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PeerJ 2022Hutt et al., 2001 from the Lower Cretaceous Wessex Formation (part of the Wealden Supergroup) of the Isle of Wight, southern England, is described in detail, compared...
Hutt et al., 2001 from the Lower Cretaceous Wessex Formation (part of the Wealden Supergroup) of the Isle of Wight, southern England, is described in detail, compared with other theropods, and evaluated in a new phylogenetic analysis. is represented by a single individual that would have been c. 4.5 m long; it preserves the anterior part of the skull, a partial forelimb and pectoral girdle, various cervical, dorsal and caudal vertebrae, rib fragments, part of the ilium, and hindlimb elements excluding the femur. Lack of fusion with regard to both neurocentral and sacral sutures indicates subadult status. possesses thickened, fused, pneumatic nasals with deep lateral recesses, elongate, tridactyl forelimbs and a tyrannosaurid-like scapulocoracoid. The short preantorbital ramus of the maxilla and nasals that are approximately seven times longer than they are wide show that was not longirostrine. A posterodorsally inclined ridge on the ilium's lateral surface fails to reach the dorsal margin: a configuration seen elsewhere in . is not arctometatarsalian. Autapomorphies include the presence of curving furrows on the dentary, a block-like humeral entepicondyle, and a distoproximally aligned channel close to the distolateral border of the tibia. Within Tyrannosauroidea, is phylogenetically intermediate between Proceratosauridae and and the clade that includes , Megaraptora, and Tyrannosauridae. We do not find support for a close affinity between and . Our analysis supports the inclusion of Megaraptora within Tyrannosauroidea and thus increases Cretaceous tyrannosauroid diversity and disparity. A proposal that might belong within Megaraptora, however, is based on character states not present in the taxon. Several theropods from the Wessex Formation are based on material that overlaps with the holotype but none can be shown to be synonymous with it.
Topics: Animals; Phylogeny; Fossils; Osteology; Skull; Tibia; Dinosaurs
PubMed: 35821895
DOI: 10.7717/peerj.12727 -
Integrative and Comparative Biology Oct 2022Research on the water-to-land transition tends to focus on the locomotor changes necessary for terrestriality. However, the evolution from water breathing to air...
Research on the water-to-land transition tends to focus on the locomotor changes necessary for terrestriality. However, the evolution from water breathing to air breathing was also a necessary precursor to the invasion of land. Air is approximately 1000 times less dense and 50 times less viscous, and contains hundreds of times more oxygen than water. However, unlike the transition to terrestrial locomotion, breathing air does not require body weight support, so the evolution of air breathing may have necessitated smaller changes to morphology and function. We used X-ray reconstruction of moving morphology to compare the cranial kinematics of aquatic buccal pumping, such as that seen in suction feeding, with the aerial buccal pumping required for lung ventilation in the West African lungfish (Protopterus annectens). During buccal pumping behaviors, the cranial bones and associated soft tissues act as valves and pumps, and the sequence of their motions controls the pattern of fluid flow. Both behaviors are characterized by an anterior-to-posterior wave of expansion and an anterior-to-posterior wave of compression. We found that the pectoral girdle and cranial rib rotate consistently during air breathing and suction feeding, and that the muscle between them shortens during buccal expansion. Overall, we conclude that the major cranial bones maintain the same basic functions (i.e., acting as valves or pumps, or transmitting power) across aquatic and aerial buccal pumping. The cranial morphology that enables aquatic buccal pumping is well suited to perform air breathing and accommodates the physical differences between air and water.
Topics: Animals; Biomechanical Phenomena; Suction; Fishes; Respiration; Water
PubMed: 35798019
DOI: 10.1093/icb/icac109 -
Anatomy & Cell Biology Jun 2022Anatomical variation is defined as normal flexibility in the topography and morphology of body structures. Such variations are not uncommon in muscles, particularly in...
Anatomical variation is defined as normal flexibility in the topography and morphology of body structures. Such variations are not uncommon in muscles, particularly in the upper limb. Subclavius muscle (SM) has a proximal attachment to the first costochondral junction and the muscle fibers are then directed upwards and laterally to get attached distally to the subclavian groove of the clavicle. Having similar attachments as the subclavius, the costocoracoid ligament (CCL) is the thickening of the proximal part of clavipectoral fascia extending up to the coracoid process. Both SM and CCL help in the maintenance of smooth movements of the pectoral girdle and both may not always be present. Absent SM may be due to anomalous development from the muscle matrix that also forms the inferior belly of the omohyoid apart from the SMs. This anatomical variation may be associated with thickened CCLs and can be correlated to the smooth functioning of the pectoral girdle.
PubMed: 35773222
DOI: 10.5115/acb.21.246 -
Anatomical Record (Hoboken, N.J. : 2007) Oct 2022The holotype of Junggarsuchus sloani, from the Shishugou Formation (early Late Jurassic) of Xinjiang, China, consists of a nearly complete skull and the anterior half of...
The holotype of Junggarsuchus sloani, from the Shishugou Formation (early Late Jurassic) of Xinjiang, China, consists of a nearly complete skull and the anterior half of an articulated skeleton, including the pectoral girdles, nearly complete forelimbs, vertebral column, and ribs. Here, we describe its anatomy and compare it to other early diverging crocodylomorphs, based in part on CT scans of its skull and that of Dibothrosuchus elaphros from the Early Jurassic of China. Junggarsuchus shares many features with a cursorial assemblage of crocodylomorphs, informally known as "sphenosuchians," whose relationships are poorly understood. However, it also displays several derived crocodyliform features that are not found among most "sphenosuchians." Our phylogenetic analysis corroborates the hypothesis that Junggarsuchus is closer to Crocodyliformes, including living crocodylians, than are Dibothrosuchus and Sphenosuchus, but not as close to crocodyliforms as Almadasuchus and Macelognathus, and that the "Sphenosuchia" are a paraphyletic assemblage. D. elaphros and Sphenosuchus acutus are hypothesized to be more closely related to Crocodyliformes than are the remaining non-crocodyliform crocodylomorphs, which form several smaller groups but are largely unresolved.
Topics: Animals; Fossils; Head; Phylogeny; Skull; Tomography, X-Ray Computed
PubMed: 35699105
DOI: 10.1002/ar.24949 -
Journal of Morphology Aug 2022The Greater Rhea (Rhea americana, Rheidae) is a flightless paleognath with a wide geographical distribution in South America. The morphology of its shoulder girdle and...
The Greater Rhea (Rhea americana, Rheidae) is a flightless paleognath with a wide geographical distribution in South America. The morphology of its shoulder girdle and wings are different from those of flying birds and some characteristics are similar to basal birds and paravian theropods. We present a detailed osteological, myological, and functional study of the shoulder and the wing of the Greater Rhea. Particular features of the anatomy of the pectoral girdle and wing of Rhea include the lack of triosseal canal, reduced origin area of the mm. pectoralis p. thoracica and supracoracoideus and the lack of a propatagium. The wing muscle mass is markedly reduced, reaching only 0.89% of total body mass (BM). Forelimb muscles mass values are low compared to those of flying birds and are congruent with the non-use of wings for active locomotion movements. R. americana does not flap the wings dorso-ventral as typical for flying birds, but predominantly in cranio-caudal direction, following a craniolateral to caudomedial abduction-adduction arc. When the wings are fully abducted, they are inverted L-shaped, with the inner surface caudally faced, and when the wings are folded against the body, they do not perform the complete automatic wing folding nor the circumduction of the manus, a movement performed by extant volant birds. This study complements our knowledge of the axial musculature of the flightless paleognaths and highlights the use of the Greater Rhea as a model, which may help understand the evolution of Palaeognathae, as well as the origin of flapping flight among paravian theropods.
Topics: Animals; Flight, Animal; Osteology; Rheiformes; Struthioniformes; Wings, Animal
PubMed: 35673834
DOI: 10.1002/jmor.21486 -
The Journal of Chiropractic Education Oct 2022The aim of this study is to conduct a pilot survey to determine core anatomy content for chiropractic curriculum based on the perception of chiropractors and anatomy...
OBJECTIVE
The aim of this study is to conduct a pilot survey to determine core anatomy content for chiropractic curriculum based on the perception of chiropractors and anatomy educators involved in teaching in an Australian chiropractic program.
METHODS
A survey of anatomical structures previously used in a medical survey, with similar criteria for synthesizing responses, was used and classified according to whether the respondents rated an item as essential, important, acceptable, or not required in a chiropractic program. The item was scored as core if ≥60% of respondents rated it essential, recommended if 30%-59% rated it essential, not recommended if 20%-29% rated it essential, or not core if <20% rated it essential.
RESULTS
The respondents rated 81.6% of all musculoskeletal concepts as core and 18.4% as recommended, 88.8% of the vertebral column items as core, and 11.2% of the items as recommended, 69.4% upper limb and pectoral girdle items as core, 23.7% of items as recommended, 5.5% as not recommended and 1.3% as not core items for inclusion, 85.3% of all lower limb and pelvic girdle items as core, 14.4% as recommended and 0.3% not recommended.
CONCLUSION
Chiropractors and anatomists involved in teaching in an Australian chiropractic program rated most musculoskeletal items as essential for inclusion in a chiropractic teaching program to ensure adequate preparation for safe practice and to promote alignment with the standards of anatomy education delivered into the clinical professions.
PubMed: 35561322
DOI: 10.7899/JCE-21-18 -
A therian mammal with sprawling kinematics? Gait and 3D forelimb X-ray motion analysis in tamanduas.The Journal of Experimental Biology Jun 2022Therian mammals are known to move their forelimbs in a parasagittal plane, retracting the mobilised scapula during stance phase. Non-cursorial therian mammals often...
Therian mammals are known to move their forelimbs in a parasagittal plane, retracting the mobilised scapula during stance phase. Non-cursorial therian mammals often abduct the elbow out of the shoulder-hip parasagittal plane. This is especially prominent in Tamandua (Xenarthra), which suggests they employ aspects of sprawling (e.g. lizard-like) locomotion. Here, we tested whether tamanduas use sprawling forelimb kinematics, i.e. a largely immobile scapula with pronounced lateral spine bending and long-axis rotation of the humerus. We analysed high-speed videos and used X-ray motion analysis of tamanduas walking and balancing on branches of varying inclinations and provide a quantitative characterization of gaits and forelimb kinematics. Tamanduas displayed lateral sequence/lateral couplets on flat ground and horizontal branches, but increased diagonality on steeper inclines and declines, resulting in lateral sequence/diagonal couplets gaits. This result provides further evidence for high diagonality in arboreal species, probably maximising stability in arboreal environments. Further, the results reveal a mosaic of sprawling and parasagittal kinematic characteristics. The abducted elbow results from a constantly internally rotated scapula about its long axis and a retracted humerus. Scapula retraction contributes considerably to stride length. However, lateral rotation in the pectoral region of the spine (range: 21 deg) is higher than reported for other therian mammals. Instead, it is similar to that of skinks and alligators, indicating an aspect generally associated with sprawling locomotion is characteristic for forelimb kinematics of tamanduas. Our study contributes to a growing body of evidence of highly variable non-cursorial therian mammal locomotor kinematics.
Topics: Animals; Biomechanical Phenomena; Forelimb; Gait; Lizards; Locomotion; Mammals; Vermilingua; X-Rays
PubMed: 35554550
DOI: 10.1242/jeb.243625 -
Zhongguo Shi Yan Xue Ye Xue Za Zhi Apr 2022To explore the characteristics of ADC value changes in DWI of newly diagnosed symptomatic MM patients and its correlation with R-ISS stage.
OBJECTIVE
To explore the characteristics of ADC value changes in DWI of newly diagnosed symptomatic MM patients and its correlation with R-ISS stage.
METHODS
The data of 148 newly diagnosed symptomatic MM patients treated by whole-body DWI scan at The First Affiliated Hospital of Soochow University from June 2016 to June 2019 were selected and retrospectively analyzed and 30 cases of age-matched healthy people were selected as controls. The differences of ADC values between the patients in normal control group, DWI group and DWI group were compared, and the relationship between ADC values and R-ISS stage in MM patients was compared.
RESULTS
The plasma cell percentage of the patients in DWI group was higher than those in DWI group. ADC values of vertebra, sternum, rib, pectoral girdle, pelvic girdle of the patients in DWI group were significantly higher than those in DWI group and normal control group. The ADC values of each part of the patients in DWI group were higher than those in normal control group. ADC values of sternum, rib and pectoral girdle in the patients at R-ISS stage III were higher than those at R-ISS stage I and II, while, there was no statistical difference between R-ISS stage I and II groups. And there was no significant difference in ADC values of other bone parts such as vertebra and pelvic girdle in patients at R-ISS stage Ⅰ-Ⅲ.
CONCLUSION
DWI in MM patients is related to higher tumor invasion. The ADC values of the DWI group are higher than those of the DWI group; the bone ADC values of the DWI patients are still higher than the normal ones. And there is a certain relationship between ADC value and R-ISS stage.
Topics: Bone Diseases; Diffusion Magnetic Resonance Imaging; Humans; Multiple Myeloma; Retrospective Studies; Whole Body Imaging
PubMed: 35395986
DOI: 10.19746/j.cnki.issn.1009-2137.2022.02.029 -
ELife Mar 2022The morphology of the pectoral girdle, the skeletal structure connecting the wing to the body, is a key determinant of flight capability, but in some respects is poorly...
The morphology of the pectoral girdle, the skeletal structure connecting the wing to the body, is a key determinant of flight capability, but in some respects is poorly known among stem birds. Here, the pectoral girdles of the Early Cretaceous birds and are reconstructed for the first time based on computed tomography and three-dimensional visualization, revealing key morphological details that are important for our understanding of early-flight evolution. exhibits a double articulation system (widely present in non-enantiornithine pennaraptoran theropods including crown birds), which involves, alongside the main scapula-coracoid joint, a small subsidiary joint, though variation exists with respect to the shape and size of the main and subsidiary articular contacts in non-enantiornithine pennaraptorans. This double articulation system contrasts with in which a spatially restricted scapula-coracoid joint is formed by a single set of opposing articular surfaces, a feature also present in other members of Enantiornithines, a major clade of stem birds known only from the Cretaceous. The unique single articulation system may reflect correspondingly unique flight behavior in enantiornithine birds, but this hypothesis requires further investigation from a functional perspective. Our renderings indicate that both and had a partially closed triosseal canal (a passage for muscle tendon that plays a key role in raising the wing), and our study suggests that this type of triosseal canal occurred in all known non-euornithine birds except , representing a transitional stage in flight apparatus evolution before the appearance of a fully closed bony triosseal canal as in modern birds. Our study reveals additional lineage-specific variations in pectoral girdle anatomy, as well as significant modification of the pectoral girdle along the line to crown birds. These modifications produced diverse pectoral girdle morphologies among Mesozoic birds, which allowed a commensurate range of capability levels and styles to emerge during the early evolution of flight.
Topics: Animals; Biological Evolution; Birds; Fossils; Phylogeny; Wings, Animal
PubMed: 35356889
DOI: 10.7554/eLife.76086 -
Nature Ecology & Evolution May 2022Among living tetrapods, many lineages have converged on a snake-like body plan, where extreme axial elongation is accompanied by reduction or loss of paired limbs....
Among living tetrapods, many lineages have converged on a snake-like body plan, where extreme axial elongation is accompanied by reduction or loss of paired limbs. However, when and how this adaptive body plan first evolved in amniotes remains poorly understood. Here, we provide insights into this question by reporting on a new taxon of molgophid recumbirostran, Nagini mazonense gen. et sp. nov., from the Francis Creek Shale (309-307 million years ago) of Illinois, United States, that exhibits extreme axial elongation and corresponding limb reduction. The molgophid lacks entirely the forelimb and pectoral girdle, thus representing the earliest occurrence of complete loss of a limb in a taxon recovered phylogenetically within amniotes. This forelimb-first limb reduction is consistent with the pattern of limb reduction that is seen in modern snakes and contrasts with the hindlimb-first reduction process found in many other tetrapod groups. Our findings suggest that a snake-like limb-reduction mechanism may be operating more broadly across the amniote tree.
Topics: Animals; Biological Evolution; Forelimb; Hindlimb; Phylogeny
PubMed: 35347258
DOI: 10.1038/s41559-022-01698-y