Kangaroo morphometrics: how Miocene kangaroos can inform us about palaeoenvironments and how giant Pleistocene kangaroos managed to locomote

Kangaroos are known today for their spectacular hopping locomotion, but kangaroo diversity in the past tells a different story. Some kinds of extinct kangaroos (sthenurines) grew so large that hopping would seem to be unlikely. Analysis of their bones shows that it is likely that they used walking on two legs as a means of getting around. The diversity of small kangaroos in the Miocene can inform us about palaeoenvironments, and how the higher levels of both temperature and atmospheric carbon dioxide in the middle Miocene affected the evolution of both fauna and flora.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Locomotion in extinct giant kangaroos: were sthenurines hop-less monsters?

The extinct \u27sthenurine\u27 family of giant Kangaroos, up to three times larger than living Kangaroos, were able to walk on two feet, according to new research. Abstract Sthenurine kangaroos (Marsupialia, Diprotodontia, Macropodoidea) were an extinct subfamily within the family Macropodidae (kangaroos and rat-kangaroos). These “short-faced browsers” first appeared in the middle Miocene, and radiated in the Plio-Pleistocene into a diversity of mostly large-bodied forms, more robust than extant forms in their build. The largest (Procoptodon goliah) had an estimated body mass of 240 kg, almost three times the size of the largest living kangaroos, and there is speculation whether a kangaroo of this size would be biomechanically capable of hopping locomotion. Previously described aspects of sthenurine anatomy (specialized forelimbs, rigid lumbar spine) would limit their ability to perform the characteristic kangaroo pentapedal walking (using the tail as a fifth limb), an essential gait at slower speeds as slow hopping is energetically unfeasible. Analysis of limb bone measurements of sthenurines in comparison with extant macropodoids shows a number of anatomical differences, especially in the large species. The scaling of long bone robusticity indicates that sthenurines are following the “normal” allometric trend for macropodoids, while the large extant kangaroos are relatively gracile. Other morphological differences are indicative of adaptations for a novel type of locomotor behavior in sthenurines: they lacked many specialized features for rapid hopping, and they also had anatomy indicative of supporting their body with an upright trunk (e.g., dorsally tipped ischiae), and of supporting their weight on one leg at a time (e.g., larger hips and knees, stabilized ankle joint). We propose that sthenurines adopted a bipedal striding gait (a gait occasionally observed in extant tree-kangaroos): in the smaller and earlier forms, this gait may have been employed as an alternative to pentapedal locomotion at slower speeds, while in the larger Pleistocene forms this gait may have enabled them to evolve to body sizes where hopping was no longer a feasible form of more rapid locomotion

A study of resources and support needed for families of students receiving special education services.

The purpose of this study was to identify the use of resources and support needed by families of children with disabilities. The study also examined the perceptions of importance regarding resources and support by families of children with disabilities, the relationship of size of the school district and use and perceptions of importance of resources and the relationships of time since initial identification of the child\u27s disability and the use and perceptions of importance of resources and support. This quantitative study used Hornby\u27 s (1975) theoretical model for parental involvement for the development of a survey that was administered to parents of children with disabilities. The design of the survey instrument was organized around four areas: communication, liaison/advocacy, education and support. Parents of children with disabilities within the geographical area of Loess Hills Area Education Agency in southwest Iowa identified levels of usage and perceptions of importance. The responses to the survey were analyzed using frequency distributions, one-way analysis of variances (ANOVAs), and Pearson product-moment correlation coefficients. The results of this study were: (1) fifteen resources and support systems have varying levels of usage by parents of children with disabilities; (2) seventeen resources and support systems have varying perceptions of importance of need by parents of children with disabilities; (3) size of the school district did not result in a statistically significant difference in use and perceptions of importance, except for categories related to communication with other parents of children with disabilities and use of school personnel for information; and (4) the time since the initial identification of the disability did not result in a statistically significant difference in parents\u27 use and perception of importance of resources and support systems. The information gained from this study was useful to school districts and other service providers who collaborate with parents of children with disabilities in meeting their needs

Protect My Future: The Links Between Child Protection and Disasters, Conflict and Fragility in the Post-2015 Development Agenda

In this paper, we examine the implications of this lack of prioritisation for the post-2015 development framework, arguing that this framework must include a goal and target on child protection that applies to both fragile and non-fragile states, and makes specific reference to emergency contexts. Since 2000, 2.3 billion people have been directly affected by disasters and in 2011 alone almost 200 million people were affected, including 100 million children (Gupa-Sapir, Santos and Bordre 2013). Conflict, disasters and fragility have devastating effects on children's lives, and have contributed to the wider global crisis in child protection. For example, children may become separated from families during crisis periods or exposed to violence, abuse and child labour as a consequence of the impact of conflict and disasters on household poverty and livelihood practices, and in conflict situations, children are often forced to join armed forces or groups (CPWG 2012; Child Soldiers International 2012). Fragile states commonly lack even basic effective child protection measures, and children are at particular risk of many forms of abuse and exploitation in such settings (World Vision 2012). Despite the heightened vulnerability of girls and boys during and after conflict and disasters, currently humanitarian action does not give adequate priority to child protection and care, a situation that reflects the broader lack of attention given to this important issue in fragile and non-fragile states

Cranial and postcranial morphological data in ruminant phylogenetics

While the identity and validity of the extant families of ruminants are undoubted, there are significant problems with the determination of the interrelationships among the families, notably within the families of the Pecora, or horned ruminants. The morphological features used to construct ruminant phylogeny have been a source of controversy: many features used over the past century have been shown to be highly homoplastic and related to functional similarities. Ruminants evolved in the context of the later Cenozoic climatic changes, and many lineages adopted functional morphological adaptations related to feeding on more abrasive diets (resulting in the parallel evolution of a greater extent of loph development in the molars and, in some lineages, hypsodonty) and locomotion in open habitats (resulting in the parallel evolution of fused metapodials and reduction and/or loss of lateral digits). The fact that the molecular phylogeny shows a very different pattern from the currently accepted morphological one is of particular cause for concern, especially as molecular data are of no use for understanding the relationships of extinct lineages. Here we review the morphological data used in ruminant phylogenetics, and show even many of the less obviously functional features (e.g., number and position of the lacrimal orifices) are subject to homoplasy and variation, especially when fossil taxa are included. In addition, many morphological features treated as independent traits in phylogenetics are correlated (e.g., cranial morphology associated with hypsodonty). Some potentially reliable features are identified, but these do not help to sort out relationships within the Pecora. We advocate for the investigation into better morphological features, possibly derived from basicranial and ear region characters (although these features are not without their own issues of homoplasy), and for caution in character consideration in performing phylogenetic analyses

The Evolution of Equid Monodactyly: A Review Including a New Hypothesis

The traditional story of horse evolution is well-known: over time, horses became larger, they attained higher-crowned teeth, and they changed from having three toes (tridactyly) to a single toe (monodactyly). Evolution is often perceived as a progression toward some optimum outcome, in this case the “Noble Steed.” However, the evolutionary advantages of monodactyly are not entirely clear, other than the notion that it must somehow be “more efficient,” especially at the larger body size of the genus Equus. It is not commonly appreciated that the reduction of the digits to the monodactyl condition was not the main anatomical foot transition in equid history. Rather, the most important change was the transformation of the original “pad foot” into the more derived “spring foot,” with the acquisition of an unguligrade limb posture, characteristic of the family Equinae. Species within the Equinae tribes—Hipparionini, Protohippini, and Equini—evolved hypsodont teeth and diverged into both small and large body sizes, but monodactyly evolved only within the Equini. Despite the Plio-Pleistocene success of Equus, Hipparionini was by far the richest tribe for most of the Neogene, in terms of taxonomic diversity, numbers of individuals, and biogeographic distribution; but hipparionins remained persistently tridactyl over their duration (17–1 Ma). We propose that the adaptive reasons for monodactyly must be considered in the context of reasons why this morphology never evolved in the Hipparionini. Additionally, Equus inherited monodactyly from smaller species of Equini, and consideration of Miocene taxa such as Pliohippus is critical for any evolutionary hypothesis about the origins of monodactyly. We review the literature on equid locomotor biomechanics and evolution, and propose two novel hypotheses. (1) The foot morphology of derived Equini is primarily an adaptation for increasing locomotor efficiency via elastic energy storage, and the accompanying digit reduction may be circumstantial rather than adaptive. (2) Differences in foraging behavior and locomotor gait selection in Equini during late Miocene climatic change may have been a prime reason for the evolution of monodactyl horses from tridactyl ones