Mammalian Skeleton Research Articles

Life and death in a Late Cretaceous dune field, Nemegt basin, Mongolia

For more than 70 years, red sandstones of the Gobi Desert have yielded abundant articulated skeletons of Late Cretaceous dinosaurs, lizards, and mammals. At Ukhaa Tolgod, structureless sandstones are the only fossiliferous facies, and we present new evidence for deposition on dune-sand–sourced alluvial fans that were built at the margins of stabilized eolian bedforms during mesic climatic episodes. In laterally and vertically adjacent large-scale eolian cross-strata in which skeletons are absent, we have found abundant tracks of dinosaurs that walked on sparsely vegetated dunes that were active under xeric conditions. Our study of calcareous concretions in vaguely bedded eolian sandstones suggests that bedding was nearly destroyed by burrowing invertebrates and trampling dinosaurs. The accumulation of illuvial clays and pedogenic calcite in these sediments reduced infiltration of rainwater and, with attendant climatic change and heavy rainfall events, led to fan development.

Levels of Homoplasy in the Evolution of the Mammalian Skeleton

It is commonly believed that there are differences in the evolutionary lability of the crania, dentition, and postcrania of mammals, the latter two being more prone to homoplasy because of strong selective pressures for feeding and locomotion, respectively. Further, because of the fragmentary nature of fossils, phylogenetic analyses of extinct taxa often must utilize characters based on only one of these systems. In this paper the levels of homoplasy (as measured by the consistency index; CI) were compared in characters based on these three anatomical systems in therian mammals. No statistically significant differences were found in the overall CIs of 41 data sets based on dental, cranial, or postcranial characters. Differences in homoplasy within data sets with two or three kinds of data were not statistically significant. These findings suggest that dental, cranial, and postcranial characters can be equally prone to homoplasy and none should be automatically dismissed, disregarded, or systematically weighted in phylogenetic analyses. The level of homoplasy in characters derived from a given region of the skeleton may differ depending on the taxonomic level of the taxa considered. Dental, cranial, and postcranial characters may not constitute “natural” classes, yet examination of the phylogenetic signal of these subsets of data previous to a simultaneous analysis can shed light on significant aspects of the evolutionary process.

A new symmetrodont mammal from China and its implications for mammalian evolution.

A new symmetrodont mammal has been discovered in the Mesozoic era (Late Jurassic or Early Cretaceous period) of Liaoning Province, China. Archaic therian mammals, including symmetrodonts, are extinct relatives of the living marsupial and placental therians. However, these archaic therians have been mostly documented by fragmentary fossils. This newfossil taxon, represented by a nearly complete postcranial skeleton and a partial skull with dentition, is the best-preserved symmetrodont mammal yet discovered. It provides a new insight into the relationships of the major lineages of mammals and the evolution of the mammalian skeleton. Our analysis suggests that this new taxon represents a part of the early therian radiation before the divergence of living marsupials and placentals; that therians and multituberculates are more closely related to each other than either group is to other mammalian lineages; that archaic therians lacked the more parasagittal posture of the forelimb of most living therian mammals; and that archaic therians, such as symmetrodonts, retained the primitive feature of a finger-like promontorium (possibly with a straight cochlea) of the non-therian mammals. The fully coiled cochlea evolved later in more derived therian mammals, and is therefore convergent to the partially coiled cochlea of monotremes.

BMP7 Null Mutation in Mice: Developmental Defects in Skeleton, Kidney, and Eye

While generatingbcl2α transgenic mice, we found some F2 offspring of one of the transgenic lines which were very small and had closed eyes at the time of weaning. These pups died within 1 month after birth. In order to determine the molecular basis of this phenotype, we screened a genomic library of the above transgenic line with a transgene-specific probe and found that theBmp7gene, a member of the TGFβ superfamily, was inactivated by insertional mutagenesis due to transgene integration. TheBmp7homozygous null condition in mice is a postnatal lethal mutation and is associated with various developmental defects: holes in the basisphenoid bone and the xyphoid cartilage, retarded ossification of bones, fused ribs and vertebrae, underdeveloped neural arches of the lumbar and sacral vertebrae, polydactyly of the hind limbs, a kinked tail, a reduced number of nephrons, polycystic kidney, lack of retinal pigmentation, and retarded lens development. These findings indicate that BMP7 is an important signaling molecule for normal development of the mammalian skeleton, kidney, and eye.

Do arctic-breeding Red Knots (Calidris canutus) accumulate skeletal calcium before egg laying?

Earlier studies have indicated that the diet of egg-laying female birds which eat only terrestrial arthropods has to be supplemented with calcium if they are to produce high-quality eggshells without interruption. During egg laying, females of tundra-breeding shorebird species may supplement their diet with fragments of mammalian skeletons, but as an alternative strategy they might store skeletal calcium before egg formation. We examine the possibility of calcium storage on the basis of temporal changes in the ash mass (a good indicator of skeletal mass) of male and female Red Knots (Calidris canutus islandica) collected during their stopover in Iceland in May and July, and after arrival on the breeding grounds in northernmost Ellesmere Island, Canada, in late May and early June. Significantly higher ash masses of females than of males, an increase in ash mass of females before the period of egg formation in mid-June in combination with a subsequent decrease, and the notable absence of temporal changes in ash mass of males, lead us to propose that female Red Knots do store skeletal calcium before egg laying. The rate of calcium storage would be 2.3 times higher after arrival on Ellesmere Island than during the stopover in Iceland, but the dietary components through which storage is achieved remain unclear. With an almost 50% change in the skeletal mass of females, Red Knots currently hold the record with respect to skeletal calcium dynamics in free-living egg-laying birds. The stored skeletal mass would allow them to produce at least half the clutch without further calcium intake.

Primary Structure and Tissue Distribution of FRZB, a Novel Protein Related to Drosophila Frizzled, Suggest a Role in Skeletal Morphogenesis

Articular cartilage extracts were prepared to characterize protein fractions with in vivo chondrogenic activity (Chang, S., Hoang, B., Thomas, J. T., Vukicevic, S., Luyten, F. P., Ryba, N. J. P., Kozak, C. A., Reddi, A. H., and Moos, M. (1994) J. Biol. Chem. 269, 28227-28234). Trypsin digestion of highly purified chondrogenic protein fractions allowed the identification of several unique peptides by amino acid sequencing. We discovered a novel cDNA encoding a deduced 36-kDa protein by using degenerate oligonucleotide primers derived from a 30-residue peptide in reverse transcription polymerase chain reactions. Its N-terminal domain showed approximately 50% amino acid identity to the corresponding region of the Drosophila gene frizzled, which has been implicated in the specification of hair polarity during development. Hydropathy and structural analyses of the open reading frame revealed the presence of a signal peptide and a hydrophobic domain followed by multiple potential serine/threonine phosphorylation sites and a serine-rich C terminus. Cell fractionation studies of primary bovine articular chondrocytes and transfected COS cells suggested that the protein is membrane-associated. In situ hybridization and immunostaining of human embryonic sections demonstrated predominant expression surrounding the chondrifying bone primordia and subsequently in the chondrocytes of the epiphyses in a graded distribution that decreased toward the primary ossification center. Transcripts were present in the craniofacial structures but not in the vertebral bodies. Because it is expressed primarily in the cartilaginous cores of developing long bones during embryonic and fetal development (6-13 weeks) and is homologous to the polarity-determining gene frizzled, we believe that this gene, which we named frzb, is involved in morphogenesis of the mammalian skeleton.

Detection limits of absorbed dose of ionizing radiation in molluscan shells as determined by e.p.r. spectroscopy

The exposure of waters to ionizing radiation from radionuclides imprisoned in dumped nuclear waste containers, freed in nuclear submarine accidents or released in underwater magma eruptions are difficult to be evaluated by conventional radiometric methods. Ionizing radiation evokes stable paramagnetic centers in crystalline lattice of mineral components in bone skeletons of mammals and fishes as well as in exoskeletons of mollusca. They give rise in e.p.r. to specific, extremely stable signals which are proposed to be applied as indicators of radiation exposure levels. In present study the e.p.r. detection limits of the dose of ionizing radiation absorbed in shells of fresh water and marine mollusca (selected species) have been estimated. It has been found that with fresh water mollusca the dose of 1–2 Gy can be detected, while the sea water mollusca by one order of magnitude lower, i.e. about 0.1 Gy.

Cretaceous multituberculate skeleton and the early evolution of the mammalian shoulder girdle

A Cretaceous eucosmodont multituberculate mammal skeleton has been found in Mongolia with all of the bony elements of the shoulder girdle in place. This specimen demonstrates a different forelimb stance from that recently hypothesized for another Cretaceous eucosmodont. Primitively, it retains a separate ossified inter-clavicle, as in monotremes and non-mammalian cynodonts. In other respects it shares with therians and their extinct allies key features associated with mobility of the pectoral girdle and shoulder joint during locomotion, and a more parasagittal forelimb posture. This locomotor transformation appears to have evolved just once among the common ancestors of multituberculates and therians, some time before the Late Jurassic.

The Clavicle of Newborn Dogs

Cern y H., S. C i z i na u sk a s: The Clavicle of Newborn Dogs. Acta vet. Brno 1995,64: 139-145. The morphology, topography and structure of the clavicle and its adnexa, forming together the clavicular complex, were investigated in 21 newborn dogs of both sexes and various breeds by dissection, radiography and histological techniques. The reduced clavicle, I to 2 mm in size, was oval in most cases. Horseshoe-shaped and annular clavicles were less frequent. The clavicle was located outside the clavicular intersection being linked with it by a fascicle of collagenous fibres. A similar fascicle linked the clavicle with the caudal margin of the scapula. No links of the clavicle with the sternum or the perimysium of the pectoral muscles were observed in the early postnatal period. The histological pattern was typical of desmogenic ossification. Osteoid and osseous trabeculae formed an incoherent cortical surface lamella and the formation of a cavity was evident in the centre of the clavicle. The osseous trabeculae aimed radially forming an anastomosing network. The surface of the clavicle was covered by a coherent layer of connective tissue with arranged fascicles of collagenous fibres which, on both ends of the clavicle, passed continuously into fibrous fascicles connecting the clavicle with the surrounding structures and forming together a functional unit. An oval basis of an embryonic cartilage, which we considered to be the preclavium, was observed at the sternal end of the clavicle in more than one half of the dogs. The function of the markedly reduced canine clavicle in the early postnatal period, in which the formation of the associated structures is not yet influenced by locomotion, is discussed. We assume that some of the links joining the clavicle with the adjacent structures develop only after birth in dependence on the locomotion. Newborn dog, early postnatal ontogenesis, clavicle, junction, morphology, ossification The clavicle is one of the components of the bone skeleton of the pectoral girdle connecting the scapula with the sternum. Its primary function is to reinforce the moving extremity. In most mammalian species, the clavicle develops as an important element of the skeleton. On the other hand, it is subject to regression in other species and its function has become limited with the advancing adaptation. The phylogenetic transformation of the skeleton of the pectoral girdle is causally linked with the development of locomotion. The accelerating locomotion and the increased motility of mammals were associated with the turning of both limbs towards the trunk. The limbs aim ventrally and the trunk is hung on them. The change of the overall arrangement of the mammalian skeleton was accompanied by a reduction of the ventral part of the pectoral girdle skeleton consisting of the coracoid and the clavicle, while the dorsal part, i.e. the scapula, has developed fully. The supportive function of the ventral part of the mammalian pectoral girdle skeleton has been taken on by a single bone - the clavicle. The coracoid has disappeared as a separate bone and persists as a vestigial prominence (processus coracoideus) of the scapula. The advancing regressive development has affected the clavicle which is found as a markedly reduced and very small bone in some mammalian species and has become extinct in others. Various degrees of the clavicular regression can be observed in Ungulata, Carnivora, Cetacea, and Sirenia (S tar c k 1979).

Comparison of 1/8″- and 1/4″-Mesh Recovery of Controlled Samples of Small-to-Medium-Sized Mammals

Most previous screen experiments have assessed various mesh-size biases in the recovery of faunal remains from specific archaeological samples. These tests provided detailed information about recovery biases at those sites. To augment these previous tests, Shaffer (1992) conducted 1/4″-screen tests on modern comparative mammal skeletons to assess specific biases for the taxa tested. However, because 1/8″ screens are now widely used in archaeological sampling, potential biases should be assessed. Results presented here document hypothetical best recovery of the taxa tested and substantial increased recovery of mammals weighing between 18 and 340 g for 1/8″-screen tests relative to 1/4″-screen tests.

Limb alterations in brachypodism mice due to mutations in a new member of the TGF beta-superfamily.

The mutation brachypodism (bp) alters the length and number of bones in the limbs of mice but spares the axial skeleton. It illustrates the importance of specific genes in controlling the morphogenesis of individual skeletal elements in the tetrapod limb. We now report the isolation of three new members of the transforming growth factor-beta (TGF-beta) superfamily (growth/differentiation factors (GDF) 5,6 and 7) and show by mapping, expression patterns and sequencing that mutations in Gdf5 are responsible for skeletal alterations in bp mice. GDF5 and the closely related GDF6 and GDF7 define a new subgroup of factors related to known bone- and cartilage-inducing molecules, the bone morphogenetic proteins (BMPs). Studies of Bmp5 mutations in short ear mice have shown that at least one other BMP gene is also required for normal skeletal development. The highly specific skeletal alterations in bp and short ear mice suggest that different members of the BMP family control the formation of different morphological features in the mammalian skeleton.

An Interview with Sherwood Washburn

Previous articleNext article No AccessReportsAn Interview with Sherwood WashburnIrven De Vore, and Sherwood WashburnIrven De Vore Search for more articles by this author , and Sherwood Washburn Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Current Anthropology Volume 33, Number 4Aug. - Oct., 1992 Sponsored by the Wenner-Gren Foundation for Anthropological Research Article DOIhttps://doi.org/10.1086/204093 Views: 12Total views on this site Citations: 20Citations are reported from Crossref Copyright 1992 The Wenner-Gren Foundation for Anthropological ResearchPDF download Crossref reports the following articles citing this article:Erin P. Riley The Maturation of Ethnoprimatology: Theoretical and Methodological Pluralism, International Journal of Primatology 39, no.55 (Oct 2018): 705–729.https://doi.org/10.1007/s10764-018-0064-4Peter Sachs Collopy RACE RELATIONSHIPS: COLLEGIALITY AND DEMARCATION IN PHYSICAL ANTHROPOLOGY, Journal of the History of the Behavioral Sciences 51, no.33 (May 2015): 237–260.https://doi.org/10.1002/jhbs.21728Jarod M. Hutson Neotaphonomic measures of carnivore serial predation at Ngamo Pan as an analog for interpreting open-air faunal assemblages, Journal of Archaeological Science 39, no.22 (Feb 2012): 440–457.https://doi.org/10.1016/j.jas.2011.09.032Daniel Schmitt Translating Primate Locomotor Biomechanical Variables from the Laboratory to the Field, (Oct 2010): 7–27.https://doi.org/10.1007/978-1-4419-1420-0_2 Introduction, (Jan 2010): 1–17.https://doi.org/10.1215/9780822391630-001 Wild West Anthropology and the Disciplining of Gender, (Jan 2010): 18–51.https://doi.org/10.1215/9780822391630-002 Race and the Culture of Anthropology, (Jan 2010): 52–73.https://doi.org/10.1215/9780822391630-003 The Interventions of Culture, (Jan 2010): 74–102.https://doi.org/10.1215/9780822391630-004 Is There A Structural Analysis of Racism?, (Jan 2010): 103–130.https://doi.org/10.1215/9780822391630-005 India in South Africa, (Jan 2010): 131–163.https://doi.org/10.1215/9780822391630-006 Legacies of Culture, Languages of the State, (Jan 2010): 164–188.https://doi.org/10.1215/9780822391630-007 Gendered States, (Jan 2010): 189–212.https://doi.org/10.1215/9780822391630-008 Epilogue, (Jan 2010): 213–225.https://doi.org/10.1215/9780822391630-009 Notes, (Jan 2010): 227–282.https://doi.org/10.1215/9780822391630-010 Bibliography, (Jan 2010): 283–317.https://doi.org/10.1215/9780822391630-011Russell H. Tuttle Obituaries, American Anthropologist 102, no.44 (Dec 2000): 865–869.https://doi.org/10.1525/aa.2000.102.4.865Jonathan Marks Sherwood Washburn, 1911-2000, Evolutionary Anthropology: Issues, News, and Reviews 9, no.66 (Jan 2001): 225–226.https://doi.org/10.1002/1520-6505(2000)9:6<225::AID-EVAN1000>3.0.CO;2-GKamala Visweswaran Race and the Culture of Anthropology, American Anthropologist 100, no.11 (Mar 1998): 70–83.https://doi.org/10.1525/aa.1998.100.1.70Jonathan Marks Blood will tell (won't it?): A century of molecular discourse in anthropological systematics, American Journal of Physical Anthropology 94, no.11 (May 1994): 59–79.https://doi.org/10.1002/ajpa.1330940106Daniel Schmitt, Christine E. Wall, Pierre Lemelin Experimental Comparative Anatomy in Physical Anthropology: The Contributions of Dr. William L. Hylander to Studies of Skull Form and Function, (): 3–16.https://doi.org/10.1007/978-0-387-76585-3_1

Oxygen isotope composition of natural phosphates from volcanic ash soils of the Great Rift Valley of Africa and east Java, Indonesia

Volcanic ash soils of the Great Rift Valley of Africa and east Java, Indonesia, are highly fertile due to an ample supply of available phosphorus. The origin of the natural phosphates has been determined from oxygen isotope analyses ( δ 18O) which reflect the formation temperature of the PO bond. The δ 18O values of phosphates extracted from fourteen surface, or near-surface, soil samples ranges from + 10.1 to +24.8‰. The values are higher than those of recent volcanic ashes from Oldoinyo Lengai, Tanzania and Merapi, Indonesia ( δ 18O = + 5.3 to +6.2‰), and those of igneous apatites from carbonatites, geodes and hydrothermal deposits ( δ 18O = +0.2 to + 12.2‰, n = 10 ). The soils with δ 18O values at the lower end of the range are from Ngorongoro Crater Highlands and the footslope of Mt. Meru, northern Tanzania (+ 10.4 to +15.9‰) and east Java, Indonesia (+ 10.1 to +16.9‰), respectively, where the soil surfaces have both been rejuvenated by frequent deposition of volcanic phosphates in recent ashes. Higher δ 18O values (+ 16.7 to +24.8‰), which are comparable with those of wild mammal's skeletons ( δ 18O = +18.6 to +24.0‰), are observed for soils in advanced stages of pedogenesis. Oxygen isotope fractionation between phosphate and associated calcite has been evaluated for selected soil samples. The resulting isotopic temperatures are unreasonable, however, and indicate that the soil phosphates are not in isotopic equilibrium with the fluids responsible for authigenic calcite. Available phosphorus in the soils studied is derived from both of biogenic (plants and mammal bones) and volcanic sources.

Stable isotope labeling of lead compartments in rats with ultralow lead concentrations

The role of the mammalian skeleton as an endogenous lead source is unclear. This is due in part to difficulties in distinguishing mobilized skeletal lead from other endogenous and exogenous lead sources. Therefore, we have applied ultraclean stable lead isotope techniques to label skeletal and soft tissue lead compartments within the rat with distinguishable lead isotopic signatures. Female Wistar (defined flora) rats were fed 206Pb-enriched drinking water ([Pb] = 110 ng/ml) and sacrificed after durations of 2, 4, 7, and 14 days. Blood, kidney, vertebra, and tibia tissues were analyzed for lead concentrations and stable isotopic compositions. The resulting isotopic ratios in soft (blood and kidney) and skeletal (vertebrae and tibia) tissues differed by approximately 40% after 2 days exposure to the 206Pb tracer. More than 90% of the tracer isotopic signature was contained in the soft tissues after 10 days exposure, while skeletal tissues acquired only approximately 50% of the tracer by the end of the study. Because these animals were maintained under trace metal-clean conditions, they contained lead concentrations in whole blood (0.3-3 ng/g), kidney (11-27 ng/g dry wt), and bone (35-70 ng/g dry wt) tissues that are the lowest known reported for contemporary terrestrial mammals, and they (in bone) are comparable to levels in preindustrial mammals. The elevated concentrations of lead in kidney (fresh weight) relative to levels in blood are consistent with the presence of specific lead-binding sites in the kidney at very low levels of exposure.

Biomechanics of Mammalian Terrestrial Locomotion

Mammalian skeletons experience peak locomotor stresses (force per area) that are 25 to 50% of their failure strength, indicating a safety factor of between two and four. The mechanism by which animals achieve a constant safety factor varies depending on the size of the animal. Over much of their size (0.1 to 300 kilograms), larger mammals maintain uniform skeletal stress primarily by having a more upright posture, which decreases mass-specific muscle force by increasing muscle mechanical advantage. At greater sizes, increased skeletal allometry and decreased locomotor performance likely maintain stresses constant. At smaller sizes, skeletal stiffness may be more critical than strength. The decrease in mass-specific muscle force in mammals weighing 0.1 to 300 kilogram indicates that peak muscle stresses are also constant and correlates with a decrease in mass-specific energy cost of locomotion. The consistent pattern of locomotor stresses developed in long bones at different speeds and gaits within a species may have important implications for how bones adaptively remodel to changes in stress.

Climbing adaptations in the early eocene mammal Chriacus and the origin of artiodactyla.

A virtually complete articulated skeleton of the arctocyonid Chriacus, recently found in northern Wyoming, is one of the most intact early Eocene mammal skeletons ever found. It exhibits numerous adaptations characteristic of mammals that climb, including strong bony crests and processes (reflecting powerful musculature), ability for considerable forearm supination, a highly mobile ankle joint, plantigrade feet, curved and transversely compressed claws, and a long, possibly semiprehensile tail. These features contrast sharply with those of the oldest artiodactyls and indicate that Chriacus or a similar arctocyonid was not ancestral to the Artiodactyla, as has been proposed.

Exceptional preservation of Eocene vertebrates in the lake deposit of Grube Messel (West Germany)

Less than 2% of Lagerstätten with fossil vertebrate remains have yielded anything more than fragments of jaw material and other bones. One such exceptional deposit is the former oil shale mine of ‘Grube Messel’, located about 30 km south east of Frankfurt am Main. Articulated skeletons of various fish, salamanders, frogs, turtles, lizards, snakes, crocodiles, birds and mammals, as well as several hundred insects and plant remains, have been recovered, particularly during the last decade. The quality of preservation is truly exceptional. In many cases not only are the skeletons articulated, but the outlines of the entire body are preserved as black silhouettes. Sometimes even the contents of the digestive tract are available for investigation. Apart from the fish that formerly lived in the lake, the most frequent fossils found are flying creatures such as birds, bats and insects. Clearly, the lake acted as some kind of trap for these animals. The different modes of preservations are reviewed and the factors involved in this example of special preservation discussed.

A red deer (Cervus elaphus L.) skeleton from seamer carrs, Cleveland, England: Provenance of the skeleton and palaeoecology of the site

Abstract A Red deer, Cervus elaphus L., skeleton from Seamer Carrs was excavated and the collagen fraction of one of the bones dated to 4330 ± 100 bp (Birm. 977). The bones were embedded in a limnic sediment that was dated to 7360 ± 120bp(Birm.882). This date was confirmed by the pollen assemblage, which indicated a Flandrian I/II chronozone age. The date of the Cervus bone is explained by its movement vertically downwards in the limnic sediment. Attention is drawn to the number of large mammalian skeletons that have been recovered from Seamer Carrs during drainage operations and subsequently, and to the mesolithic and neolithic artifacts recovered from the slopes around the Carrs.

About Forty Last-Glacial Lake Missoula Jökulhlaups through Southern Washington

The rhythmic Touchet Beds in the Walla Walla and lower Yakima valleys resulted from many separate backfloodings by hydraulically ponded glacial Lake Missoula water. At least once this episodic lake briefly contained half the of water that catastrophically drained the largest glacial Lakes Missoula. Evidence that the Touchet Beds rhythmites originated from brief backfloodings includes up-valley thinning and fining of locally derived bedload, upvalley paleocurrents, and upvalley transport of erratics derived from Cordilleran ice. Evidence that a lengthy nonflood environment followed the emplacement of each of about 40 Touchet Beds rhythmite includes inferred eolian and slopewash sediment overlying many rhythmites, uncontaminated Mount St. Helens "set S" tephra couplet atop one rhythmite as much as 220 m below the maximum level of backflooding, filled semiconsolidated rodent burrows throughout the 30 m of the thickest section, and dispersed skeletons of mammals. The lack of weathering or soil within the Touchet Beds suggests that all rhythmites are late Wisconsin. Bottom sediment of glacial Lake Missoula in Montana consists of rhythmites each interpreted as the record of a gradually deepening lake. Forty superposed rhythmites record about 40 late-Wisconsin fillings and emptyings of glacial Lake Missoula. The complementary records of about 40 separate glacial Lakes Missoula and about 40 great floods in southern Washington and in the Willamette Valley, Oregon indicate that the Missoula floods were great jokulhlaups. The last several floods were smaller than earlier ones because the controlling dam of Cordilleran ice thinned during deglaciation.

The Use of Differentiation Staining of Bone on Anatomic Preparations

Cerveny C.: The Use of Differentiation Staining of Bone on Anatomic Preparations. Acta vet. Bmo, 48, 1979: 3-7. The method proposed for staining bone tissue on macroscopic anatomic prepara­ tions (Cerveny 1972) was tested and applied for investigations of topographic ana­ tomy, macrostructure of bones in ontogenesis, and for demonstration purposes.in lectures· on normal anatomy of mammalian skeletons. Attention was drawn to the possible use of this method for studies of the individual body regions. Using this method objective preparations can be gained of the bone macrostructure and whole topographic parts of the skeleton for lectures in normal mammalian anatomy. A se­ ries of preparations can be prepared giving the developmental changes of the struc­ ture of the skeleton, even in combination with roentgenography. Differential stain­ ing of bones can also be used for colour photographs. Bone, cattle, pigs, dogs, topographic sections.