Comparative microscopic anatomy of Schizomida - 1. Segmental axial musculature and body organization.

Schizomida is an enigmatic group of arachnids that is traditionally considered the dwarfed sister to Thelyphonida. Schizomids are of interest for evolutionary morphology, because they show a number of features like a tripartite prosoma dorsal shield (pro-, meso-, metapeltidium), formation of three sterna, a complex prosoma-opisthosoma transition and a metasoma. By analyzing the body organization of Schizomida and comparing it to Thelyphonida and other arachnids, this article provides evidence for independent evolution of some of these features in Schizomida. This supports the idea that, among arachnids, multiple and independent evolutionary pathways have resulted in similar morphologies, that conventionally have been considered shared similarities. - The analysis of serial microscopic sections and µCT-imaging of segmental indicator muscles of the prosoma evidences that the propeltidium covers prosoma segments 0-4, and the metapeltidium covers segments 5 and 6. The mesopeltidium is a dorsolateral sclerotization of the pleural membrane, not assigned to a segment, and therefore not a tergite. The topographic association of segmental musculature and sclerites of the tripartite dorsum of the prosoma differs from other taxa with such external body organization, e.g., Palpigradi and Solifugae, suggesting independent evolutionary origin. - The prosoma-opisthosoma transition integrates the first opisthosoma segment into the prosoma. The sternite of the first opisthosoma segment forms the metasternum between the coxae of the fourth pair of walking legs. The morphology of the prosoma-opisthosoma transition is similar to Uropygi and Amblypygi, but is less complex. - The morphology of the metasoma (opisthosoma segments X-XII) of Schizomida and Thelyphonida differs from that of all other arachnids carrying a metasoma, thus providing support for multiple independent evolutionary origins of metasomata.

Comparative anatomy of siphons in tellinoidean clams (Bivalvia, Tellinoidea).

Siphons are tubular organs formed by fusion and posterior extension of the marginal mantle folds. They are supposed to have performed key roles in the evolution of bivalves by enabling these animals to occupy several ecological niches. However, anatomical details of these organs are scarce for one of the most diverse lineages of tropical bivalves, the superfamily Tellinoidea. We investigated the siphonal morphology of 15 species, sampling five tellinoidean families, by integrating scanning electron microscopy, confocal microscopy, and histology. The siphons revealed variations in length, pigmentation, tentacles, papillae, and number of nerve cords. Due to the presence of sensorial structures, such as papillae and tentacles, we reclassify the siphons of Tellinoidea from type A to A+. Additional anatomical patterns were identified at family and genus levels. For example, the incurrent siphon shorter than the excurrent and 24 tentacles are putative synapomorphies of Donacidae. We also highlight shared siphonal traits between Donacidae and Solecurtidae as well as between Semelidae and Tellinidae. In addition, our data support the idea of Psammobiidae as a paraphyletic lineage. Overall, we provide an extensive comparative data set on siphonal traits with significant relevance for bivalve taxonomy, functional anatomy, and evolutionary investigations.

A life dedicated to research and ideal: Johannes Müller between empirical universality and idealistic vitalism mirrored in lecture notes from 1851.

Until the mid-nineteenth century, "physiology" was a comprehensive theory of life, expounded and shaped by Johannes P. Müller (1801-1858). Biologists and medical doctors still refer to him today. In the summer term of 1851, Müller gave a lecture on the Comparative Anatomy of animals. This lecture was attended and recorded by Ernst Zeller (1830-1902), a future physician and zoologist, and has recently been published together with a German transcript. In this paper, we situate Johannes Müller within the intellectual history of his time. Through his "empirical idealism," we show how he opposed the speculative tendencies of the romantic understanding of nature, the emerging evolutionism, and the growing splits in the natural sciences. Müller focused on recognizing living nature as a whole and realizing ideal "phenomena" through his empirical research. He considered the notion of the soul of the world. Müller's lecture transcript serves as a poignant testament to German scientific culture in the mid-nineteenth century, a few years before the publication of Darwin's Origin of Species. It also provides valuable insights into the self-contained epistemological foundations of morphology.

Explanation, teleology, and analogy in natural history and comparative anatomy around 1800: Kant and Cuvier.

This paper investigates conceptions of explanation, teleology, and analogy in the works of Immanuel Kant (1724-1804) and Georges Cuvier (1769-1832). Richards (2000, 2002) and Zammito (2006, 2012, 2018) have argued that Kant's philosophy provided an obstacle for the project of establishing biology as a proper science around 1800. By contrast, Russell (1916), Outram (1986), and Huneman (2006, 2008) have argued, similar to suggestions from Lenoir (1989), that Kant's philosophy influenced the influential naturalist Georges Cuvier. In this article, I wish to expand on and further the work of Russell, Outram, and Huneman by adopting a novel perspective on Cuvier and considering (a) the similar conceptions of proper science and explanation of Kant and Cuvier, and (b) the similar conceptions of the role of teleology and analogy in the works of Kant and Cuvier. The similarities between Kant and Cuvier show, contrary to the interpretation of Richards and Zammito, that some of Kant's philosophical ideas, whether they derived from him or not, were fruitfully applied by some life scientists who wished to transform life sciences into proper sciences around 1800. However, I also show that Cuvier, in contrast to Kant, had a workable strategy for transforming the life sciences into proper sciences, and that he departed from Kant's philosophy of science in crucial respects.

Comparative Anatomy of the Vomeronasal Organ (VNO) in Sheep (Ovis aries) and Dogs (Canis familiaris) with Simple Reference to its Histological Structure and Vasculature Supply

SUMMARY: The vomeronasal organ (VNO) is located in the anteroinferior part of the nose and the accessory olfactory organ in mammals which is responsible of sense of smell. This study aims to compare the macro and microanatomical structure of the VNO between sheep and dogs. In the current study, we used ten adult slaughtered sheep and ten adult synchronized dogs with different sexes ages 1-2 years. The head of both animals were preserved in 10 % formalin for one week. This study shows in both animals, the VNO occupies the same position in the cavity of the vomer bone and the same relationship in the cranial part of the nasal cavity. Furthermore, the VNO is divided into three parts based on shape that are the rostral, central, and caudal part. The results show the VNO in sheep has a (U) shape and is opened dorsolaterally. It has a small and narrow cavity. It is long 6 cm long, and it has different diameters on its course. In comparison, the vomeronasal organ in dogs is very developed and has a (J) shape. It has a large and long cavity and ends at the fourth molar. Its length is about 10 cm, and it has one diameter on its course. The VNO receives the blood supply from the sphenopalatine and caudal palatine arteries. The present study shows main differences between sheep and dogs VNO in which the structure of vomeronasal bone between the sheep and dog is completely different. The finding will illustrate fundamental differences and provide specific structural differences between the two species.

El órgano vomeronasal (OVN) se encuentra en la parte anteroinferior de la nariz y el órgano olfativo accesorio en los mamíferos es responsable del sentido del olfato. Este estudio tuvo como objetivo comparar la estructura macro y microanatómica del OVN entre ovejas y perros. En el estudio utilizamos diez ovejas adultas y diez perros adultos de diferentes sexos con edades de 1 a 2 años. Las cabezas de ambos animales se conservaron en formol al 10 % durante una semana. Este estudio mostró que en ambos animales, el OVN ocupa la misma posición en la cavidad del hueso vómer y la misma relación en la parte craneal de la cavidad nasal. Según su forma el OVN se divide en tres partes: rostral, central y caudal. Los resultados mostraron que el OVN en las ovejas tiene forma de (U) y está abierto dorsolateralmente. Presenta una cavidad pequeña y estrecha. Además, tiene una longitud de 6 cm y tiene diferentes diámetros en su recorrido. En comparación, el órgano vomeronasal en los perros está muy desarrollado y tiene forma de (J). Presenta una cavidad grande y larga y termina en el cuarto molar. Su longitud es de unos 10 cm y tiene un diámetro distinto en su recorrido. El OVN recibe el suministro de sangre de las arterias esfenopalatina y palatina caudal. El presente estudio muestra las principales diferencias entre el OVN de ovejas y perros en el que la estructura del hueso vomeronasal entre estos dos animales es completamente diferente. Además, los hallazgos ilustran diferencias fundamentales y determinan diferencias estructurales específicas entre las dos especies.

Of mice (dogs, horses, sheep) and men: A novel comparative anatomy dissection course in a United Kingdom university.

At the University of Bristol, we established a novel dissection course to complement our anatomy degree. Students enrolled in this undergraduate course are trained as comparative anatomists, with equal time given to both human and veterinary anatomy. Historically, students opted to dissect either human or veterinary donors as part of the course. To fully reflect the comparative nature of the degree, the dissection course was redesigned so students could dissect both human and veterinary specimens as part of the same course. This facilitated a wide-ranging experience of anatomy, encouraging detailed knowledge of a multitude of species and allowing for multifaceted anatomy graduates to be ready for employment in a wide and competitive job market. Across three iterations of the amended version of the course, median marks ranged from 58.7% to 62.0%, with between 22 and 39 students enrolled. In comparison to the course prior to the introduction of the change, median marks ranged from 59.8% to 62.8%, with between 16 and 24 students enrolled. There was no significant difference between marks before or after the introduction of the concurrently comparative aspect. This paper describes the course, with learning materials and assessments considered, along with some reflection on its value. The course offers benefits to students by widening their perspective on anatomical knowledge and making them more equipped for the job market. It also broadens their understanding of form-function relationships. However, student feedback implied that having the choice between human or veterinary dissection was preferable, and this may outweigh the perceived benefits of the course.

Comparative anatomy of the spinneret musculature in cribellate and ecribellate spiders (Araneae).

Silk production is a prominent characteristic of spiders. The silk is extruded through spigots located on the spinnerets, which are single- to multimembered paired appendages at the end of the abdomen. Most extant spiders have three pairs of spinnerets, and in between either a cribellum (spinning plate) or a colulus (defunct vestigial organ), dividing these spiders into cribellate and ecribellate species. Previous research has shown that cribellate and ecribellate spiders differ not only in the composition of their spinning apparatus but also in the movements of their spinnerets during silk spinning. The objective of this study was to determine whether the differences in spinneret movements are solely due to variations in spinneret shape or whether they are based on differences in muscular anatomy. This was accomplished by analyzing microcomputed tomography scans of the posterior abdomen of each three cribellate and ecribellate species. It was found that the number of muscles did not generally differ between cribellate and ecribellate species, but varied considerably between the species within each of these two groups. Muscle thickness, particularly of the posterior median spinneret, varied slightly between groups, with cribellate spiders exhibiting more robust muscles, possibly to aid in the combing process during cribellar thread production. Interestingly, the vestigial colulus still possesses muscles, that can be homologized with those of the cribellum. This exploration into spinneret anatomy using microcomputed tomography data reveals that despite being small appendages, the spider spinnerets are equipped with a complex musculature that enables them to perform fine-scaled maneuvers to construct different fiber-based materials.

Comparative anatomy, histochemistry and phytochemistry of three species of the genus Tarenaya Raf.

This study addresses the morphological similarities and taxonomic complexity of the genus Tarenaya Raf. of the family Cleomaceae Bercht. & J. Presl as well as the medicinal use of their species. The research compares potential anatomical diagnostic characters of the vegetative organs of species Tarenaya aculeata, Tarenaya diffusa, and Tarenaya spinosa to determine authenticity parameters. The study also carried out histochemical and phytochemical analyses of leaf blades to explore the medicinal use of these species. Semipermanent slides containing cross sections of the stems, petioles, and leaf blades, as well as paradermal sections of leaf blades, were prepared. The analyses were carried out in light and polarized optical microscopy. The histochemical analysis included different reagents depending on the target metabolite, which were analyzed by optical and fluorescence microscopy. Phytochemical tests of the methanolic extracts of the leaves were performed using thin layer chromatography. Anatomical characterization showed the characters of general occurrence in the family Cleomaceae and those that allow the differentiation of T. aculeata, T. diffusa, and T. spinosa. Histochemistry revealed the synthesis and/or storage sites of the metabolites and phytochemical tests; it was possible to observe the presence of different metabolites. The results bring comparative data on the anatomical and histochemical characterization of the species, thus increasing the taxonomic knowledge of the genus Tarenaya. RESEARCH HIGHLIGHTS: The comparative anatomy of three Tarenaya from Brazil was studied. Anatomical differences in different vegetative organs differ species. Differences in histochemistry and phytochemistry.

True grit? Comparative anatomy and evolution of gizzards in fishes.

Gut morphology frequently reflects the food organisms digest. Gizzards are organs of the gut found in archosaurs and fishes that mechanically reduce food to aid digestion. Gizzards are thought to compensate for edentulism and/or provide an advantage when consuming small, tough food items (e.g., phytoplankton and algae). It is unknown how widespread gizzards are in fishes and how similar these structures are among different lineages. Here, we investigate the distribution of gizzards across bony fishes to (1) survey different fishes for gizzard presence, (2) compare the histological structure of gizzards in three species, (3) estimate how often gizzards have evolved in fishes, and (4) explore whether anatomical and ecological traits like edentulism and microphagy predict gizzard presence. According to our analyses, gizzards are rare across bony fishes, evolving only six times in a broad taxonomic sampling of 51 species, and gizzard presence is not clearly correlated with factors like gut length or dentition. We find that gizzard morphology varies among the lineages where one is present, both macroscopically (presence of a crop) and microscopically (varying tissue types). We conclude that gizzards likely aid in the mechanical reduction of food in fishes that have lost an oral dentition in their evolutionary past; however, the relative scarcity of gizzards suggests they are just one of many possible solutions for processing tough, nutrient-poor food items. Gizzards have long been present in the evolutionary history of fishes, can be found in a wide variety of marine and freshwater clades, and likely have been overlooked in many taxa.

The comparative anatomy of the petrosal bone and bony labyrinth of four small-sized deer.

Here we provide complete 3D reconstructions of the petrosal bone and bony labyrinth of four kinds of small-sized deer (Elaphodus cephalophus, Muntiacus reevesi, Muntiacus muntjak, Hydropotes inermis) based on high-resolution CT scanning, and select one musk deer (Moschus moschiferus) as a comparative object. The petrosal bone and bony labyrinth of E. cephalophus are illustrated for the first time, as well as the petrosal bones of M. reevesi and H. inermis. Some morphological characters of petrosal bone and bony labyrinth can be used to distinguish the above-mentioned species. For example, M. moschiferus shows a prominent transpromontorial sulcus and a ventral basicapsular groove on the petrosal bone; there is a bifurcate cochlear aqueduct on the bony labyrinth of E. cephalophus; there is a distinct fusion between the lateral and posterior semicircular canals on the bony labyrinth of H. inermis. Meanwhile, there are some intraspecific variations on the subarcuate fossa, the tegmen tympani, the cochlear aqueduct, as well as the endolymphatic sac. Our results further confirm that the petrosal bone and bony labyrinth have enormous potential for taxonomy. This work will provide new anatomical data for the phylogenetic study of ruminants in the future, and it will be very practical to identify the isolated ruminants' petrosal bones that are frequently unearthed from paleontological or archeological sites.

Anatomía Comparada del Bazo de la Rata Blanca (Rattus norvegicus albinus), Una Revisión de la Literatura / Comparative Anatomy of the Spleen of the White Rat, (Rattus norvegicus albinus) a Literature Review

El bazo es el órgano linfático intraperitoneal más grande del organismo, presentando dos funciones principales: defensiva, mediante respuesta inmunitaria y filtración sanguínea. El objetivo de la presente revisión, fue obtener información actualizada sobre la anatomía del bazo de la rata albina (Rattus norvegicus albinus) y comparativa con la anatomía del bazo humano, perro, gato y cerdo, al representar las principales especies de importancia en la medicina, medicina veterinaria y en las ciencias biomédicas. Se realizó una búsqueda de material bibliográfico actualizado en diferentes sitios web científicos. Es así como, se revisaron 71 fuentes bibliográficas, en su gran mayoría artículos científicos (31), libros de anatomía humana y veterinaria (17), artículos especializados (17) y tesis (6). En general existe consenso, sobre la descripción anatómica del bazo, el cual se sitúa en la región hipocondriaca izquierda del abdomen, entre el fondo del estómago y el diafragma, irrigado por la arteria y vena esplénica. Se evidenció que existen similitudes en aspectos macroscópicos, al comparar el bazo de la rata blanca, con el bazo de otras especies (funcionalidad, peso relativo, ubicación topográfica). En aspectos microscópicos, el bazo en humanos y otros mamíferos se compone de estroma, además de parénquima, constituido a su vez por pulpa blanca y roja. En particular, existen diferencias entre el bazo de rata, humano, gato, perro y cerdo, en formas, tamaños y aspectos microscópicos, relacionados con la microcirculación e inmunidad. Mientras que existen semejanzas en procesos patológicos y respuestas a tratamientos farmacológicos y clínicos. Por lo anteriormente expuesto, se concluye que la rata albina constituye un buen modelo biológico, específicamente en aspectos anatómicos microscópicos del bazo de tipo inmunológico. Mientras que el bazo de cerdo es mejor comparativamente, en estudios anatómicos macroscópicos de tipo quirúrgicos, resultando ambos extrapolables, especialmente a la medicina humana.

SUMMARY: The spleen is the largest intraperitoneal lymphatic organ of the body, presenting two main functions: defensive, through immune response and blood filtration. The objective of the present review was to obtain updated information on the anatomy of the spleen of the albino rat (Rattus norvegicus albinus) and to compare it with the anatomy of the human, dog, cat and pig spleen, representing the main species of importance in medicine, veterinary medicine and biomedical sciences. A search for updated bibliographic material was carried out in different scientific websites. Thus, 71 bibliographic sources were reviewed, mostly scientific articles (31), human and veterinary anatomy books (17), specialized articles (17) and theses (6). In general, there is consensus on the anatomical description of the spleen, which is located in the left hypochondriac region of the abdomen between the fundus of the stomach and the diaphragm, irrigated by the splenic artery and vein. It was evidenced that there are similarities in macroscopic aspects when comparing the spleen of the white rat with the spleen of other species (functionality, relative weight, topographic location). In microscopic aspects, the spleen in humans and other mammals is composed of stroma, in addition to parenchyma, constituted in turn by white and red pulp. In particular, there are differences between rat, human, cat, dog and pig spleens in shapes, sizes and microscopic aspects related to microcirculation and immunity. While there are similarities in pathological processes and responses to pharmacological and clinical treatments. For the above mentioned, it is concluded that the albino rat constitutes a good biological model, specifically in microscopic anatomical aspects of the spleen of immunological type. While the pig spleen is comparatively better in macroscopic anatomical studies of surgical type, both are extrapolable especially to human medicine.

The Comparative Anatomy of the Upper Digestive System in 26 Species of Zoophagous-Polyphagous Palearctic Birds / Anatomía Comparada del Sistema Digestivo Superior en 26 Especies de Aves Paleárticas Zoófagas-Polífagas

SUMMARY: Birds are the most diversified organisms on Earth, with species covering various niches in each major biome, being essential to understand the modern ecosystem. This study concentrates on the diversification of the anatomical structure of the upper digestive tract for 26 species of zoophage-polyphagous birds and the anatomical differences in the digestive system to reveal aspects related to their evolution and diversification. The trophic spectrum of the selected birds includes several categories of food, or, as in the case of strictly carnivorous birds, to a single food category. After performing the dissections, the digestive tract was separated from the carcass and each digestive segment was measured and analysed. In this study, it was demonstrated that the birds' feeding behaviour influence the macroscopic particularities of the digestive system, more visible in the cranial portion (oropharyngeal cavity, esophagus, proventriculus and gizzard), with little descriptive information in the literature. The tongue is poorly developed and immobile in piscivorous birds, while the tongue of insectivorous birds is long and moves considerably away from the tip of the bill. The esophagus was stretchable and presents longitudinal folds on its entire surface in piscivorous species and not extensible in insectivorous birds.

Las aves son los organismos más diversificados de la Tierra, con especies que cubren varios nichos en cada bioma principal, siendo esenciales para comprender el ecosistema moderno. Este estudio se concentra en la diversificación de la estructura anatómica del tracto digestivo superior para 26 especies de aves zoófago-polífagas y las diferencias anatómicas en el sistema digestivo para revelar aspectos relacionados con su evolución y diversificación. El espectro trófico de las aves seleccionadas incluye varias categorías de alimentos o, como en el caso de las aves estrictamente carnívoras, una sola categoría de alimentos. Después de realizar las disecciones, se separó el tracto digestivo de la canal y se midió y analizó cada segmento digestivo. En este estudio se demostró que el comportamiento alimentario de las aves influye en las particularidades macroscópicas del sistema digestivo, más visibles en la porción craneal (cavidad orofaríngea, esófago, proventrículo y molleja), con poca información descriptiva en la literatura. En las aves piscívoras, la lengua está poco desarrollada e inmóvil, mientras que la lengua de las aves insectívoras es larga y se aleja considerablemente de la punta del pico. El esófago era estirable y presentaba pliegues longitudinales en toda su superficie en especies piscívoras y no extensible en aves insectívoras.

The roar of Rancho La Brea? Comparative anatomy of modern and fossil felid hyoid bones.

Animal vocalization is broadly recognized as ecologically and evolutionarily important. In mammals, hyoid elements may influence vocalization repertoires because the hyoid apparatus anchors vocal tissues, and its morphology can be associated with variation in surrounding soft-tissue vocal anatomy. Thus, fossil hyoid morphology has the potential to shed light on vocalizations in extinct taxa. Yet, we know little about the hyoid morphology of extinct species because hyoid elements are rare in the fossil record. An exception is found in the Rancho La Brea tar pits in Los Angeles, California, where enough hyoids have been preserved to allow for quantitative analyses. The La Brea Tar Pits and Museum houses one of the largest and most diverse collections of carnivore fossils, including hyoid elements from the extinct felids Smilodon fatalis and Panthera atrox. Here, we found that extant members of Felinae (purring cats) and Panthera (roaring cats) showed characteristic differences in hyoid size and shape that suggest possible functional relationships with vocalization. The two extinct taxa had larger and more robust hyoids than extant felids, potentially reflecting the ability to produce lower frequency vocalizations as well as more substantial muscles associated with swallowing and respiration. Based on the shape of the hyoid elements, Panthera atrox resembled roaring cats, while Smilodon fatalis was quite variable and, contrary to suggestions from previous research, more similar overall to purring felids. Thus P. atrox may have roared and S. fatalis may have produced vocalizations similar to extant purring cats but at a lower frequency. Due to the confounding of vocalization repertoire and phylogenetic history in extant Felidae, we cannot distinguish between morphological signals related to vocalization behavior and those related to shared evolutionary history unrelated to vocalization.

Soft tissues influence nasal airflow in diapsids: Implications for dinosaurs.

The nasal passage performs multiple functions in amniotes, including olfaction and thermoregulation. These functions would have been present in extinct animals as well. However, fossils preserve only low-resolution versions of the nasal passage due to loss of soft-tissue structures after death. To test the effects of these lower resolution models on interpretations of nasal physiology, we performed a broadly comparative analysis of the nasal passages in extant diapsid representatives, e.g., alligator, turkey, ostrich, iguana, and a monitor lizard. Using computational fluid dynamics, we simulated airflow through 3D reconstructed models of the different nasal passages and compared these soft-tissue-bounded results to similar analyses of the same airways under the lower-resolution limits imposed by fossilization. Airflow patterns in these bony-bounded airways were more homogeneous and slower flowing than those of their soft-tissue counterparts. These data indicate that bony-bounded airway reconstructions of extinct animal nasal passages are far too conservative and place overly restrictive physiological limitations on extinct species. In spite of the diverse array of nasal passage shapes, distinct similarities in airflow were observed, including consistent areas of nasal passage constriction such as the junction of the olfactory region and main airway. These nasal constrictions can reasonably be inferred to have been present in extinct taxa such as dinosaurs.

Comparative anatomy of the felid brachial plexus reflects differing hunting strategies between Pantherinae (snow leopard, Panthera uncia) and Felinae (domestic cat, Felis catus).

The brachial plexus, a network of ventral rami providing somatic sensory and motor innervation to the forelimb, is of particular importance in felids. Large-bodied pantherines require powerful rotatory and joint stabilizing forelimb muscles to maintain secure holds on large prey, while smaller-bodied felines are small prey specialists reliant on manual dexterity. Brachial plexus dissections of two snow leopards (Panthera uncia) and two domestic cats (Felis catus) revealed that generally the morphology of the brachial plexus is quite conserved. However, differences in the nerves supplying the shoulder and antebrachium may reflect differing prey capture strategies between the subfamilies. The brachial plexus of both species derives from ventral rami of C6-T1. In P. uncia, an extensive musculus (m.) subscapularis with multiple pennations is innervated by a larger number of nn. subscapulares, deriving from more spinal cord levels than in F. catus. C6 continues to become n. suprascapularis in both taxa; however, in F. catus, it also gives branches that join with C7, while in P. uncia, it is dedicated to musculi (mm.) supraspinatus, infraspinatus, and a small branch to cervical musculature. In F. catus, nervus (n.) medianus receives direct contributions from more ventral rami than P. uncia, possibly reflecting a greater reliance on manual dexterity in prey capture in the former. In addition to primary innervation by n. thoracodorsalis, m. latissimus dorsi is also innervated by n. thoracicus lateralis near the axilla in both taxa, suggesting that it may belong to a complex of proximal forelimb musculature along with mm. pectoralis profundus and cutaneus trunci.

Bridging mouse and human anatomies; a knowledge-based approach to comparative anatomy for disease model phenotyping.

The laboratory mouse is the foremost mammalian model used for studying human diseases and is closely anatomically related to humans. Whilst knowledge about human anatomy has been collected throughout the history of mankind, the first comprehensive study of the mouse anatomy was published less than 60 years ago. This has been followed by the more recent publication of several books and resources on mouse anatomy. Nevertheless, to date, our understanding and knowledge of mouse anatomy is far from being at the same level as that of humans. In addition, the alignment between current mouse and human anatomy nomenclatures is far from being as developed as those existing between other species, such as domestic animals and humans. To close this gap, more in depth mouse anatomical research is needed and it will be necessary to extent and refine the current vocabulary of mouse anatomical terms.

Comparative anatomy of the mitral valve in four species (human, ovine, porcine and canine): A pre-clinical perspective.

This study aimed to provide comparative anatomical data on the mitral valve and to substantiate the choice between large species for pre-clinical testing of cardiac devices. Different anatomical parameters of the anterior and posterior leaflets, chordae and papillary muscles were measured to characterize the anatomy of the mitral valve in 10 individuals for each four species. Ratios were calculated and used to circumvent the interspecies variations of body and heart size and weight. The results underline many relevant anatomical similarities and differences between man and the three animal species. We confirm that the porcine species is a better model based on anatomical measurements. But many parameters should be considered depending on the shape, size and purpose of the device. The mitral and aortic valve are closer than in man leading to potential damage of the aortic valve by a mitral device. The ovine mitral annulus is more flattened and would sustain more mechanical forces on a round-shaped stent. The anterior and posterior leaflets have comparable height in the animal species leading to more space for implantation. The porcine valve has more chordae allowing less space around the valve for a transcatheter stent. Our observations introduce new comparative data in the perspective of the choice of a large animal model for pre-clinical testing of mitral devices. They are very helpful for all cardiologists, surgeons or engineers who need to understand the reasons for success or failure of a device and to have key elements of discussion.

The very rare Japanese endemic diving beetle Japanolaccophilus niponensis (Kamiya, 1939), (Coleoptera: Dytiscidae, Laccophilinae): larval morphology and phylogenetic comparison with other known Laccophilini.

The three larval instars of Japanolaccophilus niponensis (Kamiya, 1939) (Coleoptera: Adephaga, Laccophilinae) are described for the first time according to the now genevralized larval descriptive format of Dytiscidae (Coleoptera: Adephaga), which incorporates detailed chaetotaxic and morphometric analyses. A parsimony analysis based on larval characteristics of 14 Laccophilini species in seven genera was conducted using the program TNT. One of the main results is that Japanolaccophilus Satô, 1972, which so far was treated as being related to Neptosternus Sharp, 1882 now stands out as sister to Laccophilus Leach, 1815, and Philodytes J. Balfour-Browne, 1938 with strong support. Additionally, Laccomimus Toledo & Michat, 2015, and Africophilus Guignot, 1948 are resolved as monophyletic and sister to a clade which itself is subdivided into two well supported clades: Neptosternus + Australphilus Watts, 1978, and Japanolaccophilus + (Laccophilus, Philodytes). Philodytes is here newly accepted as junior synonym of Laccophilus.

Evolutionary traces of miniaturization in a giant-Comparative anatomy of brain and brain nerves in Bathochordaeus stygius (Tunicata, Appendicularia).

Appendicularia comprises 70 marine, invertebrate, chordate species. Appendicularians play important ecological and evolutionary roles, yet their morphological disparity remains understudied. Most appendicularians are small, develop rapidly, and with a stereotyped cell lineage, leading to the hypothesis that Appendicularia derived progenetically from an ascidian-like ancestor. Here, we describe the detailed anatomy of the central nervous system of Bathochordaeus stygius, a giant appendicularian from the mesopelagic. We show that the brain consists of a forebrain with on average smaller and more uniform cells and a hindbrain, in which cell shapes and sizes vary to a greater extent. Cell count for the brain was 102. We demonstrate the presence of three paired brain nerves. Brain nerve 1 traces into the epidermis of the upper lip region and consists of several fibers with some supportive bulb cells in its course. Brain nerve 2 innervates oral sensory organs and brain nerve 3 innervates the ciliary ring of the gill slits and lateral epidermis. Brain nerve 3 is asymmetric, with the right nerve consisting of two neurites originating posterior to the left one that contains three neurites. Similarities and differences to the anatomy of the brain of the model species Oikopleura dioica are discussed. We interpret the small number of cells in the brain of B. stygius as an evolutionary trace of miniaturization and conclude that giant appendicularians evolved from a small, progenetic ancestor that secondarily increased in size within Appendicularia.