Surface Anatomy Research Articles

Automatic Image Registration Provides Superior Accuracy Compared with Surface Matching in Cranial Navigation.

The precision of neuronavigation systems relies on the correct registration of the patient's position in space and aligning it with radiological 3D imaging data. Registration is usually performed by the acquisition of anatomical landmarks or surface matching based on facial features. Another possibility is automatic image registration using intraoperative imaging. This could provide better accuracy, especially in rotated or prone positions where the other methods may be difficult to perform. The aim of this study was to validate automatic image registration (AIR) using intraoperative cone-beam computed tomography (CBCT) for cranial neurosurgical procedures and compare the registration accuracy to the traditional surface matching (SM) registration method based on preoperative MRI. The preservation of navigation accuracy throughout the surgery was also investigated. Adult patients undergoing intracranial tumor surgery were enrolled after consent. A standard SM registration was performed, and reference points were acquired. An AIR was then performed, and the same reference points were acquired again. Accuracy was calculated based on the referenced and acquired coordinates of the points for each registration method. The reference points were acquired before and after draping and at the end of the procedure to assess the persistency of accuracy. In total, 22 patients were included. The mean accuracy was 6.6 ± 3.1 mm for SM registration and 1.0 ± 0.3 mm for AIR. The AIR was superior to the SM registration (p < 0.0001), with a mean improvement in accuracy of 5.58 mm (3.71-7.44 mm 99% CI). The mean accuracy for the AIR registration pre-drape was 1.0 ± 0.3 mm. The corresponding accuracies post-drape and post-resection were 2.9 ± 4.6 mm and 4.1 ± 4.9 mm, respectively. Although a loss of accuracy was identified between the preoperative and end-of-procedure measurements, there was no statistically significant decline during surgery. AIR for cranial neuronavigation consistently delivered greater accuracy than SM and should be considered the new gold standard for patient registration in cranial neuronavigation. If intraoperative imaging is a limited resource, AIR should be prioritized in rotated or prone position procedures, where the benefits are the greatest.

Enhanced Prenatal and Postnatal Development Study in Marmoset Monkeys Following Administration of Felzartamab.

Felzartamab is a recombinant fully human immunoglobulin G1 anti-CD38 monoclonal antibody under clinical investigation for immune-mediated diseases. In support of felzartamab clinical development, toxicology studies were conducted in marmoset monkeys, which was the most relevant species based on CD38 binding affinity, pharmacologic activity, and target expression. The felzartamab toxicology program included an enhanced prenatal and postnatal development (ePPND) study to identify potential reproductive and postnatal development risks. In this ePPND study, pregnant marmoset monkeys were randomized to receive vehicle (0mg/kg) or felzartamab at two dose levels (15mg/kg and 75mg/kg) twice per week until parturition, and maternal animals and infants were evaluated for 6 months thereafter. Felzartamab exposure was confirmed in maternal animals and infants in both dosing groups. Overall, felzartamab was well tolerated by pregnant animals at the evaluated doses, with no effect on body weight or body weight gain during pregnancy. No felzartamab-related effects on pregnancy loss or stillbirth rate were observed, and litter counts and numbers of liveborn infants were similar between the vehicle and felzartamab groups. Among infants, there were no felzartamab-related malformations or variations in external anatomy or skeletal morphology and no felzartamab-related observations in histopathology, hematologic and immune cell development, or humoral immune response to vaccination. In conclusion, among pregnant marmoset monkeys dosed with felzartamab, the lack of reproductive toxicity and felzartamab-related effects on offspring supports the clinical evaluation of felzartamab in women of childbearing potential and further demonstrates the suitability of the marmoset monkey for ePPND studies.

Clinical Performance of 3D Printed Resin Composite Posterior Fixed Dental Prosthesis: A Permanent Solution?

This clinical trial aimed to evaluate the clinical outcomes of 3D-printed resin composite posterior fixed dental prosthesis (FDP) restorations. Between October 2020 and August 2022, 49 patients (33 females, 16 males, aged 19-60) received 68 3-unit 3D-printed resin composite posterior FDPs (ELS Even Stronger, Saremco, Switzerland). Follow-ups were conducted at baseline (2 weeks) by independent observers using modified FDI criteria, assessing anatomical form, marginal adaptation, surface roughness, color match, fracture, retention, and patient feedback. Fifty FDPs completed a 1-year follow-up, and 18 reached 2 years. The mean observation period was 14.15 months. Failures were categorized as mechanical or biological, with 19 FDPs failing: 14 mechanical (12 cohesive fractures) and 5 biological (3 needing endodontic treatment, 2 periodontal issues). Two FDPs were recemented. Three FDPs showed surface luster loss, color mismatches, and staining. The survival rate based on mechanical failures was 69.5%, dropping to 61.0% when including biological complications. After 2 years, 3D-printed resin composite FDPs demonstrated acceptable performance, with most failures due to fractures in the connector region, suggesting the need for design revisions.

Medical Alert Cards for patients with an anorectal malformation: a useful tool to increase awareness.

Anorectal malformations (ARMs) are rare congenital anomalies causing altered anatomy and frequent hospitalizations. Parental awareness and clear communication are crucial in family-centered care. This study assesses the impact of patient-held ARM Medical Alert Cards on healthcare providers and caregivers. Caregivers of children with ARMs, including cloacal anomalies, received Medical Alert Cards with (1) contact details; (2) disease-related information; and (3) patient-specific data. A survey evaluated these cards' effectiveness in enhancing ARM awareness among healthcare professionals and caregivers. Among 33 respondents, 29 (88%) found the cards helpful in increasing ARM awareness. Both caregivers and providers found the content coherent, with a median readability score of 9 (IQR 8-10). The card layout was well-received by 30 out of 32 respondents (94%), and all noted the clarity of the contact details, facilitating patient referrals to specialized care. Most caregivers (13 out of 14, 93%) expressed willingness to use these cards in medical settings. Suggestions for improvement included adding more patient-specific information, enhancing readability, and providing visual anatomy diagram. Medical Alert Cards for patients with ARMs can enhance understanding of ARMs among caregivers and healthcare providers, serving as a vital tool in patient-centered management strategies tailored to individual needs.

The Champati Slide

Here, we report some novel findings of chute experiments with native Nepalese granular seeds, called Champatis, and when mixed with other food grain of a fundamentally different physical properties, Silam. The epitomic supergrain Champati exhibits complex frictional, spin, and rolling motion. We hypothesize that the Champati slide results in an essentially unique dynamical spreading, separation from other grains, mobility, run-out, and deposition morphology. Particularly, the surface anatomy of Champati acted vitally in characterizing these aspects. We reveal spectacular dynamical flow–obstacle interaction and depositional behavior of Champati and the mixture slide. Champati slide manifests hyper-spreading in the run-out. Soon after the mass hits the ground, the behavior is unprecedented and appears to be hardly predictable, mainly around the frontal periphery. The very special properties of Champatis control the frontal spreading, rapid grain marching, and their zig-zag sporadic motion. Particle rolling, spinning, exceptionally lower frictional energy dissipation, and grain collision played the major role resulting in an unexpectedly longer travel time and distance, explaining the astonishing hypermobility of Champati grains. The obstacle substantially changes the flow dynamics as the Champati exhibits high object mobilization capacity. Due to the unique property of the Champati, the eye-catching, amazingly strong separation of Champati from Silam evolves swiftly right after the flow inception, and the process intensifies quickly. The separation length characterizes the complex interfacial momentum exchange between the phases in the mixture. The separation length between the frontal Champatis and Silam grains increases exceptionally as it does between the main body and the exclusively Silam-covered tremendously long tail of the flow in the inclined portion of the channel. These results may be useful in better understanding the phase separation, superwide-spreading and hypermobility of some geological flows, including fragmented rock avalanches, probably helping resolve some relevant standing challenges.

VertexWiseR: a package for simplified vertex-wise analyses of whole-brain and hippocampal surfaces in R

Abstract Currently, whole-brain vertex-wise analyses on brain surfaces commonly require specially configured operating systems/environments to run and are largely inaccessible to R users. As such, these analyses are inconvenient to execute and inaccessible to many aspiring researchers. To address these limitations, we present VertexWiseR, a user-friendly R package, to run cortical and hippocampal surface vertex-wise analyses, in just about any computer, requiring minimal technical expertise and computational resources. The package allows cohort-wise anatomical surface data to be highly compressed into a single, compact, easy-to-share file. Users can then run a range of vertex-wise statistical analyses with that single file without requiring a special operating system/environment and direct access to the preprocessed file directories. This enables the user to easily take the analyses ‘offline’, which would be highly appropriate and conducive in classroom settings. This R package includes a conventional suite of tools for extracting, manipulating, analysing, and visualizing vertex-wise data, and is designed to be easy for beginners to use. Furthermore, it also contains novel or advanced functionalities such as hippocampal surface analyses, meta-analytic decoding, threshold-free cluster enhancement, and mixed effects models that would appeal to experienced researchers as well. In the current report, we showcase these functionalities in the analyses of two publicly accessible datasets. Overall, our R package opens up new frontiers for the R’s user base/community and makes such neuroimaging analyses accessible to the masses.

Reduction of aortic stiffness in newly diagnosed persons with HIV-infection: modifiable vascular dysfunction after antiretroviral therapy?

Abstract Background People living with HIV (PLWH) are at an increased risk of cardiovascular disease (CVD), which is underestimated by contemporary risk stratification systems[1]. Subclinical cardiovascular abnormalities may be present at the time of HIV diagnosis and serve as potential substrate for future CVD. Aortic stiffness, as measured with pulse wave velocity (PWV), is a validated predictor of CVD [2,3] and has been shown to be elevated in PLWH at the time of HIV diagnosis compared to HIV-uninfected persons[4]. Purpose To prospectively assess the influence of contemporary antiretroviral therapy (ART) on aortic stiffness in a group of newly diagnosed PLWH in a low- to middle-income setting. Methods A group of ART naïve PLWH with modest cardiovascular risk and free from known CVD, was recruited at the time of HIV diagnosis from the Western Cape Province of South Africa. Aortic stiffness was measured using carotid-femoral PWV on a commercially available device that simultaneously measured the carotid and femoral waveforms on a supine patient in a temperature-controlled room utilising established methodology[4]. The algorithmically-calculated time delay between the upstroke of the carotid and femoral wave-forms provided the transit time (TT). Carotid femoral path distance (path length) was measured using surface anatomy. PWV was calculated as direct path length divided by TT. Aortic distensibility was expressed according to the Bramwell-Hill equation as 3.57/PWV(squared)[5]. ART was initiated and PWV was re-evaluated 9 months later. Results Seventy-three participants completed follow-up and were included. The cohort was relatively young (mean age 32±7 years) with good female representation (n=33, 45%). Most received tenofovir/lamivudine/dolutegravir (n=71, 97%) Half of the group smoked cigarettes. Two participants were controlled hypertensives, and two participants had metabolic syndrome. A significant decrease in PWV (with scaling factor of 0.8) was observed at 9 months of ART (5.93 ±1.0 vs. 5.69 ±1.0 m/s; p=0.01). Aortic distensibility increased significantly as well (0.20 [IQR: 0.16 to 0.26] vs. 0.21 [IQR: 0.19 to 0.27] mmHg-1; p=0.02). Conclusion Improvement in aortic stiffness was observed in a group of newly diagnosed PLWH after 9 months of ART-initiation. This provides evidence of a modifiable component of vascular dysfunction and, in turn, cardiovascular risk with the use of contemporary ART at 9 months. It is unknown if this effect will be sustained long-term. The use of aortic stiffness (alone or in combination with other parameters) as a predictor of cardiovascular outcomes in the ART era requires further study.Abstract figureAbstract table

In-silico insights into personalised therapy selection of anti-arrhythmic drugs and ablation using patient-specific biatrial models for atrial fibrillation

Abstract Introduction Current treatment approaches for Atrial Fibrillation (AF) often lack personalisation, adopting a one-size-fits-all paradigm that disregards inter-patient diversity and its unique interplay with therapeutic responses. In-silico drug trials have demonstrated some value in the personalisation of care; however, their integration with patient-specific anatomical data and the synergistic effects of combined therapies remain unknown. Purpose To evaluate the patient-specific response to anti-arrhythmic drugs (AADs) and their efficacy both individually and in combination with pulmonary vein isolation (PVI) using personalised biatrial models created from imaging data. Methods Patient-specific biatrial models (n=70) were constructed from late gadolinium-enhanced MRI images by manual segmentation from the Atrial Segmentation Challenge (2018) dataset (Fig.1A). Models were pre-processed with landmark selection, regional assignment, and fibre allocation before simulations (Fig.1B). PVI was modelled as electrically inert rings around the pulmonary veins (Fig.1C) and AADs were administered via ionic modulation within CARPentry software (Fig.1D). Four commonly used AADs were evaluated: vernakalant, acute and chronic amiodarone, flecainide, and digoxin. Finite element simulations were performed with the addition of AADs, both individually and in combination with PVI, to evaluate their efficacy in terminating AF (Fig.2A). These simulations were post-processed to produce phase singularity (PS) density maps to evaluate changes in wavefront patterns and locations of re-entry and wavefront break-up (Fig.2B). Results The combination of digoxin with PVI and digoxin alone demonstrated the highest effectiveness in terminating AF, both achieving success in 68.4% of cases (95% CI: 67.5% to 89.3%, p≤0.0001). This efficacy significantly exceeded that of other AADs used either alone or in combination with PVI (15.8%-57.9%), whereas PVI alone demonstrated 0% efficacy (p≤0.05). The combined therapy exhibited a multi-faceted localisation pattern (Fig.2A), with AADs initially redistributing PSs to the pulmonary veins and left atrial appendage. This redistribution resulted in synergistic effects in terminating AF episodes in 52.6% more cases when combined with PVI (Fig.2B). Comparative analyses showed an inverse correlation between baseline PS density count and anatomical surface area with AF termination across all treatments, with significant correlations observed with vernakalant alone (rho=-0.55, p≤0.05) and combined with PVI (rho=-0.77, p≤0.05). Conclusions This study demonstrates the significance of personalised treatment selection in optimising patient outcomes. Combined therapeutic interventions have shown synergistic benefits in AF termination, surpassing individual therapies in this patient-specific model cohort. This shows the translational potential of using patient-specific stratification to inform treatment selection.Biatrial model generationAF therapeutic simulation and processing

Neurosurgical skills conference for medical students: A before and after study.

Undergraduate conferences may improve exposure to neurosurgery among medical students. Hence, this study aimed to evaluate the effect of a neurosurgical skills conference on medical students' comprehension and perceptions of the specialty. A before-and-after (BA) study design was employed to assess the effects of a conference that integrated presentations with hands-on sessions. Practical workshops covered craniotomy, spinal fixation, surface anatomy, intracranial pressure (ICP) monitoring, basic surgical skills, and microsurgical simulation. Pre-conference and post-conference surveys, utilizing Likert scales, gauged participants' attitudes, prior neurosurgical exposure, and understanding of neurosurgical skills. Statistical analysis was conducted on dichotomized responses. Thirty-one participants completed both surveys, with the majority being 1st and 2nd-year medical students. Among the participants, 58.1% were female, and 77.4% identified with BAME ethnicities. Following the conference, there was a notable increase in comprehension regarding neurosurgical careers (from 58.1% to 96.8%, P < 0.001) and training criteria (from 22.6% to 93.5%, P < 0.001). The conference enhanced knowledge of indications for craniotomy (P < 0.001), ICP monitoring (P < 0.001), and spinal fixation (P < 0.001). Participants reported improved understanding of the steps involved in craniotomy (P < 0.001), familiarity with basic cranial surgical surface anatomy (P < 0.001), and confidence in performing basic surgical instrument ties (P < 0.001). Although interest in pursuing a career in neurosurgery remained high (from 87.1% to 90.3%, P = 1.000), a majority of participants, both BA the conference, expressed concerns about the impact on personal life (from 58.1% to 64.5%, P = 0.774). This study underscores the role of undergraduate mixed-method conferences in augmenting understanding of neurosurgery and nurturing early interest.

ShapeMed-Knee: A Dataset and Neural Shape Model Benchmark for Modeling 3D Femurs.

Analyzing anatomic shapes of tissues and organs is pivotal for accurate disease diagnostics and clinical decision-making. One prominent disease that depends on anatomic shape analysis is osteoarthritis, which affects 30 million Americans. To advance osteoarthritis diagnostics and prognostics, we introduce ShapeMed-Knee, a 3D shape dataset with 9,376 high-resolution, medical-imaging-based 3D shapes of both femur bone and cartilage. Besides data, ShapeMed-Knee includes two benchmarks for assessing reconstruction accuracy and five clinical prediction tasks that assess the utility of learned shape representations. Leveraging ShapeMed-Knee, we develop and evaluate a novel hybrid explicit-implicit neural shape model which achieves up to 40% better reconstruction accuracy than a statistical shape model and two implicit neural shape models. Our hybrid models achieve state-of-the-art performance for preserving cartilage biomarkers (root mean squared error ≤ 0.05 vs. ≤ 0.07, 0.10, and 0.14). Our models are also the first to successfully predict localized structural features of osteoarthritis, outperforming shape models and convolutional neural networks applied to raw magnetic resonance images and segmentations (e.g., osteophyte size and localization 63% accuracy vs. 49-61%). The ShapeMed-Knee dataset provides medical evaluations to reconstruct multiple anatomic surfaces and embed meaningful disease-specific information. ShapeMed-Knee reduces barriers to applying 3D modeling in medicine, and our benchmarks highlight that advancements in 3D modeling can enhance the diagnosis and risk stratification for complex diseases. The dataset, code, and benchmarks are freely accessible.

Exploring the anatomy of Linguatula serrata using micro-computed tomography

Micro-computed tomography (micro-CT) is an emerging tool in parasitology that can assist in analysing morphology and host-parasitic interactions. It is a non-destructive, cross-sectional imaging technique that offers good resolution and the ability to create three-dimensional (3D) reconstructions. Here, we used micro-CT to study Linguatula serrata, which is a zoonotic pentastome parasite that infects dogs and ruminants throughout the world. The aims of this study were to describe the internal and external anatomy of adult L. serrata specimens using micro-CT, and to describe and compare specimens stained with 0.3% phosphotungstic acid (PTA) and 1% iodine (I2). Ten adult L.serrata specimens were subjected to micro-CT examination. The specimens were fixed in 70% ethanol and stained with 0.3% PTA or 1% I2. Both stains offered good tissue contrast. The main identifying external features of L. serrata (hooks, mouth, buccal cadre) were clearly visible. Virtual sections and 3D reconstructions provided a good overview of the coelomic cavity, with visualisation of the digestive tract, nervous system, and male and female reproductive organs. These micro-CT images and morphological descriptions may serve as an anatomical reference for L. serrata, in particular, the internal anatomy which has not been described in recent years.

Conformal immunomodulatory hydrogels for the treatment of otitis media

Otitis media (OM), a condition stemming from the proliferation of various bacteria within the tympanic cavity (TC), is commonly addressed through the administration of ofloxacin (OFL), a fluoroquinolone antibiotic. Nevertheless, the escalating issue of antibiotic resistance and the challenge of drug leakage underscore the exploration of an alternative, more effective treatment modality in clinical practice. Here, we introduce a simple and easily implementable fluid-regulated strategy aimed at delivering immunomodulatory hydrogels into the TC, ensuring conformal contact with the irregular anatomical surfaces of the middle ear cavity to more effectively eliminate bacteria and treat OM. This innovative strategy exhibits expedited therapeutic process of antibiotic-resistant, acute and chronic OM rats, and significant reductions in the severity of tympanic membrane (TM) inflammation, residual bacteria within the TC (0.12 *105 CFU), and the thickness of TM/TC mucosa (17.63/32.43 μm), as compared to conventional OFL treatment (3.6, 0.76 *105 CFU, 48.70/151.26 μm). The broad-spectrum antibacterial and antibiofilm properties of this strategy against a spectrum of OM pathogens are demonstrated. The strategy is validated to bolster the host’s innate immune response through the stimulation of antibacterial protein synthesis, macrophage proliferation and activation, thereby accelerating bacterial eradication and inflammation resolution within the TC. This facile, cost-effective and in vivo degradable technology exhibits promising prospects for future clinical implementation.

Doses of Botulinum Toxin in Cervical Dystonia: Does Ultrasound Guidance Change Injection Practices?

Cervical dystonia is widely understood to benefit from botulinum toxin injections. The injection practices may be influenced by specific factors, including the method of injection. Three main guidance methods can be used: palpation of anatomical landmarks, ultrasound, and electromyography. We investigated how target muscles and doses of botulinum toxin were modified after the transition from surface anatomy (non-guided) to ultrasound (US-guided), in patients with cervical dystonia. We also determined the long-term dose trend. We studied a group of 82 patients, who received non-guided injections (median: 16.5 cycles/5.1 years) followed by US-guided injections (median: 12.0 cycles/3.8 years). More muscles, and especially deep muscles, were injected during the US-guided period. The total dose and number of injected muscles were higher when US guidance was used, but the mean dose per muscle was lower. Over the long term, the total dose stabilized, and the mean dose per muscle decreased during the US-guided period. According to our results, the guidance method has a strong impact on the botulinum toxin injection strategy in cervical dystonia (target muscles and dose). Also, the treatment appeared more stable when using US guidance; this could be explained by the good precision of such injections.

Transitioning through drawing

‘Transitioning through drawing’ is a series of works on paper that explore the value and role of drawing to alleviate the emotional distress and isolation experienced by people experiencing illness, while also facilitating opportunities for contemplation and inquiry into the clinical procedures through an aesthetic lens. This series reflects a practice-led enquiry that stemmed from the artist’s exploration of various forms of drawing within their creative practices. Drawing experiments included marks made by oil paint across water and movements of the body on an inked glass surface, both of which created imprints on large sheets of paper. These marbled surfaces and body monoprints became the foundation for further additions, including forms, surface marks and textures. The phenomenological nature of these drawings, combined with the physical act of creating them, mirrors the diagnostic process of searching for disease and decay within the body through medical imaging. Through this artistic lens, the drawings evoke the shared experience of vulnerability.

Impact of Hormone Therapy on Serum Lipids in Transgender People

The term “Transgender” is used to describe individuals whose gender identity is different from their external sexual anatomy at birth. The number of people identifying as transgender has increased in recent years, and consequently, the number of gender affirmation surgeries and the use of hormonal therapies has also increased. A wide range of hormonal therapies has emerged considering the target population, age, and final outcomes, and as such these are becoming increasingly developed and complex in order to be the most appropriate for each individual. However, the side effects of these therapies remain to be fully understood. Therefore, this review aims to assess the impact of hormone therapy, in both transgender men and women of different ages, on the lipid profile. From the studies analyzed, it is possible to conclude that there is a relationship between hormone therapy and the lipid profile, with different outcomes between transgender men and women. There is a reduction in cardiovascular risk for transgender women as opposed to transgender men, in whom cardiovascular risk seems to increase due to lipid changes. It is now necessary to understand the mechanisms involved in order to reduce the consequences of these therapies and promote positive health outcomes.

Are the Umbilicus and Iliac Crests Truly at the Level of L4 to L5? A Computed Tomography-Based Study of Surface Anatomy of the Anterior Lumbar Spine.

This study aimed to determine whether the iliac crests are truly at the level of L4 to L5, accounting for patient demographic and anthropometric characteristics. We measured the umbilicus and iliac crests relative to the lumbar spine using computed tomography of patients without spinal pathology, accounting for the influences of patient height, weight, body mass index (BMI), sex, race, and ethnicity. A total of 834 patients (391 men and 443 women) were reviewed. The location of the umbilicus relative to the lumbar spine demonstrated a unimodal distribution pattern clustered at L4, while the iliac crests were most frequently located from L4 to L5. Iliac crests were located above the L4 to L5 disc space 26.5% of the time. Iliac crests were located at the L4 to L5 disc space 29.8% of the time. No correlations were observed between the umbilicus and iliac crests with patient height, weight, or BMI. There was no difference in the location of the umbilicus with respect to patient sex, race, and ethnicity. The locations of the iliac crests were cephalad in women compared with men and in Hispanics compared with African American, Caucasian, and Asian patients. The iliac crests were located above the level of the L4 to L5 disc space approximately 26% of the time. The umbilicus is most frequently at the level of the L4 vertebral body. Patient height, weight, and BMI do not influence the location of the umbilicus or the iliac crests relative to the lumbar spine. Patient sex and ethnicity influence the location of the iliac crests but not the umbilicus relative to the lumbar spine. Modern neurosurgical techniques require clearance of the iliac crests during anterior and anterolateral approaches. Understanding the level of the iliac crests is crucial in planning for transpsoas fusion approaches.

Anatomical description of a pygmy sperm whale, Kogia breviceps (Cetacea: Kogiidae), pre-term calf using CT scan and 3D reconstructions.

Little is known about the biology of pygmy sperm whales, Kogia breviceps (De Blainville, 1838), being that most anatomical descriptions for the species derive from necropsy after stranding or from osteological material preserved in museums. This species is rarely seen despite its wide distribution, and its reproductive behaviour is still being investigated. The eventual occurrence of pregnant female strandings and the collection and description of foetuses can give clues about the organisms' mostly unknown early development. However, this type of biological material is extremely rare, limiting anatomical analysis due to the risk of damage or loss. Here, we describe the external and internal anatomy of an 84 cm long K. breviceps foetus. The methods utilised were non-intrusive, meaning that no incisions were made on the specimen. The foetus was analysed using computed tomography images and a three-dimensional reconstruction of the skeleton. A great number of features were observed, such as axial and appendicular skeletal structures, internal organs, echolocation apparatus and umbilical cord, as well as diagnostic characters of the species, such as the asymmetrical skull, spermaceti chamber and false gill pigmentation. We suggest that more specimens on different stages of development should be analysed by the same technique, as well as further comparison with specimens from other taxa, in order to facilitate more comparative studies on embryonic and foetal development of cetaceans.

Endocranial anatomy and phylogenetic position of the crocodylian Eosuchus lerichei from the late Paleocene of northwestern Europe and potential adaptations for transoceanic dispersal in gavialoids.

Eosuchus lerichei is a gavialoid crocodylian from late Paleocene marine deposits of northwestern Europe, known from a skull and lower jaws, as well as postcrania. Its sister taxon relationship with the approximately contemporaneous species Eosuchus minor from the east coast of the USA has been explained through transoceanic dispersal, indicating a capability for salt excretion that is absent in extant gavialoids. However, there is currently no anatomical evidence to support marine adaptation in extinct gavialoids. Furthermore, the placement of Eosuchus within Gavialoidea is labile, with some analyses supporting affinities with the Late Cretaceous to early Paleogene "thoracosaurs." Here we present novel data on the internal and external anatomy of the skull of E. lerichei that enables a revised diagnosis, with 6 autapormorphies identified for the genus and 10 features that enable differentiation of the species from Eosuchus minor. Our phylogenetic analyses recover Eosuchus as an early diverging gavialid gavialoid that is not part of the "thoracosaur" group. In addition to thickened semi-circular canal walls of the endosseous labyrinth and paratympanic sinus reduction, we identify potential osteological correlates for salt glands in the internal surface of the prefrontal and lacrimal bones of E. lerichei. These salt glands potentially provide anatomical evidence for the capability of transoceanic dispersal within Eosuchus, and we also identify them in the Late Cretaceous "thoracosaur" Portugalosuchus. Given that the earliest diverging and stratigraphically oldest gavialoids either have evidence for a nasal salt gland and/or have been recovered from marine deposits, this suggests the capacity for salt excretion might be ancestral for Gavialoidea. Mapping osteological and geological evidence for marine adaptation onto a phylogeny indicates that there was probably more than one independent loss/reduction in the capacity for salt excretion in gavialoids.

A new species of Anthopleura (Cnidaria: Anthozoa: Actiniaria) from the Mexican Pacific

Anthopleura is one of the most speciose genera within the family Actiniidae. This genus is particularly characterized by its members having both verrucae on the column and acrorhagi on the margin. In the region of the Baja California Peninsula, in the Mexican Pacific, six species of Anthopleura have been documented, which are relatively well defined by their morphological characteristics and coloration patterns. During recent visits to the intertidal zone of Cerritos, in Baja California Sur, we found individuals of Anthopleura displaying a variety of colorations that do not agree with known species for the region. We collected and examined specimens of four morphotypes of Anthopleura, analyzing them by integrating information about their external and internal anatomy, as well as their cnidome. Additionally, we obtained and analyzed genetic sequences from mitochondrial and nuclear markers through phylogenetic analyses. Our results reveal that the four morphotypes belong to a single, and undescribed species of Anthopleura. We provide a detailed description of the species Anthopleura variata sp. nov., which is characterized by a variety of coloration patterns, as well as having a circumscribed, palmate, and pedunculate marginal sphincter muscle, harboring zooxanthellae, and lacking directive mesenteries, among other characteristics. Anthopleura variata sp. nov. is the 49th species in the genus and the seventh species of Anthopleura documented for the Mexican Pacific.

53385 Visual library of surface anatomy to establish reproducible, accurate, and precise anatomic site descriptions.

53385 Visual library of surface anatomy to establish reproducible, accurate, and precise anatomic site descriptions.