Caudofemoral musculature and the evolution of theropod locomotion

Paleobiology ◽  
1990 ◽  
Vol 16 (2) ◽  
pp. 170-186 ◽  
Author(s):  
Stephen M. Gatesy
Keyword(s):  
Knee Flexion ◽  
Hind Limb ◽  
The Body ◽  
Avian Evolution ◽  
Theropod Dinosaurs ◽  
Data Support ◽  
Caudal Vertebrae ◽  
Longus Muscle

Living crocodilians and limbed lepidosaurs have a large caudofemoralis longus muscle passing from tail to femur. Anatomical and electromyographic data support the conclusion that the caudofemoralis is the principal femoral retractor and thus serves as the primary propulsive muscle of the hind limb. Osteological evidence of both origin and insertion indicates that a substantial caudofemoralis longus was present in archosaurs primitively and was retained in the clades Dinosauria and Theropoda. Derived theropods (e.g., ornithomimids, deinonychosaurs, Archaeopteryx and birds) exhibit features that indicate a reduction in caudofemoral musculature, including fewer caudal vertebrae, diminished caudal transverse processes, distal specialization of the tail, and loss of the fourth trochanter. This trend culminates in ornithurine birds, which have greatly reduced tails and either have a minute caudofemoralis longus or lack the muscle entirely.As derived theropod dinosaurs, birds represent the best living model for reconstructing extinct nonavian theropods. Bipedal, digitigrade locomotion on fully erect limbs is an avian feature inherited from theropod ancestors. However, the primitive saurian mechanisms of balancing the body (with a large tail) and retracting the limb (with the caudofemoralis longus) were abandoned in the course of avian evolution. This strongly suggests that details of the orientation (subhorizontal femur) and movement (primarily knee flexion) of the hind limb in extant birds are more properly viewed as derived, uniquely avian conditions, rather than as retentions of an ancestral dinosaurian pattern. Although many characters often associated with extant birds appeared much earlier in theropod evolution, reconstructing the locomotion of all theropods as completely birdlike ignores a wealth of differences that characterize birds.

Macroanatomical Structure of the Lumbosacral Plexus and its Branches in the Indigenous Duck

2018 ◽  
Vol 52 (1-4) ◽  
pp. 1-9 ◽  
Author(s):  
MT Hussan ◽  
MS Islam ◽  
J Alam
Keyword(s):  
Hind Limb ◽  
Femoral Nerve ◽  
Morphological Structure ◽  
Spinal Nerve ◽  
The Body ◽  
Lumbar Plexus ◽  
Lumbosacral Plexus ◽  
Sacral Plexus ◽  
Spinal Nerves ◽  
Femoral Cutaneous Nerve

The present study was carried out to determine the morphological structure and the branches of the lumbosacral plexus in the indigenous duck (Anas platyrhynchos domesticus). Six mature indigenous ducks were used in this study. After administering an anesthetic to the birds, the body cavities were opened. The nerves of the lumbosacral plexus were dissected separately and photographed. The lumbosacral plexus consisted of lumbar and sacral plexus innervated to the hind limb. The lumbar plexus was formed by the union of three roots of spinal nerves that included last two and first sacral spinal nerve. Among three roots, second (middle) root was the highest in diameter and the last root was least in diameter. We noticed five branches of the lumbar plexus which included obturator, cutaneous femoral, saphenus, cranial coxal, and the femoral nerve. The six roots of spinal nerves, which contributed to form three trunks, formed the sacral plexus of duck. The three trunks united medial to the acetabular foramen and formed a compact, cylindrical bundle, the ischiatic nerve. The principal branches of the sacral plexus were the tibial and fibular nerves that together made up the ischiatic nerve. Other branches were the caudal coxal nerve, the caudal femoral cutaneous nerve and the muscular branches. This study was the first work on the lumbosacral plexus of duck and its results may serve as a basis for further investigation on this subject.

First remingtonocetid archaeocete (Mammalia, Cetacea) from the middle Eocene of Egypt with implications for biogeography and locomotion in early cetacean evolution

2015 ◽  
Vol 89 (5) ◽  
pp. 882-893 ◽  
Author(s):  
Ryan M. Bebej ◽  
Iyad S. Zalmout ◽  
Ahmed A. Abed El-Aziz ◽  
Mohammed Sameh M. Antar ◽  
Philip D. Gingerich
Keyword(s):  
Middle Eocene ◽  
Lumbar Vertebrae ◽  
The Body ◽  
Power Stroke ◽  
Tethys Sea ◽  
Vertebral Centra ◽  
Hind Limbs ◽  
Caudal Vertebrae ◽  
Southern Tethys

AbstractRemingtonocetidae are Eocene archaeocetes that represent a unique experiment in cetacean evolution. They possess long narrow skulls, long necks, fused sacra, and robust hind limbs. Previously described remingtonocetids are known from middle Eocene Lutetian strata in Pakistan and India. Here we describe a new remingtonocetid, Rayanistes afer, n. gen. n. sp., recovered from a middle to late Lutetian interval of the Midawara Formation in Egypt. The holotype preserves a sacrum with four vertebral centra; several lumbar and caudal vertebrae; an innominate with a complete ilium, ischium, and acetabulum; and a nearly complete femur. The ilium and ischium of Rayanistes are bladelike, rising sharply from the body of the innominate anterior and posterior to the acetabulum, and the acetabular notch is narrow. These features are diagnostic of Remingtonocetidae, but their development also shows that Rayanistes had a specialized mode of locomotion. The expanded ischium is larger than that of any other archaeocete, supporting musculature for powerful retraction of the hind limbs during swimming. Posteriorly angled neural spines on lumbar vertebrae and other features indicate increased passive flexibility of the lumbus. Rayanistes probably used its enhanced lumbar flexibility to increase the length of the power stroke during pelvic paddling. Recovery of a remingtonocetid in Egypt broadens the distribution of Remingtonocetidae and shows that protocetids were not the only semiaquatic archaeocetes capable of dispersal across the southern Tethys Sea.

Effects of human stature and muscle strength on the standing strategies: A computational biomechanical study

2020 ◽  
Vol 234 (7) ◽  
pp. 674-685
Author(s):  
Mohammed N Ashtiani ◽  
Mahmood-Reza Azghani ◽  
Mohamad Parnianpour ◽  
Kinda Khalaf
Keyword(s):  
Muscle Strength ◽  
Knee Flexion ◽  
Inverse Dynamics ◽  
Biomechanical Model ◽  
Biomechanical Study ◽  
The Body ◽  
Whole Body ◽  
Tall Stature ◽  
Personal Factors ◽  
Hamstring Muscles

It has been hypothesized that the muscular efforts exerted during standing may be altered by changes in personal factors, such as the body stature and muscular strength. The goal of this work was to assess the contribution of leg muscles using a biomechanical model in different physical conditions and various initial postures. An optimized inverse dynamics model was employed to find the maximum muscular effort in 23,040 postures. The simulation results showed that mid-range knee flexion could help the healthy and strong individuals maintain balance, but those with weaker muscle strength required more knee flexion. Individuals of weak muscular constitution as well as those with tall stature are at the highest risk of imbalance/falling. The number of imbalanced postures due to deficits in the calf and hamstring muscles was reduced by 7.5 times by strengthening the whole body musculature. The calf and the hamstring muscles play a key role in balance regardless of stature.

Microelectrode study of dorsal spinocerebellar tract

1962 ◽  
Vol 203 (5) ◽  
pp. 799-802 ◽  
Author(s):  
S. T. Kitai ◽  
F. Morin
Keyword(s):  
Hind Limb ◽  
Sensory Modality ◽  
The Body ◽  
Joint Movement ◽  
Ipsilateral Side ◽  
Sensory Modalities ◽  
Spinocerebellar Tract ◽  
Stimulation Of

The dorsal spinocerebellar tract (DSCT) at C-1, C-2, and the lower medulla level was studied with microelectrodes in lightly anesthetized cats. All responses were obtained from the stimulation of the ipsilateral side of the body. The sensory modalities activating the total of 242 fibers studied were touch (53%), pressure (31%), touch and pressure (2%), and joint movement (14%). Responses to touch were more numerous for the forelimb, while responses to pressure and to joint movement were more numerous for the hind limb. Regardless of modalities the trunk was significantly less represented in the DSCT than the limbs. Tactile and pressure peripheral fields were restricted (i.e., a few hairs of a paw) and large (i.e., more than one segment of a limb). The ratio of restricted to large fields for touch was 7 to 1, and for pressure 5 to 1. Fibers activated by joint movements adjusted their frequency of firing to the degree of displacement and to the rate of the movement. There was no evidence for a separate anatomical segregation of fibers responding to a single sensory modality.

TONIC ADAPTIONS IN DEAFFERENTED LIMBS OF THE CAT

1955 ◽  
Vol 33 (1) ◽  
pp. 139-155
Author(s):  
R. D. Teasdall ◽  
G. W. Stavraky
Keyword(s):  
Hind Limb ◽  
Muscle Tone ◽  
Receptive Fields ◽  
Linear Acceleration ◽  
The Body ◽  
Nerve Roots ◽  
Normal Response ◽  
Postural Reflexes ◽  
Reflex Arc ◽  
Spinal Neurones

In 26 cats postural reflexes and tonic adjustments in the chronically deafferented and intact limbs were studied by means of moving picture and other photographic recordings for a period of four to six months. The positive supporting reactions which were dependent on an intrinsic reflex arc were permanently abolished by the deafferentation. Other segmental reflexes such as the crossed extensor and Philippson's reflex were readily elicited in the deafterented extremity within 24 to 48 hr. after section of the posterior nerve roots, and after longer intervals following the deafferentation these reflexes became greatly exaggerated. They appeared sooner after the operation and became more prominent in the hind limb than in the fore limb.The intersegmental postural reflexes and the scratch reflex were consistently present in the deafferented limbs of chronic animals and the latter reflex became markedly hyperactive within one week after section of the posterior nerve roots. The normal reflex responses to linear acceleration were first depressed by section of the posterior nerve roots, but in one to four weeks after the operation they were readily demonstrable, became exaggerated in the deafferented extremity, and remained so for the rest of the period of observation. Unlike the crossed extensor reflex, these reflexes reappeared first in the fore limb and reached greater prominence in this extremity than they did in the hind limb. A reversal of the tonic labyrinthine and neck reflexes was demonstrated in the deafferented extremities of the chronic animal. This reversal appeared one to two months after section of the posterior nerve roots in the fore limb, and two to three months following deafferentation of the hind limb. When established, the reversal was readily elicited and took place simultaneously with a normal response in the intact extremities on the opposite side of the body. Simultaneously with the changes in postural reflexes, alterations in tone became prominent.The modified and exaggerated postural reflexes and tonic adjustments observed in the deafferented limbs were attributed to a sensitization of the partially denervated spinal neurones to nerve impulses reaching them from various receptive fields other than those originating in the extremity itself. It is felt that the modifications in postural reflexes and subsequent alterations of muscle tone which have been demonstrated in the chronically deafferented extremities of animals may play an important part in the pathogenesis of human sensory ataxia.

Cutaneous Receptors Contribute to Kinesthesia at the Index Finger, Elbow, and Knee

2005 ◽  
Vol 94 (3) ◽  
pp. 1699-1706 ◽  
Author(s):  
D. F. Collins ◽  
K. M. Refshauge ◽  
G. Todd ◽  
S. C. Gandevia
Keyword(s):  
Muscle Spindle ◽  
Knee Flexion ◽  
Index Finger ◽  
Elbow Flexion ◽  
Contralateral Side ◽  
The Body ◽  
Triceps Brachii ◽  
Joint Flexion ◽  
Skin Stretch ◽  
Distal Tendon

The neural mechanisms underlying the sense of joint position and movement remain controversial. While cutaneous receptors are known to contribute to kinesthesia for the fingers, the present experiments test the hypothesis that they contribute at other major joints. Illusory movements were evoked at the interphalangeal (IP) joints of the index finger, the elbow, and the knee by stimulation of populations of cutaneous and muscle spindle receptors, both separately and together. Subjects matched perceived movements with voluntary movements of homologous joints on the contralateral side. Cutaneous receptors were activated by stretch of the skin (using 2 intensities of stretch) and vibration activated muscle spindle receptors. Stimuli were designed to activate receptors that discharge during joint flexion. For the index finger, vibration was applied over the extensor tendons on the dorsum of the hand, to evoke illusory metacarpophalangeal (MCP) joint flexion, and skin stretch was delivered around the IP joints. The strong skin stretch evoked the illusion of flexion of the proximal IP joint in 6/8 subjects (12 ± 5°, mean ± SE). For the group, strong skin stretch delivered during vibration increased the perceived flexion of the proximal IP joint by eight times with a concomitant decrease in perceived flexion of the MCP joint compared with vibration alone ( P < 0.05). For the elbow, vibration was applied over the distal tendon of triceps brachii and skin stretch over the dorsal forearm. When delivered alone, strong skin stretch evoked illusory elbow flexion in 5/10 subjects (9 ± 4°). Simultaneous strong skin stretch and vibration increased the illusory elbow flexion for the group by 1.5 times compared with vibration ( P < 0.05). For the knee, vibration was applied over the patellar tendon and skin stretch over the thigh. Skin stretch alone evoked illusory knee flexion in 3/10 subjects (8 ± 4°) and when delivered during vibration, perceived knee flexion increased for the group by 1.4 times compared with vibration ( P < 0.05). Hence inputs from cutaneous receptors, muscle receptors, and combined inputs from both receptors likely subserve kinesthesia at joints throughout the body.

Anatomy of the primitive bird Sapeornis chaoyangensis from the Early Cretaceous of Liaoning, China

2003 ◽  
Vol 40 (5) ◽  
pp. 731-747 ◽  
Author(s):  
Zhonghe Zhou ◽  
Fucheng Zhang
Keyword(s):  
Hind Limb ◽  
Feeding Habit ◽  
Pectoral Girdle ◽  
Mosaic Pattern ◽  
Avian Evolution ◽  
New Information ◽  
New Material ◽  
Evolution Of Birds ◽  
Phalangeal Formula ◽  
Basal Position

Two new, nearly completely articulated skeletons of Sapeornis chaoyangensis provide much new information about the anatomy of this basal avian, particularly in the skull, pectoral girdle, forelimb, and hind limb. This new material shows that the hand of Sapeornis, with a phalangeal formula of "2–3–2," was more derived than previously reconstructed. The skeleton of Sapeornis has several unique features, such as a distinctively elongated fenestra on the proximal end of the humerus, a robust furcula with a distinctive hypocleidum, and an elongated forelimb. Sapeornis exhibits a combination of derived and primitive features, including a short, robust non-strut-like coracoid and a fibula reaching the distal end of the tarsal joint (as in Archaeopteryx), a pygostyle, reduced manual digits, and a well-fused carpometacarpus (as in more advanced birds). These features further indicate the mosaic pattern in the early evolution of birds and confirm the basal position of Sapeornis near Archaeopteryx and Jeholornic in the phylogeny of early birds. The preservation of gastroliths in one of the new specimens also represents the first Chinese Mesozoic bird with such evidence, indicating a herbivorous feeding habit and providing further evidence for our understanding of the diet diversification in early avian evolution.

Body composition of Romney-Southdown cross and Merino sheep foetuses at a constant age and a constant body weight

1964 ◽  
Vol 6 (3) ◽  
pp. 309-319 ◽  
Author(s):  
S. K. Stephenson
Keyword(s):  
Growth Rate ◽  
Body Composition ◽  
Body Weight ◽  
Muscle Tissue ◽  
Hind Limb ◽  
Body Shape ◽  
Carcass Composition ◽  
The Body ◽  
Merino Sheep ◽  
Australian Merino

1. Body shape and carcass composition have been measured in a dated series of Romney-Southdown cross and Australian Merino sheep foetuses.2. Large differences in shape exist between the two breed groups and these result from growth rate differences in certain components of the bone and muscle tissue.3. Carcass composition at any particular foetal weight, however, is more uniform. In relation to body weight, the Merino has a higher proportion of bone in the body but the proportion of muscle is the same in both breed groups. Nevertheless, the distribution of muscle tissue is changed as there s i a higher proportion of muscle in the hind limb of the Romney-Southdown cross.

scholarly journals Maniraptoran pelvic musculature highlights evolutionary patterns in theropod locomotion on the line to birds

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10855
Author(s):  
Matthew M. Rhodes ◽  
Donald M. Henderson ◽  
Philip J. Currie
Keyword(s):  
Hind Limb ◽  
Soft Tissues ◽  
Morphological Features ◽  
Fundamental Aspect ◽  
Evolutionary Patterns ◽  
Theropod Dinosaurs ◽  
Relative Differences ◽  
Insight Into

Locomotion is a fundamental aspect of palaeobiology and often investigated by comparing osteological structures and proportions. Previous studies document a stepwise accumulation of avian-like features in theropod dinosaurs that accelerates in the clade Maniraptora. However, the soft tissues that influenced the skeleton offer another perspective on locomotory adaptations. Examination of the pelvis for osteological correlates of hind limb and tail musculature allowed reconstruction of primary locomotory muscles across theropods and their closest extant relatives. Additionally, the areas of pelvic muscle origins were quantified to measure relative differences within and between taxa, to compare morphological features associated with cursoriality, and offer insight into the evolution of locomotor modules. Locomotory inferences based on myology often corroborate those based on osteology, although they occasionally conflict and indicate greater complexity than previously appreciated. Maniraptoran pelvic musculature underscores previous studies noting the multifaceted nature of cursoriality and suggests that a more punctuated step in caudal decoupling occurred at or near the base of Maniraptora.

scholarly journals A neck-like vertebral motion in fish

2021 ◽  
Vol 288 (1957) ◽  
pp. 20211091
Author(s):  
Ariel L. Camp
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Vertebral Column ◽  
Three Dimensional ◽  
The Body ◽  
X Ray ◽  
Control Motion ◽  
Caudal Vertebrae ◽  
Vertebral Kinematics

Tetrapods use their neck to move the head three-dimensionally, relative to the body and limbs. Fish lack this anatomical neck, yet during feeding many species elevate (dorsally rotate) the head relative to the body. Cranial elevation is hypothesized to result from the craniovertebral and cranial-most intervertebral joints acting as a neck, by dorsally rotating (extending). However, this has never been tested due to the difficulty of visualizing and measuring vertebral motion in vivo . I used X-ray reconstruction of moving morphology to measure three-dimensional vertebral kinematics in rainbow trout ( Oncorhynchus mykiss ) and Commerson's frogfish ( Antennarius commerson ) during feeding. Despite dramatically different morphologies, in both species dorsoventral rotations extended far beyond the craniovertebral and cranial intervertebral joints. Trout combine small (most less than 3°) dorsal rotations over up to a third of their intervertebral joints to elevate the neurocranium. Frogfish use extremely large (often 20–30°) rotations of the craniovertebral and first intervertebral joint, but smaller rotations occurred across two-thirds of the vertebral column during cranial elevation. Unlike tetrapods, fish rotate large regions of the vertebral column to rotate the head. This suggests both cranial and more caudal vertebrae should be considered to understand how non-tetrapods control motion at the head–body interface.

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