown in other ornithomimosaurs, suggesting a monospecific accumulation of a new taxon. As a result of the description and phylogenetic analysis, the Kitadani ornithomimosaur is recovered as a new genus and species Tyrannomimus fukuiensis, the earliest definitive deinocheirid that complements our knowledge to understand the early evolutionary history of Ornithomimosauria. Due to its osteological similarity to Tyrannomimus, a taxon previously considered an early tyrannosauroid based on fragmentary specimens, namely Aviatyrannis jurassica, may represent the earliest ornithomimosaur from the Upper Jurassic of Europe, significantly expanding the temporal and biogeographic range of Ornithomimosauria. This finding fills a 20-million-year ghost lineage of Ornithomimosauria implied by the presence of the oldest fossil record of Maniraptora from the Middle Jurassic and is consistent with the hypothesis that their biogeographic range was widespread before the Pangaean breakup in the Kimmeridgian.


Subject(s)
Dinosaurs , Animals , Japan , Phylogeny , Acclimatization , Erythrocyte Membrane
4.
PeerJ ; 9: e11957, 2021.
Article in English | MEDLINE | ID: mdl-34484987

ABSTRACT

Brachiosauridae is a lineage of titanosauriform sauropods that includes some of the most iconic non-avian dinosaurs. Undisputed brachiosaurid fossils are known from the Late Jurassic through the Early Cretaceous of North America, Africa, and Europe, but proposed occurrences outside this range have proven controversial. Despite occasional suggestions that brachiosaurids dispersed into Asia, to date no fossils have provided convincing evidence for a pan-Laurasian distribution for the clade, and the failure to discover brachiosaurid fossils in the well-sampled sauropod-bearing horizons of the Early Cretaceous of Asia has been taken to evidence their genuine absence from the continent. Here we report on an isolated sauropod maxilla from the middle Cretaceous (Albian-Cenomanian) Longjing Formation of the Yanji basin of northeast China. Although the specimen preserves limited morphological information, it exhibits axially twisted dentition, a shared derived trait otherwise known only in brachiosaurids. Referral of the specimen to the Brachiosauridae receives support from phylogenetic analysis under both equal and implied weights parsimony, providing the most convincing evidence to date that brachiosaurids dispersed into Asia at some point in their evolutionary history. Inclusion in our phylogenetic analyses of an isolated sauropod dentary from the same site, for which an association with the maxilla is possible but uncertain, does not substantively alter these results. We consider several paleobiogeographic scenarios that could account for the occurrence of a middle Cretaceous Asian brachiosaurid, including dispersal from either North America or Europe during the Early Cretaceous. The identification of a brachiosaurid in the Longshan fauna, and the paleobiogeographic histories that could account for its presence there, are hypotheses that can be tested with continued study and excavation of fossils from the Longjing Formation.

5.
Commun Biol ; 2: 399, 2019.
Article in English | MEDLINE | ID: mdl-31754639

ABSTRACT

The Early Cretaceous basal birds were known largely from just two-dimensionally preserved specimens from north-eastern China (Jehol Biota), which has hindered our understanding of the early evolution of birds. Here, we present a three-dimensionally-preserved skeleton (FPDM-V-9769) of a basal bird from the Early Cretaceous of Fukui, central Japan. Unique features in the pygostyle and humerus allow the assignment of FPDM-V-9769 to a new taxon, Fukuipteryx prima. FPDM-V-9769 exhibits a set of features comparable to that of other basalmost birds including Archaeopteryx. Osteohistological analyses indicate that FPDM-V-9769 is subadult. Phylogenetic analyses resolve F. prima as a non-ornithothoracine avialan basal to Jeholornis and outgroup of the Pygostylia. This phylogenetic result may imply a complex evolutionary history of basal birds. To our knowledge, FPDM-V-9769 represents the first record of the Early Cretaceous non-ornithothoracine avialan outside of the Jehol Biota and increases our understanding of their diversity and distribution during the time.


Subject(s)
Biological Evolution , Birds/anatomy & histology , Birds/classification , Fossils , Paleontology , Animals , Histocytochemistry , Japan , Phylogeny , X-Ray Microtomography
6.
PLoS One ; 14(10): e0222489, 2019.
Article in English | MEDLINE | ID: mdl-31596853

ABSTRACT

The isolated fossil remains of an allosauroid theropod from the Lower Cretaceous Khok Kruat Formation of Khorat, Thailand, are described in this study. Detailed observations support the establishment of a new allosauroid, Siamraptor suwati gen. et sp. nov. This new taxon is based on a composite cranial and postcranial skeleton comprising premaxilla, maxilla, jugal, surangular, prearticular, articular, vertebrae, manual ungual, ischium, tibia, and pedal phalanx. It is distinguished from other allosauroids by characters such as a jugal with straight ventral margin and dorsoventrally deep anterior process below the orbit, a surangular with a deep oval concavity at the posterior end of the lateral shelf and four posterior surangular foramina, a long and narrow groove along the suture between the surangular and the prearticular, an articular with a foramen at the notch of the suture with the prearticular, an anterior cervical vertebra with a pneumatic foramen (so-called 'pleurocoel') excavating parapophysis, and cervical and posterior dorsal vertebrae penetrated by a pair of small foramina bilaterally at the base of the neural spine. The presence of a huge number of camerae and pneumatopores in cranial and axial elements reveals a remarkable skeletal pneumatic system in this new taxon. Moreover, the phylogenetic analyses revealed that Siamraptor is a basal taxon of Carcharodontosauria, involving a new sight of the paleobiogeographical context of this group. Siamraptor is the best preserved carcharodontosaurian theropod in Southeast Asia, and it sheds new light on the early evolutionary history of Carcharodontosauria.


Subject(s)
Dinosaurs/anatomy & histology , Animals , Bone and Bones/anatomy & histology , Dinosaurs/classification , Fossils , Geography , Phylogeny , Thailand , Time Factors
7.
Microsc Res Tech ; 80(8): 959-968, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28485485

ABSTRACT

Plant anatomy was examined for two clarinet reeds made out of Arundo donax by different means of microscopy: light microscopy, low-energy secondary electron scanning electron microscopy (SEM), backscattered electron SEM, and helium ion microscopy (HiM). The local indentation hardness HIT and Young's modulus EIT of different tissues on their cross sections were measured. A vascular bundle (Vb) (HIT = 60-100 MPa, EIT = 1,500-2,000 MPa) that includes soft tissues of phloem and xylem and a vascular bundle sheath (Bs) (HIT = 300-500 MPa, EIT = ∼7,000 MPa) form a pipe of the strong string along the longitudinal direction of the cane. This Vb/Bs string is connected transversally with a net of thin cell-walls of parenchyma cells (Pa) (HIT = 70-200 MPa, EIT = 2,000-3,000 MPa) that also range along the longitudinal direction of the cane. It was turned out that the acoustic quality of a reed is mainly ascribed to the shape and configuration of Vb and the size of Pa. A reed where Vb bundles with continuous Bs rings are homogeneously distributed with higher proportion among a softer network of small Pa cells enables musical performance.

8.
Curr Protoc Cytom ; 80: 12.45.1-12.45.15, 2017 Apr 03.
Article in English | MEDLINE | ID: mdl-28369763

ABSTRACT

The ability to correlate fluorescence microscopy (FM) and electron microscopy (EM) data obtained on biological (cell and tissue) specimens is essential to bridge the resolution gap between the data obtained by these different imaging techniques. In the past such correlations were limited to either EM navigation in two dimensions to the locations previously highlighted by fluorescence markers, or subsequent high-resolution acquisition of tomographic information using a TEM. We present a novel approach whereby a sample previously investigated by FM is embedded and subjected to sequential mechanical polishing and backscatter imaging by scanning electron microscope. The resulting three dimensional EM tomogram of the sample can be directly correlated to the FM data. © 2017 by John Wiley & Sons, Inc.


Subject(s)
Imaging, Three-Dimensional , Microscopy, Electron, Scanning/methods , Microscopy, Fluorescence/methods , HeLa Cells , Humans , Kidney/ultrastructure
9.
Sci Rep ; 6: 20478, 2016 Feb 23.
Article in English | MEDLINE | ID: mdl-26908367

ABSTRACT

Our understanding of coelurosaurian evolution, particularly of bird origins, has been greatly improved, mainly due to numerous recently discovered fossils worldwide. Nearly all these discoveries are referable to the previously known coelurosaurian subgroups. Here, we report a new theropod, Fukuivenator paradoxus, gen. et sp. nov., based on a nearly complete specimen from the Lower Cretaceous Kitadani Formation of the Tetori Group, Fukui, Japan. While Fukuivenator possesses a large number of morphological features unknown in any other theropod, it has a combination of primitive and derived features seen in different theropod subgroups, notably dromaeosaurid dinosaurs. Computed-tomography data indicate that Fukuivenator possesses inner ears whose morphology is intermediate between those of birds and non-avian dinosaurs. Our phylogenetic analysis recovers Fukuivenator as a basally branching maniraptoran theropod, yet is unable to refer it to any known coelurosaurian subgroups. The discovery of Fukuivenator considerably increases the morphological disparity of coelurosaurian dinosaurs and highlights the high levels of homoplasy in coelurosaurian evolution.


Subject(s)
Dinosaurs/anatomy & histology , Animals , Biological Evolution , Ear, Inner/anatomy & histology , Extremities/anatomy & histology , Fossils , Japan , Phylogeny , Skull/anatomy & histology , Spine/anatomy & histology , Tooth/anatomy & histology
10.
PLoS One ; 10(12): e0145904, 2015.
Article in English | MEDLINE | ID: mdl-26716981

ABSTRACT

A new basal hadrosauroid dinosaur from the Lower Cretaceous Khok Kruat Formation of Thailand, Sirindhorna khoratensis gen. et sp. nov is described. The new taxon is based on composite skull and mandible including premaxilla, maxilla, jugal, quadrate, braincases, predentary, dentaries, surangular, and maxillary and dentary teeth. It is diagnostic by such characters as, sagittal crest extending along entire dorsal surface of the parietal and reaching the frontoparietal suture (autapomorphy), transversely straight frontoparietal suture, caudodorsally faced supraoccipital, no participation of the supraoccipital in the foramen magnum, mesiodistally wide leaf-shaped dentary tooth with primary and secondary ridges on the lingual surface of the crown, perpendicularly-erected and large coronoid process of dentary, and nonvisible antorbital fossa of the maxilla in lateral view. Phylogenetic analysis revealed S. khoratensis as among the most basal hadrosauroids. Sirindhorna khoratensis is the best-preserved iguanodontian ornithopod in Southeast Asia and sheds new light to resolve the evolution of basal hadrosauriforms.


Subject(s)
Dinosaurs , Animals , Biological Evolution , Dinosaurs/anatomy & histology , Dinosaurs/classification , Fossils/anatomy & histology , Mandible/anatomy & histology , Maxilla/anatomy & histology , Phylogeny , Skull/anatomy & histology , Thailand , Tooth/anatomy & histology
11.
Zootaxa ; 3914(4): 421-40, 2015 Jan 29.
Article in English | MEDLINE | ID: mdl-25661952

ABSTRACT

A new basal hadrosauroid, Koshisaurus katsuyama, from the Lower Cretaceous Kitadani Formation in Fukui, central Japan, is reported. The new taxon is distinguished by an autapomorphy and a unique combination of maxillary, vertebral, pubic and femoral characters. A phylogenetic analysis indicates that Koshisaurus is positioned as a basal member of Hadrosauroidea and is more derived than the contemporaneous Fukuisaurus, which is a non-hadrosauroid hadrosauriform. The presence of the antorbital fossa on the maxilla and at least three subsidiary ridges on the labial side of maxillary tooth crown implies that Koshisaurus was among the most basal hadrosauroids. This discovery indicates a higher diversity of hadrosauroids along the eastern margin of the Asian continent in the Early Cretaceous. 


Subject(s)
Dinosaurs/classification , Animal Distribution , Animals , Body Size , Dinosaurs/anatomy & histology , Dinosaurs/genetics , Fossils/anatomy & histology , Japan , Organ Size , Phylogeny , Spine/anatomy & histology , Tooth/anatomy & histology
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