ABSTRACT. The body mass estimation of several limb bone dimensions (shaft cross-sectional properties, articular sizes, and bone lengths) were examined using bivariate linear regression analyses. The sample included taxonomically and behaviourally diverse small to medium-sized Recent carnivorans and carnivorous marsupials. All examined limb bone dimensions indicated low errors (percentage standard error of estimate, 8±13) for the body mass estimations. Among them, humeral and femoral shaft properties correlated best with body weight, while limb bone lengths gave larger errors. Both humeral and femoral head dimensions have relatively large individual variations, and distal humeral articular dimensions seem to be in¯uenced more by phylogenetic differences. The regressions based on each locomotor group gave slightly lower errors than those based on the total pooled sample. The results were then applied to hyaenodontid creodonts from the Eocene±Oligocene of North America. The estimated body masses (kg) are: Ar®a, 5´4±9´5; Prototomus, <6´0; Pyrocyon, 2´6; Sinopa, 1´3±1´4; Tritemnodon, 7´6±13; Prolimnocyon, 1´6; Thinocyon, 0´7±2´5; Machaeroides, 12; Limnocyon, 7´8± 16; Hyaenodon, 9´1±43. The various limb bone dimensions give different body mass values, but the variation in estimates is smaller compared to those derived from dental or cranial measurements.KEY WORDS: Hyaenodontidae, carnivorous mammals, body mass estimates, limb bone dimensions.

No abstract

No abstract

The biogeography and faunal evolution of middle to late Eocene mammals throughout East Asia is assessed. Appearance Event Ordination was used to get a reliable temporal ordination of 92 Paleogene faunas from East Asia. Results from this analysis are generally consistent with the faunal sequence of traditional East Asian Land Mammal "Ages" (EALMAs). Exceptions are that the Arshantan Fauna fell within Irdinmanhan EALMA faunas, and three latest middle to late Eocene faunas from southern East Asia are misaligned due to high degrees of endemism. Comparison of 30 major middle/late Eocene mammalian faunas at the generic level, using Simpson's Faunal Resemblance Index and the ordinal composition of each fauna indicate that: (1) the differentiation in faunal similarity and composition between northern and southern East Asia started near the middle Eocene-late Eocene boundary; (2) this differentiation is reflected by the decline of perissodactyls and radiation of several artiodactyl clades in the later Eocene of southern East Asia; and (3) in southern East Asia, faunal endemism increased in the later Eocene. The latest middle to late Eocene faunas of the southern area do not fit within the EALMA system, which was primarily established with northern faunas, because of their endemism. Mammalian faunal changes actually seem to have begun much earlier in the southern region of East Asia than in the northern part, so the faunal changes toward the end of the Eocene in East Asia were not synchronous. Faunal changes during the Eocene-Oligocene transition in southern East Asia seem not to have been controlled by global climatic changes.

No abstract