The gaits of five Ostriches Struthio camelus, seven Emus Dromaius novaehollandiae, two Greater Rheas Rhea americana, two Southern Cassowaries Casuarius casuarius and one Brown h w i Apteryx australis were filmed a t zoological parks. Locomotor parameters were measured using footprints on sandy tracks and video records. Osteological measurements

ABSTRACT. The burrowing process of the common mole Talpa europaea Linnaeus, 1758 was investigated by the cinefluorography. During burrowing the humerus is abduced only on 2530°. This abduction is realized by the rotation of the scapula around its longitudinal axis and by the translation of the clavicle in the sternoclavicular and claviculohumeral joints. The abduction of the shoulder joint is limited to 1015° by nearly complete coincidence of the articular surfaces of the scapular glenoid fossa and the humeral head. The shoulder joint extension diminishes the abductors momentum on 3070% and in this case they cannot develop the force determined in the experiments. M. flexor digitorum profundus is transformed in the ligament which origins on the median epicondyle of humerus and inserts on all the five ungual phalanges. This is an unique mechanism for the neutralization pronation momentum of the humerus abductors. The increasing of the pressure of the hands on the soil augments the tension of the m. flexor digitorum profundus what hinders the pronation of the humerus. The increasing of the rotation of the antebrachium is necessary to maintain the hand in a parasagittal plane. An accretion of the humeral median epicondyle promotes decreasing of the humerus rotation. Humerus rotates during terrestrial locomotion in all tetrapods with sprawling limb position (humerus pronates in the propulsive phase and supinates in the swing phase). The recent Monotremata and probably primitive mammals use the humerus pronation for the lengthening of the stride. Mm. supraspinatus and infraspinatus prevent the humerus retraction. The widening of the humerus in these mammals is an adaptation to its rotation by the limited abduction and retraction. On the contrary, the widening of humerus in moles is an adaptation to its abduction by the limited rotation. Thus the convergent widening of the humerus in these animals is caused by the diametrically opposite functions.

No abstract

Seven juvenile individuals of the Australian species Crocodylus johnstoni from the Frankfurt Zoological Park were ®lmed on high-speed video, at 250 ®elds s 71 , whilst freely moving at various speeds in a long corridor. The sequences of locomotion were analysed to determine the various space and time parameters to characterize limb kinematics. We found that the animals use diverse patterns of asymmetrical gait, revealing great¯exibility in limb co-ordination. In all these gaits, the forelimb strikes the ground ®rst, in the couple made by diagonally opposite fore-and hindlimbs. Among these gaits, rotary gallop offers probably a high level of manoeuvrability, whereas transverse gallop resulted in a higher level of stability. Speed increase is achieved by half-bound and bound, the latter being the only gait used at velocities > 2 m s 71 . Speed was increased mainly by increasing the stride length of the fore-and hindlimbs by simultaneously increasing both its components, the step and swing lengths. However, in bound, the step length of each forelimb increased more than the swing length, resulting in a stronger thrust action, whereas swing length increased more than step length for the hindlimb, causing the centre of mass to accelerate forwards during its ballistic phase. The asymmetrical gaits of crocodiles such as Crocodylus johnstoni are probably not functionally equivalent to the transitional asymmetrical gaits exhibited by lizards when building up into a bipedal run. These gaits are also not entirely equivalent to mammalian gaits, despite the use of vertical movements of the vertebral axis in these crocodiles, favouring an erect dynamic posture.

The aim of this study was to identify shape patterns of the shoulder girdle in relation to different functional and environmental behaviours in turtles. The Procrustes method was used to compare the shoulder girdles (scapula and coracoid) of 88 adult extant turtles. The results indicate that four shape patterns can be distinguished. The shoulder girdles of (1) terrestrial (Testudinidae), (2) highly aquatic freshwater (Trionychidae, Carettochelyidae) and (3) marine turtles (Cheloniidae, Dermochelyidae) correspond to three specialized morphological patterns, whereas the shoulder girdle of (4) semi-aquatic freshwater turtles (Bataguridae, Chelidae, Chelydridae, Emydidae, Kinosternidae, Pelomedusidae, Platysternidae, Podocnemididae) is more generalized. In terrestrial turtles, the long scapular prong and the short coracoid are associated with a domed shell and a mode of locomotion in which walking is predominant.By contrast, highly aquatic freshwater turtles share traits with marine turtles. In both, the short scapular prong and the long coracoid are associated with a flat shell, and swimming locomotion. The enlarged attachment sites of the biceps, coracobrachialis magnus, and supracoracoideus also give these strong swimmers a mechanical advantage during adduction and retraction of the arm. Increasing size leads to allometrical shape changes that emphasize mechanical efficiency both in terrestrial and in aquatic turtles.

The gaits of the adult SWISS mice during treadmill locomotion at velocities ranging from 15 to 85 cm s(-1) have been analysed using a high-speed video camera combined with cinefluoroscopic equipment. The sequences of locomotion were analysed to determine the various space and time parameters of limb kinematics. We found that velocity adjustments are accounted for differently by the stride frequency and the stride length if the animal showed a symmetrical or an asymmetrical gait. In symmetrical gaits, the increase of velocity is provided by an equal increase in the stride length and the stride frequency. In asymmetrical gaits, the increase in velocity is mainly assured by an increase in the stride frequency in velocities ranging from 15 to 29 cm s(-1). Above 68 cm s(-1), velocity increase is achieved by stride length increase. In velocities ranging from 29 to 68 cm s(-1), the contribution of both variables is equal as in symmetrical gaits. Both stance time and swing time shortening contributed to the increase of the stride frequency in both gaits, though with a major contribution from stance time decrease. The pattern of locomotion obtained in a normal mouse should be used as a template for studying locomotor control deficits after lesions or in different mutations affecting the nervous system.

Digging locomotion of Namib Golden moles has been studied by making X–ray cinematograph films, and the morphology of their locomotor system investigated by means of radiographs and dissections. Biomechanical interpretations of the data so obtained show that moving forwards results from a cyclical compacting and decompacting of the surrounding sand. The whole step–cycle IS made up of a buttressing phase followed by several digging propulsion phases.

Exceptional fossilization of large tetrapod swimming traces occurs in the Cerin Lagerstätte (Jura Mountains, France). These trackways are imprinted in Jurassic (Late Kimmeridgian) lagoonal fine‐grained limestones and are attributed to giant turtles, which swam with a simultaneous movement of their forelimbs like the modern ones. These turtles swam in very shallow waters close to land, perhaps near a nesting area. As a major consequence, these new ichnologic data place the origin of true large marine turtles during the Jurassic period and not during the Cretaceous period as previously considered on the basis of skeletal remains.