The semimembranosus muscle (SM) is a key component of the posterior thigh and an integral part of the hamstring group. It plays a crucial role in lower limb movement, particularly in knee flexion, hip extension, and medial rotation of the tibia (with the knee flexed), in cooperation with other muscles of the hamstring complex. The aim of this study was to assess the anatomy and morphometry of the SM proximal tendon. The proximal tendon of the semimembranosus muscle was carefully dissected and examined in 60 cadaveric specimens (32 left and 28 right) obtained from 60 cadavers (27 females and 33 males). During dissection, one tendon variant was identified on the medial side, whereas two tendon variants (Type I and Type II) were distinguished on the lateral side. Type I was observed in 42 specimens, while Type II was identified in 18 specimens. Morphometric parameters, including the lateral and medial lengths of the superficial part of the SM tendon, the lateral and medial lengths of the deep part of the tendon, as well as tendon thickness and width, were measured in detail. This study demonstrates that the proximal tendon of the semimembranosus muscle exhibits distinct anatomical variability. These findings may provide valuable reference data for clinicians, particularly orthopedic surgeons and radiologists, in the diagnosis and treatment of hamstring injuries.

Background and Clinical Significance: Primary Cutaneous Cribriform Apocrine Carcinoma (PCCAC) is a rare, inert low-grade cutaneous malignancy that is diagnosed on histopathologic assessment. PCCAC usually presents in middle-aged adults as a solitary, subcutaneous nodule on the extremities. Characterized by anastomosing tubules and solid/cribriform nests of atypical epithelial cells generating a sieve-like display, the tumor is a histopathological variant of apocrine metaplasia of the skin. PCCAC also follows characteristic staining patterns. It is important to distinguish PCCAC from other similar histological variants, which may hold more grievous indications. Case Presentation: A 47-year-old female presented with an enlarging, itchy growth of several months on her back. On physical exam, an indurated pink, nontender papule of 8 mm on the left lateral side wall was noted. Histopathology demonstrated a well-circumscribed, pandermal tumor composed of anastomosing solid and cribriform nests, tubules, and cords of mildly atypical, eosinophilic epithelial cells forming a glandular lumina. An immunohistochemical study revealed the tumoral epithelium to express CK7, CK5/6, BER-EP4, CD117 (C-kit), and S100. Positive EMA and CEA staining highlighted intratumoral glandular ductal differentiation and apocrine secretion. Immunohistochemical stains for CK20, GATA-3, and p63 were negative. Conclusions: We present this case to distinguish the histological attributes of PCCAC and help differentiate it from more concerning visceral metastatic malignancies. We follow with a narrative review of the histopathologic differential for PCCAC and feature reconciliation of corresponding staining patterns reported in the literature.

We have reconsidered the formation and stability of a vortex street, induced in a rectangular container by a tape moving at high speed on its free surface. In a certain range of tape velocity and of geometrical aspect ratios, the liquid recirculates along the lateral sides of the pool, which induces two shear flows between the tape and these lateral sides, that undergo two coupled Kelvin-Helmholtz instabilities, giving rise to the vortex street. Contrary to the classical situation of a wake behind an obstacle, the double row remains static which allows one to study its absolute stability in a stationary framework. In the present paper we present a stability analysis around the mean flow that clarifies the wavelength selection problem, inside the stability tongue predicted long ago by Rosenhead, and reduced by steric arguments that we found in a previous paper. In summary the mean wavelength favored by shear flow instabilities is given by , where c is half the channel width, while the maximal wavelength predicted by marginal stability is equal to . Our available experimental data are in very good agreement with these results and with the resulting phase diagram.

Egg glue secretion and chorion morphology of the Southern Green Stinkbug Nezara viridula L. (Hemiptera: Pentatomidae).

Jaw movement trajectories on the horizontal plane in sleep bruxism.

Variable bladder filling during radiotherapy for carcinoma cervix significantly affects the position of target volumes to be treated. This directly impacts the precision with which advanced radiotherapy plans are delivered using specific margins to target volumes. The aim is to study mean bladder volumes and mean range of bladder motion in all three dimensions in patients of carcinoma cervix treated with Image guided radiation therapy (IGRT), and compare them to the baseline planning Computed tomography (CT) scans. For this, a total number of 25 patients/ 150 CT scans, i.e. 25 planning scan and 125 CBCT (cone-beam CT) were analyzed. The bladder volumes and bladder wall dimension were analyzed using offline views of CBCT imaging, conducted weekly for cervix cancer patients, thus adding considerable understanding to the bladder wall motions. The mean bladder volume for all 25 patients was 263.41 cc with standard deviation of 110.174 cc. When mean CBCT bladder volumes of each patient were compared to their respective planning CT bladder volumes, P was found to be insignificant (p=0.25), showing consistent bladder filling or reproducibility during treatment. The mean ± standard deviation of bladder’s transverse, anteroposterior and supero-inferior dimension was 9.55 ± 0.923 cm; 6.92 ± 2.387 cm and 7.22 ± 0.967 cm. The mean supero-inferior bladder diameter had significant variation from that of the planning CT (7.84 ± 2.749 cm vs 6.92 ± 2.387) with p = 0.018. This study shows that more liberal margins should be considered in supero-inferior dimensions and considerable lesser margins could be given on the lateral sides, as there is less displacement in transverse diameter.

Purpose: This study aimed to examine how age, sex, and race affect maxillary sinus pneumatization. Additionally, it aimed to determine which tooth on each side caused greater sinus pneumatization following extraction among Spanish and Egyptian patients. Materials and Methods: Two protocols were used to assess maxillary sinus pneumatization digitally in 440 panoramic X-rays. The sample included 220 Spanish and 220 Egyptian patients, both male and female, aged 20 years or older. All patients had one or more maxillary posterior teeth extracted (from the first premolar to the third molar) on one side, with the contra lateral side fully dentate . Results: Younger patients have a higher likelihood of sinus penetration with roots. The distance between the maxillary sinus and teeth is smaller in men than in women. No significant differences were observed between the right and left sides. In Spanish patients, the greatest pneumatization occurs after the second molar extraction, followed by the first molar. In Egyptian patients, the highest pneumatization is associated with extracting the second premolar, followed by the first molar. The distance to the maxillary sinus was significant in both populations. Univariate analyses showed non-significant extraction effects with varying effect sizes. The highest adjusted R² values were observed at the first molar in Egyptian and the second molar in Spanish patients. Conclusion: Maxillary sinus volume changes with age; as age increases, the volume decreases. There is no significant difference in gender regarding the tooth-sinus-floor distance, but males show larger sinuses. No significant difference is seen between the right and left sides.

Objective: Lymphatic scintigraphy using radioisotope agents is a good method for evaluating the lymph flow status of patients with lower-limb lymphedema. To depict wide regions of lower-limb lymphatic vessels, at our institution, we administer radioisotopes at four locations in each limb when lymphatic scintigraphy images are to be obtained. Herein, we evaluated the correlation of lymphatic scintigraphy with lymphedema staging and investigated the usefulness of this four-point dermal-injection lymphatic scintigraphy (LyS4).Materials and methods: The 52 lower limbs of 26 patients (23 females, three males, aged 20-85 years, median 65 years) underwent a LyS4 examination of their lower limbs. The stage of lower-limb lymphedema was diagnosed by plastic surgeons at our institution using the International Society of Lymphology (ISL) staging system. The patients' ISL stages were stage 0 (n=20), stage 1 (n=7), and stage 2 (n=25). No patient was stage 3. For each LyS4 examination, technetium-99m human serum albumin diethylenetriamine pentaacetic acid (99mTc-HSA) was injected. The four injection points were the first interdigital web, slightly below the area of the lateral malleolus, slightly below the area of the medial malleolus, and the lateral side of the feet near the fifth digit of both feet. Using the planar LyS4 images, we investigated the positive/negative appearance of the four lymphatic vessel regions, i.e., anteromedial (AM), anterolateral (AL), posteromedial (PM), and posterolateral (PL) and the dermal backflow (DB). We then examined the correlations of these parameters with the ISL stage.Results: The absence of AM, the absence of PM, the appearance of DB, and the number of lymphatic vessels depicted were each significant factors for distinguishing lymphedema. The appearance of DB and the number of lymphatic vessels depicted can distinguish moderate lymphedema (ISL stage 0 or 1) from severe lymphedema (ISL stage 2e or 2d). Regarding the diagnostic performance of the LyS4 parameters, high accuracy was observed for the appearance of PM (0.71), that of DB (0.79), and the number of depicted lymphatic vessels (0.77).Conclusion: LyS4 is a useful method with good correlation with the ISL stage in patients with lower-limb lymphedema.

Horizontal curves on downgrades, commonly found in mountainous terrain, have higher crash rates and severity than tangents or pure curves. The lateral stability of tractor-semitrailers on such curves is a significant concern due to their heavy load, high center of gravity, and long-distance use. The combined impact of highway alignments and truck configurations has not been comprehensively studied due to data limitations. To address the high cost of experimental tests, a high-fidelity vehicle dynamics simulation model is used to investigate the rollover and sideslip propensity of tractor-semitrailers navigating curves on downgrades with varying geometric designs and truck characteristics. Lateral Transfer Ratio and side friction demand are used as criteria for rollover and sideslip stability, respectively. The multi-step Taguchi method is applied to identify the most influential factors on lateral stability. Results show that the tractor static toe angles (axle 1) have the most significant impact on sideslip stability, followed by tractor static toe angles (axle 2 & 3) and tractor yaw stiffness. The trailer height of load significantly affects rollover stability, followed by tractor axle 2 longitudinal distance and trailer static toe angle. Longitudinal slope has the greatest impact on rollover and sideslip stability, while the radius of the horizontal curve has the least effect. Focusing on these influential factors, rather than numerous tractor-semitrailer parameters, could aid in optimizing vehicle and highway design, as well as traffic control and management.

Previous studies suggest that the retinaculum on the lateral side of the triceps brachii muscle, often referred to as the lateral cubital retinaculum (LCR), contributes to elbow extension. The LCR provides continuity of the extensor mechanism with the ulna and contributes to the stable transmission of elbow extension force. However, its precise anatomical definition and biomechanical roles remain unclear. In addition, surgical approaches such as the triceps fascial tongue technique, which is commonly used by elbow surgeons to provide wide posterior access, risks the detachment of the LCR insertion area. We sought to investigate the anatomical features of the retinaculum and assess its biomechanical role during the triceps tongue approach by answering the following questions in a cadaver study: (1) What kind of anatomical characteristics (the length and width of the LCR and the olecranon width) are present at the ulnar insertion of the LCR? (2) Does isolation of the LCR affect extensor lag of the elbow in the triceps fascial tongue approach? (3) Can surgical repair of the LCR restore extensor lag of the elbow? We defined "extensor lag" as changes in elbow angle due to the dissection or repair of the LCR or the triceps tendon compared with the intact condition when a constant tension was applied to the triceps tendon. In total, 24 fresh-frozen upper extremities from 3 female and 15 male cadavers (mean ± SD age 84 ± 7 years) were included. Fourteen specimens from 8 cadavers were used in the anatomical study of the LCR. After exposing the triceps brachii and antebrachial muscles, the triceps tendon and lateral spreading fibers of the LCR were identified. The width and length of the lateral insertion of the LCR to the ulna were measured. Biomechanical studies were performed using the remaining 10 elbows to investigate the role of the LCR in elbow extension while elevating the triceps fascial tongue with a posterior surgical approach to the elbow. To determine whether isolation and repair of the LCR affects extensor lag, we measured elbow angle changes under 2 kg and 4 kg of traction, which is 10% to 20% of maximal muscle strength. The elbow was fixed in a custom jig, and a three-dimensional (3D) motion-tracking tool was used for spatial analysis. Elbow flexion angles under 2 kg and 4 kg of triceps traction were measured using the 3D motion tracking system. The measurements were performed under the following conditions: (1) intact LCR and triceps tendon, (2) elevation of a triceps fascial tongue flap with intact LCR in a surgical posterior approach, (3) additional LCR isolation from the ulna (1 to 5 cm), and (4) LCR repair. Repeated-measures ANOVA was used to evaluate interactions between traction force and elbow angle, with post hoc Holm tests. A p value < 0.05 was considered significant. At the tip of the olecranon, the width of the LCR was 18 ± 3 mm and the length of the ulnar insertion area was 43 ± 5 mm. Isolation of the LCR using a triceps tongue approach resulted in a larger elbow flexion angle under 2 kg or 4 kg of load than was observed when an approach that involved elevating the triceps only was used (2 kg: 83° ± 4° versus 79° ± 5°, mean difference 4° [95% confidence interval (CI) 1° to 7°]; p = 0.049; 4 kg: 80° ± 7° versus 73° ± 8°, mean difference 7° [95% CI 3° to 11°]; p = 0.008). Repair of the LCR resulted in a smaller flexion angle under 2 kg or 4 kg of load than was observed when isolating the LCR using a triceps tongue approach (2 kg: 80° ± 5° versus 83° ± 4°, mean difference 3° [95% CI 1° to 7°]; p = 0.049; 4 kg: 75° ± 7° versus 80° ± 7°, mean difference 5° [95% CI 3° to 9°]; p = 0.008). Quantitative anatomical and biomechanical studies have shown that isolation and repair of the LCR during the triceps tongue approach affects the angle of the elbow. Based on these results, we concluded that isolation of the ulnar insertion of the LCR may cause elbow extension impairment and that repair may improve this condition. Preservation or repair of the LCR may help prevent postoperative extension force transmission disorders in elbow arthroplasty and trauma surgery using the triceps fascial tongue approach. Future research should focus on evaluating the effects of LCR isolation and repair through clinical studies.

BackgroundAcrel’s “pseudo-ganglion” is a ganglioform structure found on the floor of the fourth dorsal extensor compartment. The function of Acrel’s “pseudo-ganglion” is undetermined within published literature; however, recent histological studies suggest it to be devoid of nerve cell bodies and is, therefore, a “pseudo-ganglion." Advances in ultrasound technology have made it possible to better visualize nerves in vivo. This study aims to investigate any ganglioform structure at the termination of the posterior interosseous nerve, using ultrasound, cadaveric dissection, and histological studies. Materials and methodsTwenty wrists from 10 formalin-fixed cadavers were dissected and examined. Standard haematoxylin and eosin staining of cadaveric samples was performed to check for the presence of any ganglionic cells and other cellular organizations. Ultrasound examination of the wrists of 10 live humans, using a GE LOGIQ e ultrasound system manufactured by GE Healthcare at Chicago, USA, with a 12L-RS transducer, was performed, looking for a non-compressible hypoechoic ovoid structure on the lateral side of the fourth extensor compartment, medial to Lister’s tubercle in accordance with the described location of Acrel’s “pseudo-ganglion." ResultsA ganglioform swelling was found in all cadavers, which corresponded to a non-compressible hypoechoic ovoid structure under ultrasonography, on the radial/lateral side of the fourth extensor compartment, and ulnar/medial to the dorsal/Lister’s tubercle. Standard haematoxylin and eosin staining from cadaveric samples showed the absence of any neuronal cells and inflammatory cells. ConclusionUnderstanding the termination of the posterior interosseous nerve under different modalities enabled us to gain knowledge about Acrel’s “pseudo-ganglion,” and this can aid in the assessment of various wrist pathologies linked to tendons around the wrist and their relation to this ganglioform swelling, named Acrel anglion. It may also help in refining clinical applications, being minimally invasive through the use of ultrasound and targeting that precise location.

Anterior Cruciate Ligament (ACL) injury is common in sports that require quick changes of direction, jumps, and impacts, being more prevalent in male athletes. The ACL is responsible for approximately 85% of the restraint of anterior tibial translation relative to the femur, as well as stabilizing knee rotation. Its rupture generally occurs due to excessive valgus mechanisms, knee rotation with the foot fixed, or direct trauma to the lateral side of the knee. Treatment can be surgical, using grafts from the patellar tendon or hamstrings, or conservative, indicated in partial injuries. Post-surgical rehabilitation aims to reduce inflammation, preserve range of motion (ROM), maintain balance, proprioception, and prevent muscle hypotrophy. This study, a bibliographic review based on the PICO method, aims to compare the effects of open kinetic chain (OKC) and closed kinetic chain (CKC) exercises in the rehabilitation of athletes with ACL injuries. Preliminary results indicate that CKC exercises provide less joint stress and greater muscle activation, promoting proprioception, balance, and a safer return to activities. OKC exercises, although posing a risk of overload if used too early, are effective in the intermediate and final phases for specific strengthening, ROM gains, and motor control. The study advocates the progressive integration of both approaches, respecting tissue healing phases and sports demands, providing efficient, functional, and safe rehabilitation. It also emphasizes the importance of individualizing protocols according to the athlete’s profile.

Objective: A C57/BL6 mouse model of traumatic temporomandibular joint ankylosis (TTMJA) was established through composite trauma to lay the foundation for studying the pathophysiology of TTMJA. Methods: This study was conducted from January 2024 to February 2025. Forty-two 4-weeks old C57/BL6 mice, numbered 1 to 42, are randomly assigned to a control group (n=21) and an experimental group (n=21) using a computer-generated random number sequence. The experimental group undergoes modeling surgery on the left temporomandibular joint (TMJ), while the control group is routinely raised without special treatment. At 12 weeks post-surgery, the TMJ complex of both groups is assessed via body weight and mouth opening measurements, gross observation, micro-CT, and histological staining to evaluate model establishment. Results: At 12 weeks post-operation, in the experimental group, the body weight of mice [(27.75±1.08) g] did not show a significant difference compared with that of the control group [(30.80±0.29) g](t=0.54,P=0.610). The maximum vertical passive mouth opening [(1.70±0.26) mm] in the experimental group was significantly lower than that in the control group [(3.43±0.21) mm](t=8.92,P<0.001). Gross observation indicated that the right TMJ structure of the experimental-group mice was normal, while irregular hyperplasia occurred in the left TMJ complex. Micro-CT revealed that at 12 weeks post-operation, the right joint structure of the experimental-group mice was normal, with regular condyles and glenoid fossae. On the left side, a large amount of bone hyperplasia occurred on the lateral side of the joint in the condyles and glenoid fossae, forming two irregular bone masses, and there was an uncalcified radiolucent zone between the bone masses. In histological staining, no new cartilage or bone tissue was observed in the left joint space of the control-group mice, and the articular disc structure was normal. In the experimental-group mice, obvious new cartilage and calcified bone tissue were visible on the lateral side of the left joint space. A bone bridge was formed between the condyles and glenoid fossae, the articular disc structure disappeared, and bony ankylosis occurred. Conclusions: In this experiment, a TTMJA model of C57/BL6 mice was initially established by removing the articular disc and damaging part of the fibrous cartilage of the glenoid fossae and condyles, providing an experimental platform for further research on the pathogenesis of TTMJA.

Increased force and contact area in the lateral compartment may predispose to arthritis progression after balanced unicompartmental knee arthroplasty: A cadaveric comparison.

Background:Diabetic forefoot ulcers often result from increased pressure on bony prominences, neuropathy, and poor limb perfusion. The management of these ulcers, particularly when infected, is challenging and can often lead to minor or even major amputation. This study aims to evaluate the efficacy and safety of minimally invasive surgical offloading of recurrent diabetic ulcers of the fifth metatarsal by minimally invasive fifth metatarsal osteotomy and bunionette removal.Methods:A retrospective case series study was conducted of patients who underwent surgical treatment for diabetic foot ulcers on the lateral or plantar side of the fifth metatarsal head between January 2020 and May 2025. Outcomes included time to healing of the primary ulcer and surgical wound, ulcer recurrence, postoperative complications, and reoperation rates. Clinical and radiologic parameters of the feet were assessed, and patient satisfaction Coughlin scores were collected.Results:Ten feet from 9 patients who did not respond successfully to conservative offloading were included. The mean age of the patients was 69.5 years. Five feet were classified as Wagner grade 3 wounds, and 4 as Wagner grade 2 wounds. The ulcers healed completely in a mean time of 9.8 weeks postoperatively. Two patients required 6 weeks of antibiotic treatment because of preexisting osteomyelitis. One postoperative infection occurred. There were no corrective failures, and all patients returned to wearing orthopaedic shoes postoperatively. The overall patient satisfaction using the Coughlin satisfaction score was “good” to “excellent.”Conclusion:Minimally invasive fifth metatarsal osteotomy with bunionette removal appears safe and effective for treating refractory diabetic ulcers of the fifth metatarsal head, including cases with active infection. However, larger studies with functional outcomes are needed to establish definitive treatment guidelines.Level of Evidence:Level IV, case series.

The sense of touch (mechanoreception) in snakes is not widely appreciated despite emerging evidence of tactile specialisation among sea snakes. This is partly due to the challenges in quantifying small (< 1 mm) and numerous scale mechanoreceptors concentrated on the head. By using a novel application of gel-based 3D profilometry (GelSight scanner) in combination with histology and scanning electron microscopy, we comprehensively quantified the morphology and distribution of scale mechanoreceptors in the olive-headed sea snake, Hydrophis major (Hydrophiinae), for the first time. H. major is one of the few predators to eat eel-tailed catfishes (Plotosidae), which have venomous spines that they lock into erect positions during defence. We discovered that in addition to the radially symmetrical smooth, dome-shaped mechanoreceptors typically found in sea snakes, H. major has asymmetrical, peak-shaped mechanoreceptors that are significantly larger but rarer. Smooth domes are distributed in decreasing density antero-posteriorly on the head with the highest densities on the snout and labial scales. Asymmetrical peaks are rarer; they are detected only on the dorsal and lateral sides of the head, are most dense behind the eye, and their associated dermal papilla (that contains mechanosensitive cells) is spatially offset from the stiff peak. Based on their morphology and distribution, we suggest functional differences in mechanosensory modalities: (1) smooth domes for direct touch used in prey handling to avoid dangerous spines of catfish prey, and (2) asymmetrical peaks that create a lever system capable of amplifying directional water flow. The latter might allow H. major to detect the C-start escape response of free-swimming catfish and/or enhance kinaesthesia for the snake's perception of self-motion during foraging and predatory strikes, but physiological studies are needed to investigate these functional hypotheses further.

Axonal sprouting from adjacent dorsal root ganglia following cervical dorsal root avulsion in mice.

Sanitary napkins are essential during menstruation, but they can sometimes cause skin irritation due to friction. In this study, we propose a novel design: introducing a low-friction layer within the bulk of a sanitary napkin. Friction tests were conducted between an artificial skin block and sanitary napkin specimens with and without a low-friction layer. The strain distribution on the lateral side of the artificial skin block was experimentally measured. The friction coefficient and strain decreased when the low-friction layer was applied under loads greater than 1.96 N. The strain increased with normal load. Because lower strain on the skin correlates with reduced skin irritation, the use of a low-friction layer in sanitary napkins is expected to reduce skin irritation, particularly under high contact pressure.

The osteoarticular involvement of Brucella infection may present as arthritis, bursitis, tenosynovitis, or spondylitis. Isolated presentation of Brucella infection as bursitis is a rare occurrence. The objective of this report was to present two cases of Brucella infection presenting with isolated prepatellar bursitis as osteoarticular involvement. The initial case report concerns a 56-year-old female patient who presented with a complaint of swelling in the left knee, accompanied by minimal pain, which had been present for the previous year. The second patient was a 53-year-old male patient who presented with a complaint of painless swelling in the knee, which had first appeared two years prior and had progressively worsened. Physical examination observed swelling extending from the anterior to the lateral side of the left knee, with no erythema, warmth, or tenderness observed in both patients. Laboratory examinations revealed normal biochemical parameters, complete blood count, and erythrocyte sedimentation rate (ESR), but C-reactive protein (CRP) levels were three times higher than the cut-off value. Serological tests revealed Brucella IgG positivity. Following the investigations, surgery was planned, and through a longitudinal incision, the masses were reached and completely excised. The resected tissue’s pathological examinations revealed chronic granulomatous inflammation. In endemic regions such as the one under consideration here, Brucella bursitis should be considered in the context of isolated and suspected osteoarticular involvement, regardless of the presence of any features in the patient’s history. Clinical suspicion plays a pivotal role in the preliminary diagnosis of Brucella bursitis, guiding clinicians in the early diagnosis and effective treatment of the disease.

Seven new extinct species belonging to two subgenera (Amelyris Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, subgen. nov. and Asymelyris Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, subgen. nov.) within extinct genus Amelyris Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, gen. nov. are described and illustrated from inclusions in late Eocene European ambers (Baltic, Rovno, and Danish) as the first reliable fossils of the family Melyridae. The newly described taxa are included in the new tribe Amelyrini Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, trib. nov., which can be distinguished from the extant tribes of the subfamily by the following characters: (1) penultimate antennomeres oval-triangular with rounded edges, (2) elytral punctation between longitudinal carinae regular, arranged in three rows, (3) pronotum with strongly carinate lateral sides, (4) pronotal surface with pronounced foveolate punctation, (5) tarsomeres with strong semi-erect dark setae ventrally, and (6) body size comparatively small (2.53.8 mm). The keys to subfamilies and tribes of Melyridae, as well as to all species of the newly described genus, namely Amelyris (Amelyris) sveneldi Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, sp. nov., A. (Amelyris) elongatus Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, sp. nov., A. (Amelyris) tricarinatus Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, sp. nov., A. (Asymelyris) paucidentatus Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, sp. nov., A. (Asymelyris) lupatus Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, sp. nov., A. (Asymelyris) groehni Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, sp. nov., and A. (Asymelyris) jutlandicus Tshernyshev, Alekseev, Bukejs, Vasilenko, Legalov & Perkovsky, sp. nov., are provided.