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

This work is licensed under a Creative Commons Attribution 4.0 International License.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. Pedal proportions and plumage support identification as an enantiornithine, but unlike previous discoveries the toes are stout with transversely elongated digital pads, and the outer toe appears strongly thickened relative to the inner two digits. The new specimen increases the known diversity and morphological disparity among the Enantiornithes, hinting at a wider range of habitats and behaviours. It also suggests that the Burmese amber avifauna was distinct from other Mesozoic assemblages, with amber entrapment including representatives from unusual small forms

An exquisitely preserved in-ovo 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 in-ovo 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. Comparison to other late-stage oviraptorid embryos suggests that prehatch oviraptorids developed avian-like postures late in incubation, which in modern birds are related to coordinated embryonic movements associated with tucking — a behavior controlled by the central nervous system, critical for hatching success. We propose that such pre-hatching behavior, previously considered unique to birds, may have originated among non-avian theropods, which can be further investigated with additional discoveries of embryo fossils

Subaqueous tracks of marine tetrapods – indications to trackmakers based on new surfaces from the Middle Triassic of Guizhou Province, China

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Mummified precocial bird wings in mid-Cretaceous Burmese amber

Our knowledge of Cretaceous plumage is limited by the fossil record itself: compression fossils surrounding skeletons lack the finest morphological details and seldom preserve visible traces of colour, while discoveries in amber have been disassociated from their source animals. Here we report the osteology, plumage and pterylosis of two exceptionally preserved theropod wings from Burmese amber, with vestiges of soft tissues. The extremely small size and osteological development of the wings, combined with their digit proportions, strongly suggests that the remains represent precocial hatchlings of enantiornithine birds. These specimens demonstrate that the plumage types associated with modern birds were present within single individuals of Enantiornithes by the Cenomanian (99 million years ago), providing insights into plumage arrangement and microstructure alongside immature skeletal remains. This finding brings new detail to our understanding of infrequently preserved juveniles, including the first concrete examples of follicles, feather tracts and apteria in Cretaceous avialans

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)]. The new fossil preserves large compound eyes, delicate mouthparts, and even gills. This modern-looking crab is nested within crown Eubrachyura, or “higher” true crabs, which includes the majority of brachyuran species living today. The fossil appears to have been trapped in a brackish or freshwater setting near a coastal to fluvio-estuarine environment, bridging the gap between the predicted molecular divergence of nonmarine crabs (~130 Ma) and their younger fossil record (latest Cretaceous and Paleogene, ~75 to 50 Ma) while providing a reliable calibration point for molecular divergence time estimates for higher crown eubrachyurans

Folate monoglutamate in cereal grains: Evaluation of extraction techniques and determination by LC-MS/MS

Folates are essential micronutrients for human health. To determine the total folate content, the extraction and quantification of seven monoglutamate folate derivatives in cereals (maize, rice, and wheat) were optimised and validated in this study. Di-enzyme treatment with α-amylase and rat conjugase was proved ideal for folate extraction from the cereal grains. The quantification method by liquid chromatography-tandem mass spectrometry was validated based on its matrix effect, linearity, sensitivity, recovery, inter-day and intra-day precision. The limits of detection and quantification of folate derivatives ranged from 0.03–0.88 and 0.1–1.0 μg/100 g among the three cereal samples. The absolute recoveries of most folate derivatives were 72–96 % for these cereal samples, with the exception of dihydrofolate, tetrahydrofolate, and folic acid (44–65 %). The inter-day and intra-day precisions were < 12 % for the three cereals. Analysis of folate content and composition in several cereal grains showed that the total folate levels were approximately 26−37 μg/100 g, with 5-methyl-tetrahydrofolate and 5-methyl-tetrahydrofolate as the dominant. MeFox, an oxidation product of 5-methyltetrahydrofolate, was detected at concentrations 20–39-fold higher than those of total folates in rice and wheat grains. This validated method is an efficient approach for folate determination in cereal crops

Sistem Pengendali Kecepatan Motor Dc Pada Lift Barang Menggunakan Kontroler Pid Berbasis Atmega 2560

Lift barang adalah angkutan transportasi vertikal digunakan untuk memindahkan barang. Lift ini sangat khusus fungsinya untuk barang saja, lift ini hampir sama dengan lift penumpang namun ada sedikit perbedaan dalam sistem keamanannya. Lift barang yang sekarang memang sudah otomatis tetapi hanya pada gedung bertingkat tinggi. Untuk minimarket atau home industry yang memiliki struktur bangunan 2 lantai, banyak dijumpai masih menggunakan pengkatrolan secara manual oleh tenaga manusia untuk memindahkan barang. Hal ini cukup tidak efisien. Pada penelitian ini telah dirancang sistem pengaturan kecepatan motor DC pada lift barang menggunakan kontoler PID dengan kontruksi sistem yang sederhana. Digunakan Kontroler PID untuk mengurangi kesalahan, sehingga putaran motor dapat sesuai dengan kecepatan yang diinginkan. Dengan bantuan kontroler PID maka lift barang mampu bergerak dengan aman dan halus. Pada skripsi ini digunakan metode Ziegler-Nichols tunning 2. Dalam pembuatannya digunakan Arduino Mega 2560, rotary encoder Autonic E40H8 500-6-L-5, limit switch, dan motor DC. Berdasarkan data respons sistem yang diperoleh dari pengujian dengan menggunakan metode kedua Ziegler-Nichols, maka parameter kontroler PID dapat ditentukan dengan gain Kp = 7.71, Ki = 7.035 dan Kd = 2.113.Kata Kunci— Lift barang, Pengendalian Kecepatan, PID, Arduino Mega 2560

Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs

Relationships between non-avian theropod dinosaurs and extant and fossil birds are a major focus of current paleobiological research. Despite extensive phylogenetic and morphological support, behavioural evidence is mostly ambiguous and does not usually fossilize. Thus, inferences that dinosaurs, especially theropods displayed behaviour analogous to modern birds are intriguing but speculative. Here we present extensive and geographically widespread physical evidence of substrate scraping behavior by large theropods considered as compelling evidence of "display arenas" or leks, and consistent with "nest scrape display" behaviour among many extant ground-nesting birds. Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred