Feather Shape Research Articles

Functional constraints on the number and shape of flight feathers

As a fundamental ecological aspect of most organisms, locomotor function significantly constrains morphology. At the same time, the evolution of novel locomotor abilities has produced dramatic morphological transformations, initiating some of the most significant diversifications in life history. Despite significant new fossil evidence, it remains unclear whether volant locomotion had a single or multiple origins in pennaraptoran dinosaurs and the volant abilities of individual taxa are controversial. The evolution of powered flight in modern birds involved exaptation of feathered surfaces extending off the limbs and tail yet most studies concerning flight potential in pennaraptorans do not account for the structure and morphology of the wing feathers themselves. Analysis of the number and shape of remex and rectrix feathers across a large dataset of extant birds indicates that the number of remiges and rectrices and the degree of primary vane asymmetry strongly correlate with locomotor ability revealing important functional constraints. Among these traits, phenotypic flexibility varies reflected by the different rates at which morphological changes evolve, such that some traits reflect the ancestral condition, whereas others reflect current locomotor function. While Mesozoic birds and Microraptor have remex morphologies consistent with extant volant birds, that of anchiornithines deviate significantly providing strong evidence this clade was not volant. The results of these analyses support a single origin of dinosaurian flight and indicate the early stages of feathered wing evolution are not sampled by the currently available fossil record.

Genetic Nature of Fertility Type in Cotton Hybrids

Studies have been conducted to evaluate the genetic potential of cotton species and to develop disease and pest resistant cotton varieties from them. The significance of the level of leaf hairiness in the representatives of the Gossypium L. family in tolerance to sucking pests, spider mite, aphid, was studied. Resources were obtained to measure or qualitatively assess leaf hairiness, transfer the hairiness marker for pest tolerance into the genome of G. hirsutum L., and create cultivars with a combination of tolerance and economic traits. In the C2 plants of the combinations obtained by cross-breeding the wild-type ridges with twisting hairiness with the analyzer L-001 line, separation of the hairiness character was noted, its ratio was 3:1 according to the phenotype (1:2:1 according to the genotype). This separation in second-generation hybrids indicates that the feather shape trait is monogenic in nature.

Morphometric Analysis for Sustainable River Management: A Case Study of Ciujung Watershed, Banten, Indonesia

Ciujung watershed is located in Banten province, Indonesia. The Ciujung watershed is one of the watersheds that have a significant area coverage, such as Serang, Lebak, and the eastern part of Pandeglang. These areas are developing both in terms of population growth and infrastructure. Therefore, a more in-depth study of the Ciujung watershed, namely morphometric studies, is needed to optimize the utilization of the river's renewable natural resources and mitigate potential flood hazards in the watershed area. The method used is remote sensing based on DEMNAS satellite data using QGis software. The parameters analyzed were watershed shape, watershed area, river branch ratio, and river density. The results show that the Ciujung watershed is divided into 14 sub-watersheds. In general, the sub-watersheds have a bird feather shape, and some are radial and parallel, which causes some research areas to be very at risk of flooding. From the condition of river branching, most areas are unaffected by deformation. A small part of the deformed area occurs in the middle area of the Ciujung watershed. This is interpreted to be related to tectonic activity. The drainage density shows that the Ciujung watershed is based on resistant rocks and materials, so it is easily eroded and causes siltation of the river in the downstream area, which can trigger flooding.

Transcriptome analysis reveals the genetic basis of crest cushion formation in duck1

The Chinese crested duck is a unique duck breed having a bulbous feather shape on its duck head. However, the mechanisms involved in its formation and development are unclear. In the present study, RNA sequencing analysis was performed on the crested tissues of six Chinese crested ducks and the scalp tissues of six cherry valley ducks (CVs) from two developmental stages. This study identified 261 differentially expressed genes (DEGs), 122 upregulated and 139 downregulated, in the E28 stage and 361 DEGs, 154 upregulated and 207 downregulated in the D42 stage between CC and CV ducks. The subsequent results of weighted gene co-expression network analysis (WGCNA) revealed that the turquoise and cyan modules were associated with the crest trait in the D42 stage, meanwhile, the green, brown, and pink modules were associated with the crest trait in the E28 stage. Venn analysis of the DEGs and WGCNA showed that 145 and 45 genes are associated between the D42 and E28 stages, respectively. The expression of WNT16, BMP2, SLC35F2, SLC6A15, APOBEC2, ABHD6, TNNC2, MYL1, and TNNI2 were verified by real-time quantitative polymerase chain reaction. This study provides an approach to reveal the molecular mechanisms underlying the crested trait development.

Fracture Characteristics of Commercial PEEK Dental Crowns: Combining the Effects of Aging Time and TiO2 Content.

Polyetheretherketone (PEEK) is an emerging thermoplastic polymer with good mechanical properties and an elastic modulus similar to that of alveolar bone. PEEK dental prostheses for computer-aided design/computer-aided manufacturing (CAD/CAM) systems on the market often have additives of titanium dioxide (TiO2) to strengthen their mechanical properties. However, the effects of combining aging, simulating a long-term intraoral environment, and TiO2 content on the fracture characteristics of PEEK dental prostheses have rarely been investigated. In this study, two types of commercially available PEEK blocks, containing 20% and 30% TiO2, were used to fabricate dental crowns by CAD/CAM systems and were aged for 5 and 10 h based on the ISO 13356 specifications. The compressive fracture load values of PEEK dental crowns were measured using a universal test machine. The morphology and crystallinity of the fracture surface were analyzed by scanning electron microscopy and an X-ray diffractometer, respectively. Statistical analysis was performed using the paired t-test (α = 0.05). Results showed no significant difference in the fracture load value of the test PEEK crowns with 20% and 30% TiO2 after 5 or 10 h of aging treatment; all test PEEK crowns have satisfactory fracture properties for clinical applications. Fracture surface analysis revealed that all test crowns fractured from the lingual side of the occlusal surface, with the fracture extending along the lingual sulcus to the lingual edge, showing a feather shape at the middle part of the fracture extension path and a coral shape at the end of the fracture. Crystalline analysis showed that PEEK crowns, regardless of aging time and TiO2 content, remained predominantly PEEK matrix and rutile phase TiO2. We would conclude that adding 20% or 30% TiO2 to PEEK crowns may have been sufficient to improve the fracture properties of PEEK crowns after 5 or 10 h of aging. Aging times below 10 h may still be safe for reducing the fracture properties of TiO2-containing PEEK crowns.

Twinned dendrites growth in wire arc directed energy deposition of Al-Zn-Mg-Cu alloy

Twinned dendrites have attracted worldwide attention in the past half century due to their unusual orientation and crystallographic symmetry. Successive research has established a basic understanding of them in relatively steady processes like direct chill casting and directional solidification. This work, for the first time, investigated the growth behaviors of twinned dendrites in the wire arc directed energy deposition. The crystallographic characteristics, formation, and evolution laws of the twinned dendrites in the unsteady localized solidification condition are explored via experiments and numerical simulations. Results show that stacking faults are vital in the longitudinal growth of twinned dendrites by adjusting intermittent twin boundaries. During deposition, Mg, Zn, and Cu, which have low stacking fault energy, can promote the growth of twinned dendrites. The molten pool tail has large temperature gradients, crystallization velocities, and sufficient convection, providing advantageous growth conditions for twinned dendrites. Competitive relationships form between twinned and regular dendrites at the molten pool center. However, the twinned dendrites also cooperate with regular dendrites in epitaxial growth via their 〈100〉 lateral branch. With the remelting depth increasing, the twinned dendrite morphology changes from lamellar to isolated unilateral feather shape, then to unchained islands, and finally disappear.

Functionalized bentonite for removal of Pb(II) and As(V) from surface water: Predicting capability and mechanism using artificial neural network

An efficient material is required to develop effective removal systems with high flexibility and low cost for capturing toxic ions. In this study, a synthesized lanthanum oxide-modified bentonite (B-La) adsorbent was used for the adsorption of As(V) and Pb(II). The prepared material, B-La, shows a feather shape surface with a 25 nm average particle size and was also confirmed by SEM and TEM. Texture and chemical composition confirmed by XRD and FTIR. From the XPS investigation, the underlying mechanism for Pb(II) and As(V) removal was investigated, and the production of B-La-As(V) and B-La-Pb(II) inner-sphere complexation was shown to be the dominating pathway. As per the pH effect studies, it was observed that B-La efficiently adsorbed Pb(II) and As(V) over a pH range of 6.0. Pb(II) adsorption was not substantially impacted by ionic strength or coexisting ions; however, As(V) adsorption was influenced by phosphate and fluoride, showing that B-La has a strong affinity towards Pb(II) and As(V). A pseudo-second-order model could well fit Pb(II) and As(V) adsorption, and Langmuir equilibrium adsorption describes Pb(II) and As(V) adsorption. The adsorption capacity was 147.05 mg of Pb(II)/g and 156.26 mg of As(V)/g, reflected at the dosage of 0.2 g/L at 25 °C, pH 6.0. Using the response surface methodology, the optimum values for process parameters, such as initial concentration, temperature, pH, and time, for both Pb(II) and As(V) removal are identified. Desorption studies were also performed to confirm the presented B-La adsorbents' environmental suitability. The Pb(II) and As(V) were completely desorbed with 0.2 M HNO3 and 0.2 M NaOH; after washing with water, it is ready to reuse in the next cycle and can be reused in several cycles of Pb(II) and As(V) adsorption operations. The identified data-driven quadratic model strongly correlated with the experimental values. Machine-learning techniques like artificial neural networks (ANN) and adaptive neuro-fuzzy inference systems (ANFIS), based on results ANN predicted model shows high correlation R2 value for both metal ions. All the findings indicated that porous B-La was a promising material for Pb(II) and As(V) removal.

Influence of Aging on the Fracture Characteristics of Polyetheretherketone Dental Crowns: A Preliminary Study.

Although polyetheretherketone (PEEK) is becoming more widely used in dentistry applications, little is known about how aging will affect this material. Therefore, this study aimed to investigate the influence of an aging treatment on fracture characteristics of PEEK dental crowns. Additionally, the impact of the addition of titanium dioxide (TiO2) into PEEK was examined. Two types of commercial PEEK discs were used in this study, including TiO2-free and 20% TiO2-containing PEEK. The PEEK dental crowns were fabricated and aging-treated at 134 °C and 0.2 MPa for 5 h in accordance with the ISO 13356 specification before being cemented on artificial tooth abutments. The fracture loads of all crown samples were measured under compression tests. Results demonstrated that adding TiO2 enhanced the fracture load of PEEK crowns compared to TiO2-free PEEK crowns before the aging treatment. However, the aging treatment decreased the fracture load of TiO2-containing PEEK crowns while increasing the fracture load of TiO2-free PEEK crowns. The fracture morphology of TiO2-containing PEEK crowns revealed finer feather shapes than that of the TiO2-free PEEK crowns. We concluded that adding TiO2 increased the fracture load of PEEK crowns without aging treatment. Still, the aging treatment influenced the fracture load and microscopic fracture morphology of PEEK crowns, depending on the addition of TiO2.

Investigation on Erosion of Continuous Bending Pipes in Different Directions

With the increasing demand for natural gas in the world, ensuring the safety and stability of pipeline transportation of natural gas has become an important subject. Compared with the studies focused on the erosion of single bend, T-pipe, and U-pipe, the studies on the continuous bend in different directions are scarce. In this paper, the model is characterized by three straight pipes with the same length and directions along the Z, Y, and X axes of the Cartesian coordinate system. The numerical simulation of gas-solid two-phase flow under different gas to solid mass ratios in the continuous bent pipeline is carried out by selecting the Oka erosion model. The results indicate that the velocity distribution of the second bend is different from that of the first bend. With the change of flow deflection angle and the accumulation of the centrifugal force, the shape of the velocity contours in the second bend turns from “basin” into a comma and the velocity experiences a process including rapid increase, slow decrease, gradual increase, and steep decrease. When the flow rate is 12.5 m/s, the maximum speed of the second bend is about 5 % greater than that of the first bend. Instead of a “straight-line” shape in the erosion area of the first bend, the second presents a feather shape. As the flow rate increases gradually, the shape characteristics of the feather erosion zone change from short and dense to long and loose. Besides, the maximum erosion rate of the second bend is greater than that of the first even about 1.52 times. Finally, according to the simulation results, the protection suggestion of the continuous elbow is given.

Experimental investigation on tip-vortex flow characteristics of novel bionic multi-tip winglet configurations

Five bionic multi-tip winglet configurations, inspired by basic feather shapes and wingtip postures of birds, were designed to suppress the tip-vortex structures around their wingtips. Each of the bionic multi-tip winglet configurations consists of multiple novel feather-shaped winglets and looks like a dihedral (or non-planar) wingtip shape. The influence of the distribution density and chord-directional gap for the feather-shaped winglets on the tip-vortex flow characteristics was investigated experimentally at Re = 83 166. The results reveal that the vorticity levels of the tip-vortex structures in the near-wake region can achieve effective suppression by improving the feather-shaped winglets’ distribution density at the wingtip of the bionic wing configuration. The maximum proportions of the induced drag relative to the total drag for the bionic wing configurations I, II, and III are 25.54%, 21.05%, and 19.47%, respectively. The variation of the feather-shaped winglets’ distribution density significantly affects the lift–drag efficiency of the bionic wing configuration. However, the increase in the feather-shaped winglets’ mounting gap weakens the tip-vortex suppression effect for the bionic wing configuration (equipped with the three feather-shaped winglets) to some degree. The maximum proportions of the induced drag relative to the total drag for the bionic wing configurations IV and V are 27.28% and 28.32%, respectively. Compared with the bionic wing configuration I, the slightly worse aerodynamic performance for the bionic wing configurations IV or V (with the larger feather-shaped winglets’ mounting gap) is closely related to its weaker tip-vortex suppression ability.

Hydration-induced reversible deformation of biological materials

The influx and efflux of water in biological structures actuates reversible deformation and recovery processes that are crucial for mechanical functions in plants and animals. These processes utilize various mechanochemical mechanisms: swelling directed by the arrangement of cellulosic microfibrils in a bilayer construct, which generates different deformation patterns; lignification gradients; hierarchical foam-like inner structures, some of which also include swelling by hygroscopic cellulose inner cell layer; turgor pressure, which is activated by osmosis and acts at the cellular level, generating reversible motions. In this Review, we present representatives of each of these four mechanisms: pine cones, wheat awns, the twisted opening of Bauhinia pods and the seed of the stork’s bill; the resurrection plant; ice plant seed capsules and carrotwood seed pod; the wilting and redressing of plant stems. Natural polymeric materials produced by animals can also exhibit hydration-driven shape and strength recovery: bird feathers and hair are prime examples. Spider silk — a non-keratinous biopolymer — also exhibits humidity-driven reversible deformation. After describing these animal-based mechanisms, we outline bioinspired applications to actuate multifunctional and biocompatible smart materials, and indicate future directions of research with potential for new bioinspired designs. The influx and efflux of water in biological structures leads to reversible deformation, which has important functions in plants (for example, in seed protection and dispersal) and animals (for example, in the recovery of the strength and shape of feathers, and for reversible changes in silk and hair). Here the authors review the main hydration-induced deformation mechanisms and highlight applications inspired by these processes.

Flight, symmetry and barb angle evolution in the feathers of birds and other dinosaurs.

There has been much discussion over whether basal birds (e.g. Archaeopteryx and Confuciusornis) exhibited active flight. A recent study of barb angles has suggested they likely could not but instead may have exhibited a gliding phase. Pennaceous primary flight feathers were proposed to show significant shifts in barb angle values of relevance to the inference of flight in these extinct taxa. However, evolutionary trends in the evolution of these barb angle traits in extant volant taxa were not analysed in a phylogenetic frame. Neither the ancestral crown avian condition nor the condition in outgroup dinosaurs with symmetrical feathers were assessed. Here, we expand the fossil sample and reanalyse these data in a phylogenetic frame. We show that extant taxa, including strong flyers (e.g. some songbirds), show convergence on trailing barb angles and barb angle asymmetry observed in Mesozoic taxa that were proposed not to be active fliers. Trailing barb angles in these Mesozoic taxa are similar to symmetrical feathers in outgroup dinosaurs, indicating that selective regimes acted to modify primarily the leading-edge barb angles. These trends inform dynamics in feather shape evolution and challenge the notion that barb angle and barb angle ratios in extant birds directly inform the reconstruction of function in extinct stem taxa.

Frost growth behavior according to the cold surface inclination angle

Frosting experiments were performed to analyze the frost growth behavior according to the inclination angle of a cold surface. The thickness and density of frost on an inclined cold surface were analyzed with respect to a horizontal cold surface. The scattering of the frost particles and the initial shape of the frost crystals were observed. The frost thickness increased and the frost density decreased as the cold surface inclination angle increased, even with variable operating conditions (humidity and cold surface temperature). In the case of varying humidity, the initial frost crystals exhibited feather shapes under relatively high humidity conditions, and needle and pole shapes under relatively low humidity conditions. The decrease in frost density owing to frost particle scattering was significant when feather-shaped crystals were observed. As the cold surface temperature increased, the frost layer was strongly bound, and frost particle scattering occurred less frequently.

Gas entrainment behavior of aluminum alloy engine crankcases during the low-pressure-die-casting process

Gas pores on the top face of engine crankcases which are produced by Low Pressure Die Casting (LPDC) have been studied. Micrographic analysis has been conducted to investigate the evolution of such kind of casting defects. Results show that the surface of such casting defects have meandering shapes and random sizes. Microstructures of the cross section of the defects displayed folded feather shapes, which can be produced by the folded oxide film into the melt during the filling process. Oxide inclusions have been found below the filter at the ingate area. Thus, it is confirmed that the folded oxide films came from turbulence of the metal in the die cavity. Numerical simulation has been carried out to study the filling behavior of the crankcase. Results show that gating velocity suddenly increased when the liquid metal got into the waterfall structure and led to the turbulence. Moreover, the air entrained behavior is related with the gating velocity. With increasing gating velocity, turbulence happened when metal confluences, and became more intensely in the middle of the casting due to its waterfall structure. Finally, this kind of casting defect was confirmed as gas entrainment.

Diverse feather shape evolution enabled by coupling anisotropic signalling modules with self-organizing branching programme

Adaptation of feathered dinosaurs and Mesozoic birds to new ecological niches was potentiated by rapid diversification of feather vane shapes. The molecular mechanism driving this spectacular process remains unclear. Here, through morphology analysis, transcriptome profiling, functional perturbations and mathematical simulations, we find that mesenchyme-derived GDF10 and GREM1 are major controllers for the topologies of rachidial and barb generative zones (setting vane boundaries), respectively, by tuning the periodic-branching programme of epithelial progenitors. Their interactions with the anterior–posterior WNT gradient establish the bilateral-symmetric vane configuration. Additionally, combinatory effects of CYP26B1, CRABP1 and RALDH3 establish dynamic retinoic acid (RA) landscapes in feather mesenchyme, which modulate GREM1 expression and epithelial cell shapes. Incremental changes of RA gradient slopes establish a continuum of asymmetric flight feathers along the wing, while switch-like modulation of RA signalling confers distinct vane shapes between feather tracts. Therefore, the co-option of anisotropic signalling modules introduced new dimensions of feather shape diversification.

Theory of the development of curved barbs and their effects on feather morphology.

Feathers exhibit an extraordinary diversity of shapes, which are used by birds to accomplish a diverse set of functions. Pennaceous feathers have a double branched morphology that develops from a tube of epidermis, and variation in branch geometry determines feather shape. Feather development is both complex (i.e., a simple developmental modification can have multiple effects on mature feather shape), and redundant (i.e., different developmental modifications can create the same shape). Due to this, it is not readily apparent how different feather shapes develop. In many feathers, barbs are not straight, but instead curve in toward, or away, from the feather tip. Barb curvature can affect the shape of mature feathers but the development of curved barbs is unknown. Previous research has hypothesized that barb curvature could develop either during the helical growth of barb ridges in the tubular feather germ, or during barb angle expansion as the feather unfurls from the sheath. To better understand the development of curved barbs and their effects on mature feathers we present a theoretical model of curved barb development and test the model with empirical investigations of feathers. We find that curved barbs affect many aspects of feather morphology including vane width, barb length, and barb spacing. In real feathers, curved barbs can develop both during helical barb ridge growth and during barb angle expansion, with most of the observed curvature due to barb angle expansion. Our results demonstrate that barb angle expansion as a feather unfurls from the sheath is a complex and dynamic process that plays an important role in determining the shape and structure of mature feathers. Curved barbs create heterogeneity in barb geometry within the feather vane, which could have important implications for aerodynamic function and the development of within feather pigmentation patterns. J. Morphol. 277:995-1013, 2016. © 2016 Wiley Periodicals, Inc.

A New Surgical Model of Skeletal Muscle Injuries in Rats Reproduces Human Sports Lesions.

Skeletal muscle injuries are the most common sports-related injuries in sports medicine. In this work, we have generated a new surgically-induced skeletal muscle injury in rats, by using a biopsy needle, which could be easily reproduced and highly mimics skeletal muscle lesions detected in human athletes. By means of histology, immunofluorescence and MRI imaging, we corroborated that our model reproduced the necrosis, inflammation and regeneration processes observed in dystrophic mdx-mice, a model of spontaneous muscle injury, and realistically mimicked the muscle lesions observed in professional athletes. Surgically-injured rat skeletal muscles demonstrated the longitudinal process of muscle regeneration and fibrogenesis as stated by Myosin Heavy Chain developmental (MHCd) and collagen-I protein expression. MRI imaging analysis demonstrated that our muscle injury model reproduces the grade I-II type lesions detected in professional soccer players, including edema around the central tendon and the typically high signal feather shape along muscle fibers. A significant reduction of 30% in maximum tetanus force was also registered after 2 weeks of muscle injury. This new model represents an excellent approach to the study of the mechanisms of muscle injury and repair, and could open new avenues for developing innovative therapeutic approaches to skeletal muscle regeneration in sports medicine.

Tree Swallows' Feather-Lining Their Nest: An Anti-Parasitizing Strategy?

Abstract. I observed 12 nesting cycles of Tachycineta bicolor (Tree Swallow) with emphasis on the choice of nest materials used, timing of egg-laying, presence and behavior of conspecifics, and nesting success. All Tree Swallows built nests of dried grasses predominantly lined with large, plumed white feathers, but nest-lining behavior did not occur until after egg-laying began. When I experimentally removed feather-linings from one nest, the pair replaced them. In all nests, the birds tucked the feather quills under the eggs with the plumes arching over them. The Tree Swallows showed a strong preference both for shape of feathers and their color contrast from background. The Tree Swallows exhibited vigorous territorial behavior and nest-guarding from conspecifics before nest-building started, continued until early incubation, and then ceased when the young hatched. Birds other than the nest owners were frequent visitors in the nest area and they sometimes entered nests throughout the nesting cycle. Indir...

Behavioral changes and feathering score in heat stressed broiler chickens fed diets containing different levels of propolis

This experiment was conducted to evaluate the effects of dietary supplementation of green Brazilian propolis on behavioral patterns and feather condition of heat stressed broiler chickens. Five hundred and four (504) male Ross 708 broiler chicks at 15-day old were randomly allotted to six dietary treatments containing 0 (control), 100, 250, 500, 1000 and 3000mgkg−1 propolis, respectively. Each treatment consisted of four replicates of 21 birds each. Heat stress at 32°C was applied daily from 08:00 am to 17:00 pm from day 15–42. Twelve birds per treatment were randomly taken and marked with livestock color for behavioral observation. Treatment effects on behavioral patterns were recorded using direct observation instantaneous scan sampling technique. At the end of the experiment (42 days of age) the three birds used for behavioral observation were feather scored (from 1 to 5); while all birds (504) were individually scanned for primary feather abnormalities. The results indicated that the effects of using propolis as a feed additive for broilers reduced heat stress behavior, especially dietary treatment with 250 or 3000mgkg−1 propolis, by increasing bird walking activities and reducing panting behaviors (P<0.05, respectively). Moreover, 250mgkg−1 propolis (P<0.05) increased standing behavior also. Walking activities was also increased in the birds fed with 100mgkg−1 propolis (P<0.05). There were no significant (P>0.05) treatment effects on sitting, preening, feeding, drinking, wing elevations and feather pecking activities. Propolis at current doses did not significantly (P>0.05) improve feather scoring, but reduced (P=0.048) abnormal shape of primary feathers. The current results support that propolis treatment may be considered as a protective management practice in broiler chickens to alleviate the negative effects of heat stress, but further investigations may requested to determine the best type, dose, time and duration of its administration.

Preparation of Pd Nanoparticles with Tetrahedral, Spherical, Plate, and Feather Shapes by Capping with 1-Pentyl Isocyanide

In this study, we synthesized n-alkyl-isocyanide-protected palladium colloidal nanoparticles with different shapes. The 1-pentyl-isocyanide-protected Pd nanoparticles prepared by the reduction of the Pd complex with ethylene glycol had various geometric shapes. Transmission electron micrographs showed that tetrahedral particles were predominant, although some spherical, plate-, and feather-shaped particles were also observed. The enriched nanotetrahedra were isolated as a black powder by reprecipitation with methanol–chloroform and the particle size was controlled by the reaction conditions.