The most complete account of the hind leg muscles of the kiwi was published a century ago by Sir Richard Owen, in his seventy-fifth year. This extensively-cited work has several omissions and errors, and while certain of these were corrected by subsequent authors, sufficient uncertainty remains to warrant a reinvestigation. In the present study a detailed description of the hind leg musculature is given, based upon dissections of two frozen specimens. An indication of the possible function of each muscle is given by assessing its size, action, and fiber-arrangement, together with tentative data on the relative abundance of twitch and tonus fibers. The correlation between surface features of bones and muscle attachments is investigated with a view to interpreting palaeontological material. Although the limb and pelvic bones are marked by numerous features which suggest muscle attachments, relatively few can be positively identified with specific muscles. Only 23% of the muscle origins and insertions can be identified, and, with three possible exceptions, no indication of relative size is given by the scars. The possibility of being able to reconstruct the musculature of the kiwi from its skeletal anatomy, much less that of its extinct relatives, is remote.

A study of 60 latipinnate ichthyosaurs from the English Lower Lias (Lower Jurassic) reveals only four valid species; Ichthyosaurus communis Conybeare, /. breviceps Owen, /. conybeari Lydekker, and /. tenuirostris Conybeare. Emended diagnoses and descriptions are given. /. communis, a medium-sized ichthyosaur reaching a maximum length of about 2.5 m, is the commonest species. /. tenuirostris, of similar size to /. communis, is less common and characterized by extreme snout length. /. breviceps, a small species with a maximum recorded body length of 1.3 m, is scarce and is characterized by an abbreviated snout. The rarest latipinnate is /. conybeari, with only two individuals known. Both are small, with an estimated body length of 1.3 m in the larger individual. The snout is long, slender, and sharply pointed, and the orbit appears to be relatively large. Zusammenfassung Eine Studie iiber 60 latipinnate Ichthyosaurier aus dem englischen unteren Lias (Unterer Jura) ergibt nur vier giiltige Arten; Ichthyosaurus communis Conybeare, /. breviceps Owen, /. conybeari Lydekker, /. tenuirostris Conybeare. Verbesserte Diagnosen und Beschreibungen werden gegeben. /. communis, die gewohnlichste Art, ist ein mittelgrosser Ichthyosaurier, welcher eine Lange von ungefahr 2.5 Meter erreicht. /. tenuirostris, von ungefahr derselben Grosse wie /. communis, ist seltener und zeichnet sich durch seine ungewohnlich lange Schnauze aus. /. breviceps, eine kleine Art, mit einer Lange bis zu 1.3 Meter, ist sehr selten und zeichnet sich durch seine verkiirzte Schnauze aus. Die seltenste Art ist /. conybeari, von welcher nur zwei Exemplare bekannt sind. Beide sind klein, das grossere Exemplar hat eine abgeschatzte Lange von 1.3 Meter. Die Schnauze ist lang, schmal, scharf zugespitzt, und die Augenhohlen scheinen verhaltnismassig gross zu sein. /. tenuirostris Conybeare. Results of the statistical analyses are shown in Tables 1 and 2, and their size ranges are shown in Fig. 1.

A revision of the longipinnate ichthyosaurs of the English Lias (Lower Jurassic) estabhshes five valid species. One of these is referred to the Upper Liassic genus Stenopterygius, the others to the genus Temnodontosaurus Lydekker, 1889, which is predominantly Lower Liassic in age. Two new Lower Liassic species are described. A detailed account of the variates measured is given. Zusammenfaasung Eine Revision der longipinnaten Ichthyosaurier des englischen Lias (Untere Jura) stellt fuenf gueltige Arten auf. Eine von diesen bezieht sich auf die aus dem oberen Lias stammende Gattung Stenopterygius, die anderen auf die Gattung Temnodontosaurus Lydekker, 1889, welche ueberwiegend aus dem unteren Lias stammt. Ein ausfuehrhcher Bericht ueber die gemmessenen Verschiedenheiten wird gegeben.

A large ichthyosaur, with a total length in excess of 7 m, is described from the Lower Jurassic (Sinemurian) of Dorset, England. Like Leptopterygius tenuirostris the new species, named Leptopterygius solei, has a long slender snout armed with slender teeth that are remarkably small for the large size of the skull. There are also similarities in the forefin: the humerus is widely expanded distally, and the phalanges are rounded rather than polygonal and are probably well spaced distally. However, in contrast to L. tenuirostris, there is no notch on the leading edge of the radius. The snout is also relatively shorter and the orbit smaller. Thus in the holotype the estimated values for the snout and orbital ratios are 0.68 and 0.15 respectively, compared with observed ranges for L. tenuirostris of 0.71–0.76 (n = 7) and 0.18–0.24 (n = 7). Leptopterygius solei also has a somewhat higher prepelvic vertebral count, being at least 50 in the holotype compared with an observed range of 44–48 (n = 9) for L. tenuirostris. Furthermore, the ischium is considerably wider than the pubis, whereas these elements have approximately similar widths in L. tenuirostris. The possibility that the new material might merely represent the upper end of a growth series of L. tenuirostris is dismissed. Based on skull length, the holotype of L. solei is 66% larger than the largest specimen of L. tenuirostris.

Most previous accounts of the wing muscles of the kiwi have only dealt with the proximal muscles. The few accounts that have treated the distal muscles are incomplete in other respects and sufficient uncertainty exists to warrant the present study. The wing musculature of the kiwi is closely similar to that of other ratites but markedly dissimilar to that of the carinates. In this regard the wing muscles differ from those of the leg. Ratites have far fewer wing muscles than carinates. Significantly, they lack propatagial muscles (and almost certainly propatagia), and neither the M. pectoralis nor the M. supracoracoideus is well developed; in carinates these two flight muscles comprise the bulk of the wing musculature. Furthermore, the insertion tendon of the M. supracoracoideus does not loop through a triosseal canal to effect wing elevation as it does in the carinates. In all of these regards the ratite condition is closer to that of reptiles than of carinates. This raises the question of whether ratites should be regarded as primitive birds, rather than as advanced birds that evolved from carinates. The present skeleto‐muscular data, taken with other evidence, suggests that ratites are primitive birds that evolved from a primitive, volant ancestor. The elements of the pectoral skeleton show a greater degree of individual variation than those of the pelvic skeleton. Aside from its extreme curvature the humerus is the most rudimentary element and few of its features can be compared with those of the carinate humerus. Few of the wing muscles have attachments that can be identified with specific osteological features. Myological data for the kiwi are therefore virtually irretrievable from osteological material, as noted previously for the pelvic muscles. While this might be peculiar to the kiwi (which seems unlikely) the fact should serve as a cautionary note to palaeontologists attempting to reconstruct the muscles of extinct animals.