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Integrative and Comparative Biology Sep 2021Tails are versatile structures with diverse forms and functions across vertebrates. They are involved in almost all behaviors critical to survival including locomotion,...
Tails are versatile structures with diverse forms and functions across vertebrates. They are involved in almost all behaviors critical to survival including locomotion, feeding, and predator avoidance. Although the tail's role in locomotion and stability has been widely studied, its role in prey capture is relatively unknown. Lizards are an ideal system to examine the tail's impact on prey capture as most are capable of autotomizing, or dropping, their tail in response to predation and intraspecific competition. Tail autotomy can lower reproduction, decrease locomotor performance, impart instability during jumping, and decrease social status. Desert banded geckos (Coleonyx variegatus) frequently capture evasive prey in nature and appear to use their tail during strikes. However, it is unclear if these tail movements are important for the strike itself, or if they simply draw attention to that part of the body. We used high-speed 3D videography to quantify prey capture performance and kinematics of C. variegatus striking at crickets before and after total caudal autotomy. Trials were conducted within 2 h of autotomy and then repeatedly over a 2-week period. Overall, prey capture success was unaffected by caudal autotomy. However, maximum strike velocity decreased significantly after autotomy, highlighting the importance of the tail during prey capture. Strike kinematics were altered after autotomy in several ways, including geckos adopting a more sprawled posture. Maximum pectoral girdle and mid-back height were significantly lower during post-autotomy strikes, whereas maximum pelvic girdle height was unaffected. However, individual variation was considerable. This downward pitching of the body after tail loss suggests that the tail is necessary for counterbalancing the anterior portion of the body and resisting the rotational inertia incurred after pushing off with the hindlimbs. Utilizing autotomy to test tail function in prey capture can provide valuable insight into how the tail is used in terrestrial predation across a wide variety of species and ecological niches.
Topics: Animals; Biomechanical Phenomena; Hindlimb; Lizards; Locomotion; Predatory Behavior; Tail
PubMed: 33988701
DOI: 10.1093/icb/icab076 -
Journal of Morphology Aug 2023Mudskippers are a group of amphibious fishes in the family Oxudercidae, whose species inhabit a range of habitats from mostly aquatic to mostly terrestrial. Most of our...
Mudskippers are a group of amphibious fishes in the family Oxudercidae, whose species inhabit a range of habitats from mostly aquatic to mostly terrestrial. Most of our understanding about habitat preference comes from natural history observations, particularly where they are collected (i.e., low intertidal vs. high intertidal regions). Mudskippers have undergone several morphological changes to accommodate a terrestrial life, including major changes to the pectoral and pelvic girdles. These changes result in a novel crutching gait, which mudskippers use to move over land. Though the appendicular morphology and crutching gait of mudskippers have been described in some species, few studies have compared skeletal structures across the family. In our study, we use microcomputed tomography (µCT) scans to compare the skeletal anatomy of 16 species of aquatic and terrestrial mudskippers. Linear discriminant analysis is used to analyze measurements obtained through geometric morphometrics (landmarks). We found bone structures of the pectoral region in the terrestrial group were significantly longer and wider than those in the aquatic group. Furthermore, a significant difference in anatomy is shown between terrestrial and aquatic genera with both axial and appendicular elements contributing to the separation between groups. This work describes the differences in skeletal morphology associated with terrestriality in mudskippers and provides valuable insights into specific anatomical characteristics contributing to their adaptation to novel environments.
Topics: Animals; Animal Fins; X-Ray Microtomography; Ecosystem; Fishes
PubMed: 37458082
DOI: 10.1002/jmor.21612 -
Journal of Morphology Sep 2017Most suction-feeding, aquatic vertebrates create suction by rapidly enlarging the oral cavity and pharynx. Forceful enlargement of the pharynx is powered by longitudinal...
Most suction-feeding, aquatic vertebrates create suction by rapidly enlarging the oral cavity and pharynx. Forceful enlargement of the pharynx is powered by longitudinal muscles that retract skeletal elements of the hyoid, more caudal branchial arches, and, in many fish, the pectoral girdle. This arrangement was thought to characterize all suction-feeding vertebrates. However, it does not exist in the permanently aquatic, tongueless Pipa pipa, an Amazonian frog that can catch fish. Correlating high-speed (250 and 500 fps) video records with anatomical analysis and functional tests shows that fundamental features of tetrapod body design are altered to allow P. pipa to suction-feed. In P. pipa, the hyoid apparatus is not connected to the skull and is enclosed by the pectoral girdle. The major retractor of the hyoid apparatus arises not from the pectoral girdle but from the femur, which lies largely within the soft tissue boundaries of the trunk. Retraction of the hyoid is coupled with expansion of the anterior trunk, which occurs when the hypertrophied ventral pectoral elements are depressed and the urostyle and sacral vertebra are protracted and slide forward on the pelvic girdle, thereby elongating the entire trunk. We suggest that a single, robust pair of muscles adduct the cleithra to depress the ventral pectoral elements with force, while modified tail muscles slide the axial skeleton cranially on the pelvic girdle. Combined hyoid retraction, axial protraction, and pectoral depression expand the buccopharyngeal cavity to a volume potentially equal to that of the entire resting body of the frog. Pipa may be the only tetrapod vertebrate clade that enlarges its entire trunk during suction-feeding.
Topics: Animals; Anura; Biomechanical Phenomena; Feeding Behavior; Hyoid Bone; Jaw; Muscles; Predatory Behavior; Suction
PubMed: 28547886
DOI: 10.1002/jmor.20707 -
Molecular Phylogenetics and Evolution Apr 2018The Odontobutidae is a group of freshwater sleepers endemic to East and Southeast Asia. The composition of the Odontobutidae is controversial and the systematics...
The Odontobutidae is a group of freshwater sleepers endemic to East and Southeast Asia. The composition of the Odontobutidae is controversial and the systematics position of some species (e.g. Philypnus chalmersi) remains unknown. Phylogenetic relationship among the odontobutids has never been really tested due to the lack of informative morphological characters, and that molecular data have not been collected in many species. Here, we sampled 41 specimens, representing all known genera of the Odontobutidae except the Laotian genus Terateleotris, in addition to a disputable odontobutid species, Philypnus chalmersi and 14 outgroups (six families). We collected sequence data of 4434 single-copy nuclear coding loci using gene capture and Illumina sequencing. A robust phylogeny of the odontobutids and outgroups was built, confirming that the Odontobutidae is monophyletic and sister to the Rhyacichthyidae. We verified that Neodontobutis, Sineleotris and Philypnus chalmersi are members of the Odontobutidae based on the resulting phylogeny as well as patterns of pectoral girdle examined by X-ray microtomography. We proposed a new genus Microdous for Philypnus chalmersi based on the new morphological and molecular evidences. The family of the Odontobutidae can be divided into two clades: Microdous (=Philypnus) sister to a group consisting of Micropercops and Sineleotris, and Odontobutis sister to a group unifying Perccottus and Neodontobutis. Divergence time among the odontobutids was estimated based on 100 most clock-like loci and three fossil calibration points using BEAST. Ancestral range of the family was reconstructed using Reconstruct Ancestral States in Phylogenies (RASP) and BioGeoBEARS. The results suggest that the common ancestor of the odontobutids originated around 30.8 Ma (20.7-42.0 Ma, 95% HPDs) in South China. Orogeny, climatic change and river capture might account for diversification and current distribution of the odontobutids.
Topics: Animals; Bone and Bones; Calibration; China; Fossils; Fresh Water; Likelihood Functions; Perciformes; Phylogeny; Phylogeography; Sequence Analysis, DNA; Species Specificity; Time Factors
PubMed: 29288798
DOI: 10.1016/j.ympev.2017.12.026 -
Anatomical Record (Hoboken, N.J. : 2007) Jun 2023This article presents a detailed comparative analysis of the bone microstructure of three extant species of South American turtles. The main histological characteristics...
Comparative postcranial osteohistology and bone histovariability of aquatic and terrestrial turtles: the case of the South American Phrynops hilarii, Hydromedusa tectifera (Pleurodira, Chelidae), and Chelonoidis chilensis (Cryptodira, Testudinidae).
This article presents a detailed comparative analysis of the bone microstructure of three extant species of South American turtles. The main histological characteristics of postcranial bones are identified, as well as the intraskeletal, ontogenetic and interspecific variation between aquatic and terrestrial species. For this purpose, thin sections of postcranial bones (seventh cervical vertebra, coracoid, scapula, humerus, radius, ulna, ischium, ilium, pubis, femur, tibia, and fibula) of juvenile and adult specimens of aquatic (Phrynops hilarii and Hydromedusa tectifera) and terrestrial (Chelonoidis chilensis) turtles were analyzed. Bone histology revealed an intraskeletal variation of the microanatomical and microstructural organization in these turtles. The cortical bone is composed of poorly vascularized lamellar and parallel-fibered bone tissue interrupted with lines of arrested growth (LAGs), reflecting a cyclical slow growth rate throughout these turtles' life. Although in the adult specimens a growth rate decrease was observed, none of them have reached somatic maturity. The juvenile and the adult of Chelonoidis chilensis, unlike the aquatic species studied, presented a higher vascularization in their bones, which could imply a faster growth rate in this land specie. The number of LAGs was higher in the stylopodial and zeugopodial bones, which would make these elements suitable for approximate age estimations. Pectoral and pelvic girdle bones also exhibited a good record of LAGs. The information here obtained on extant species represents a powerful tool for the interpretation of paleobiological traits present in closely related fossil forms.
Topics: Animals; Turtles; Cortical Bone; Tibia; Humerus; South America
PubMed: 36469456
DOI: 10.1002/ar.25131 -
Pediatric Radiology Jul 2020Skeletal fractures, a common injury in physically abused children, often go undetected and untreated for significant lengths of time and are sometimes incidentally...
Skeletal fractures, a common injury in physically abused children, often go undetected and untreated for significant lengths of time and are sometimes incidentally discovered radiographically. Our objective was to review current literature for scientific studies of pediatric fracture healing with associated timelines. We conducted a search of Embase, EBSCOhost, MEDLINE (PubMed), and Web of Science for literature published from the earliest available up to August 2018. We evaluated the included articles for quality, with consideration for use in clinical and forensic settings. Of a total of 313 full-text articles evaluated, 10 met study inclusion criteria. The patient age range among studies was 0-17 years, with children younger than 1 year included in the majority of studies. The fracture locations included in studies were primarily fractures of the upper limb and pectoral girdle, followed by fractures of the lower limb. The radiographic features of healing varied greatly among the studies. Timelines of common fracture healing variables differed significantly among studies. Scientific, radiographic studies of pediatric fracture healing are limited. Gaps in knowledge regarding fracture healing highlight the need for future research and validation studies. Fracture healing timelines derived from existing timelines should be used with caution.
Topics: Child; Child Abuse; Forensic Medicine; Fracture Healing; Fractures, Bone; Humans; Incidental Findings; Time Factors
PubMed: 32157365
DOI: 10.1007/s00247-020-04648-7 -
Royal Society Open Science Nov 2022The evolution of morphological diversity has held a long-standing fascination among scientists. In particular, do bodies evolve as single, integrated units or do...
The evolution of morphological diversity has held a long-standing fascination among scientists. In particular, do bodies evolve as single, integrated units or do different body parts evolve semi-independently (modules)? Suckermouth armoured catfishes (Loricariidae) have a morphology that lends nicely to evolutionary modularity and integration studies. In addition to a ventrally facing oral jaw that directly contacts surfaces, the neurocranium and pectoral girdle are fused, which limits movement of the anterior part of the body. Functional constraints suggest it is likely the head and post-cranial body act as separate modules that can evolve independently. If true, one would expect to see a two- or three-module system where the head and post-cranial body are morphologically distinct. To test this hypothesis, we quantified shape using geometric morphometric analysis and assessed the degree of modularity across functionally important regions. We found the armoured catfish body is highly modularized, with varying degrees of integration between each module. Within subfamilies, there are different patterns of evolutionary modularity and integration, suggesting that the various patterns may have driven diversification along a single trajectory in each subfamily. This study suggests the evolution of armoured catfish diversification is complex, with morphological evolution influenced by interactions within and between modules.
PubMed: 36425524
DOI: 10.1098/rsos.220713 -
Journal of Anatomy Dec 2022Stereospondyli are a clade of large aquatic temnospondyls known to have evolved a large dermal pectoral girdle. Among the Stereospondyli, metoposaurids in particular...
Stereospondyli are a clade of large aquatic temnospondyls known to have evolved a large dermal pectoral girdle. Among the Stereospondyli, metoposaurids in particular possess large interclavicles and clavicles relative to the rest of the postcranial skeleton. Because of the large size of these dermal bones, it was first proposed that they served as ballast during hydrostatic buoyancy control which assisted metoposaurids to live a bottom-dwelling mode of life. However, a large bone need not necessarily be heavy, for which determining the bone compactness becomes crucial for understanding any such adaptation in these dermal bones. Previous studies on the evolution of bone adaptations to aquatic lifestyles such as osteosclerosis, pachyostosis, osteoporotic-like pattern and pachyosteosclerosis have been observed in the long bones of secondarily aquatic amniotes. However, there are no known studies on the analysis of bone compactness in the dermal pectoral girdle of non-amniote taxa including Temnospondyli. This study looks at evidence of changes in bone mass adaptations in the dermal bones of the pectoral girdle of two stereospondyls occurring in the Late Triassic Krasiejόw locality (Southwestern Poland), namely: Metoposaurus krasiejowensis and Cyclotosaurus intermedius. However, because of lack of research on bone compactness of temnospondyls in general, there is no existent frame of reference to infer bone mass increase (BMI) in the M. krasiejowensis samples, and thus the bone compactness results of this taxon are compared with that of the samples of C. intermedius. Results of this study indicate that the interclavicles of M. krasiejowensis partially evolved BMI-like condition rendering these bones to be heavy enough to get selected as ballast during hydrostatic buoyancy control. Additionally, M. krasiejowensis shared its habitat with C. intermedius, however, the dermal pectoral girdle sample of the latter taxon does not display signs of BMI-like condition. Furthermore, the absence of variation in hydrostatic buoyancy control in the ontogenetic series of interclavicles of M. krasiejowensis could imply lack of ontogenetic niche shift along the water column.
Topics: Animals; Amphibians; Bone and Bones; Bone Density; Adaptation, Physiological; Clavicle; Biological Evolution; Fossils
PubMed: 36165276
DOI: 10.1111/joa.13755 -
Anatomical Record (Hoboken, N.J. : 2007) Sep 2022We present a detailed anatomy of the pectoral girdles, pelvic girdles, and hindlimbs of adult and juvenile specimens of Pseudopus apodus (Pallas, 1775). We compared the...
We present a detailed anatomy of the pectoral girdles, pelvic girdles, and hindlimbs of adult and juvenile specimens of Pseudopus apodus (Pallas, 1775). We compared the individual bones of the appendicular skeleton of P. apodus with those of Anguis fragilis and species of Ophisaurus living in North America, North Africa, and Southeast Asia. We found no anatomical features in P. apodus in common with the species of Ophisaurus living in only North America, North Africa, and Southeast Asia. Additionally, we present the prehatching ontogeny of the pelvic girdle of P. apodus and A. fragilis and the prehatching ontogeny of the hindlimb of P. apodus. In the ontogeny of the pelvic girdle of P. apodus, it is possible to distinguish the ossification centers of ilium, ischium, and pubis. In contrast, in the ontogeny of A. fragilis, no ossification centers of ilium, ischium, and pubis are present, and no hindlimb element was detected. In Stage 1 of ontogeny in Pseudopus, the femur and tibia are present; in Stage 2, the nodule representing the fibula appears; and in Stage 3, in addition to the femur, tibia, and fibula, four tarsal elements are present. This anatomical condition corresponds to the anatomical composition of the hindlimb of the adult O. koellikeri. In Stage 4, the involution of all tarsal elements and fibula begins, and in the last two prehatching stages, only femur and tibia remain; this condition is present not only in the adults of Pseudopus, but also in those of several other species of Ophisaurus.
Topics: Anatomy, Comparative; Animals; Hindlimb; Ischium; Lizards; Lower Extremity
PubMed: 34881500
DOI: 10.1002/ar.24851 -
PeerJ 2024Important transformations of the pectoral girdle are related to the appearance of flight capabilities in the Dinosauria. Previous studies on this topic focused mainly on...
Important transformations of the pectoral girdle are related to the appearance of flight capabilities in the Dinosauria. Previous studies on this topic focused mainly on paravians yet recent data suggests flight evolved in dinosaurs several times, including at least once among non-avialan paravians. Thus, to fully explore the evolution of flight-related avian shoulder girdle characteristics, it is necessary to compare morphology more broadly. Here, we present information from pennaraptoran specimens preserving pectoral girdle elements, including all purportedly volant taxa, and extensively compare aspects of the shoulder joint. The results show that many pectoral girdle modifications appear during the evolution from basal pennaraptorans to paravians, including changes in the orientation of the coracoid body and the location of the articulation between the furcula and scapula. These modifications suggest a change in forelimb range of motion preceded the origin of flight in paravians. During the evolution of early avialans, additional flight adaptive transformations occur, such as the separation of the scapula and coracoid and reduction of the articular surface between these two bones, reduction in the angle between these two elements, and elongation of the coracoid. The diversity of coracoid morphologies and types of articulations joining the scapula-coracoid suggest that each early avialan lineage evolved these features in parallel as they independently evolved more refined flight capabilities. In early ornithothoracines, the orientation of the glenoid fossa and location of the acrocoracoid approaches the condition in extant birds, suggesting a greater range of motion in the flight stroke, which may represent the acquisition of improved powered flight capabilities, such as ground take-off. The formation of a new articulation between the coracoid and furcula in the Ornithuromorpha is the last step in the formation of an osseous triosseal canal, which may indicate the complete acquisition of the modern flight apparatus. These morphological transitions equipped birds with a greater range of motion, increased and more efficient muscular output and while at the same time transmitting the increased pressure being generated by ever more powerful flapping movements in such a way as to protect the organs. The driving factors and functional adaptations of many of these transitional morphologies are as yet unclear although ontogenetic transitions in forelimb function observed in extant birds provide an excellent framework through which we can explore the behavior of Mesozoic pennaraptorans.
Topics: Animals; Shoulder Joint; Upper Extremity; Forelimb; Birds; Dinosaurs; Scapula
PubMed: 38436017
DOI: 10.7717/peerj.16960