Single data sets, whether derived from morphological or molecular evidence, provide one-off estimates of the correct phylogeny. Their reliability can only be gauged by statistical approaches such as bootstrapping or clade decay, but these test only whether there are sufficient characters in the data matrix to justify the groupings identified. They do not test whether the characters themselves are reliable. Consequently, confidence in the correctness of phylogenetic interpretations comes primarily from discovering the same (or statistically indistinguishable) patterns from independent data sets.

Congruence studies are most advanced for echinoids, where four independent data sets (two morphological and two molecular) provide strong corroboration for a single phylogenetic scheme. Analysis of all four data sets combined generates a highly robust hypothesis of relationships. The situation is very different for asteroids. Two analyses based on morphological data have reached very different conclusions. Three independent molecular data sets also have been compiled, but none has a statistically reliable signal concerning higher taxon relationships. Even combining all three molecular data sets fails to generate a statistically robust solution, implying that the major lines of asteroids diverged rapidly from one another. For ophiuroids, both morphological and molecular data generate topologies that for the most part lack statistical robustness. There is currently no cladistic analysis of holothurian relationships based on morphological data, and only a few taxa have been sequenced. The molecular data is, however, congruent and does permit an initial assessment of relationships. Nothing definite can be deduced about crinoid relationships since even fewer molecular sequences are known and morphological analysis remains sketchy.

Class-level relationships derived from two morphological and two molecular data sets also show considerable congruence, though a single definitive solution has yet to emerge.

Organic carbon compounds record key aspects of the processes of their formation and mechanisms of preservation and are foci for research into the nature of life on the early Earth and the search for life beyond Earth. Prime in this respect are lipids preserved in sediments and sedimentary rocks that reveal much about the evolutionary trajectory of life on our planet. Lipids, predominantly derived from photoautotrophic microbes, dominate hydrocarbon records in the Precambrian. The rise to prominence of the Metazoa in the late Neoproterozoic, metaphytes in the Paleozoic, and modern plankton in the Mesozoic, can also be seen in the occurrences of distinctive molecular fossils. Organic matter of all types is optimally preserved in environments and sediments where radiation (solar and ionizing) and oxygen are excluded. In the marine realm, anoxic water bodies will often become sulfidic (euxinic) due to the activity of sulfate-reducing bacteria. Phototropic sulfur bacteria thrive in such environments, and the presence of their characteristic carotenoid pigments goes hand-in-hand with the enhanced preservation of all organic matter, driven by the reducing power of sulfide. The deleterious effects of radiation and oxygen on the preservation of organic matter are amply demonstrated by the results of ongoing searches for carbon compounds on the surface of Mars. The production of highly oxidizing substances through radical chemistry operating in the Martian atmosphere has resulted in environmental conditions that virtually assure destruction of much of the organic matter produced in situ or carried there on meteorites and interplanetary dust particles.

Little good and a lot of bad come from reef restoration. Reefs damaged by humans and nature are “restored” using unnatural materials as substrata quickly occupied by corals and fish. This is commonly considered good, for seemingly the reef has been returned to a “healthy” state; fish can be caught again and tourists return for the “beautiful reefs”. Restoration, the act of reestablishing a former state, has never been accomplished on a reef; rather reefs have been manipulated to conform to particular human values without regard for the entire reef—its ecology, trophodynamics, hydrodyamics, physical or chemical characteristics of pseudo-substrata, geochemistry, nutrient supply, and even reef aesthetics among a multitude of others. People seemingly cannot leave well enough alone when it comes to reefs that have been noticeably damaged. Yet, that is exactly what reefs need—time without interference. Careful analysis of the total consequences of various methods is required. Reefs evolved over millions of years in one of the harshest environments on earth—the air-water interface. They are well adapted to recover from physical damage of almost any sort. Reefs are not fragile. Thoughtful assistance would help, using materials occurring naturally within reef systems, by involving regional stakeholders in natural processes of restoration, and by stringent protection regulations and agreements. Opportunistic “restoration” by well-meaning, misguided or avaricious people without careful consideration of what really constitutes a reef is a major mistake that will eventually degrade reefs and need restoration itself. Protection of reefs is the best option, followed by letting natural restorative processes take place over long times.

The Brachiopod shell provides more than protection for the organism dwelling within: it provides a structural record of growth and a chemical record of fluctuations in the environment in which it formed. Typically, a shell formed by an accretionary process will have growth lines visible on the shell surface that can be used to measure chronological age directly. This is common in many fossil and modern bivalve molluscs where growth bands are prominent (see, e.g., Lutz and Rhoads, 1980; Jones, 1983; Tanabe, 1988). However, growth increments are not always so easily identified in other shelled organisms. For instance, growth lines in brachiopod shells are often indistinct, and the time interval represented by each growth line is uncertain. When growth information can't be obtained directly, we must turn to an alternative method (Jones and Gould, 1999). Fortunately, periodicities in the chemical composition of a shell may serve as proxies for age (e.g., Buening and Carlson, 1992). The shell chemistry of brachiopods reflects, for the most part, the changes in chemistry of the surrounding seawater. For instance, partitioning of oxygen isotopes (18O/16O ratio) in shell carbonate is sensitive to temperature (e.g., Hoefs, 1997). Thus, if brachiopods precipitate shells in water that is affected by seasonal temperature variations, then fluctuations of the 18O/16O ratio of the shell should provide a record of annual temperature variation in ambient seawater. Consequently, this seasonal record may be used in conjunction with structural growth lines to reconstruct the life history of the individual, as well as the local environmental conditions in which the brachiopod lived.

The Wenlockian lichid trilobite Arctinurus boltoni has been regarded as a classic example of a “snow-shoe” type adaptation. That is, the broad flat doublure has been interpreted as a resting surface, with well-developed terrace ridges serving as either sensory or frictional devices. New data from the Rochester Shale of western New York State indicate that this interpretation is incorrect The discovery of the small, calcareous worm tube Cornulites on complete, articulated specimens of Arctinurus indicates that these trilobites seldom rested their doublure on the sediment surface. Apertures of all specimens of Cornulites are oriented posteriorly, suggesting a rheophilic response to persistent water circulation patterns beneath the trilobite. The presence of suspension feeding organisms on the doublure also indicates that the water currents beneath the trilobite were free of suspended mud, so that Arctinurus may not have processed sediment in search of food.

Large specimens of Arctinurus also have numerous epibionts on the dorsal shield, including cyclostome bryozoans, brachiopods (Stegerhynchus) and Cornulites. The presence of these suspension feeders indicates that Arctinurus did not burrow or even partially cover itself with mud. The large number of epibionts on adult specimens of Arctinurus, including several age classes for Stegerhynchus, indicates that molting stopped or at least slowed greatly once a certain size was attained, and that these trilobites may have had fairly long life spans.

Trilobites are the most diverse of extinct arthropod groups, being known from several thousand genera; many more are discovered each year. They range in age from near the base of the shell-bearing Cambrian to high in the Permian. Because many trilobites evolved quickly, they have been widely employed in stratigraphy; in the Cambrian they are possibly the most important stratigraphical fossils. This has been a mixed blessing because some experts studying the group have tended to place stratigraphical utility foremost in their taxonomic methods. Stratigraphical boundaries have become taxonomic boundaries. This might not matter for stratigraphy, but it does matter for the other kinds of paleobiological studies which have recently become the center of attention. How, for example, can one study extinction, unless the groups extinguished are natural, monophyletic groups? The extinction of an arbitrary phylogenetic segment at a stratigraphic boundary tells us nothing.

The last two decades have seen the status of deposits containing soft bodied Cambrian fossils rise from geological curios into one of the foundations of modern thinking on early metazoan evolution and ecology. Some thirty of these soft bodied assemblages or Lagerstätten, resembling the Burgess Shale fauna are now known. One of these is the Lower Cambrian Emu Bay Shale fauna from Kangaroo Island, South Australia.

The Emu Bay Shale has been mapped in two localities approx. 8 km (5 miles) apart on the northern coast of Kangaroo Island, at Emu Bay and at Big Gully. Previous investigations into the numerically abundant Lagerstätten fauna at Big Gully have highlighted its unusually pauperate diversity, with only some seven species described. The preservation is also unusual, comprising replacement by iron stained calcite. The fauna is confined to a 10 m thick basal siltstone. The age of the deposit is believed to be mid to upper Botomian and is thus marginally older than Early Cambrian soft bodied assemblages found on the North American continent and predating the better known Middle Cambrian Burgess Shale.

In late 1991, a study of the Emu Bay Shale was undertaken to document the palaeontology and palaeoecology of the fauna. Preliminary findings, whilst increasing the number of species, confirm the pauperate diversity of the fauna. The new forms include several specimens of anomalocarid appendages. These not only represent the first occurrence of this form in Australia, but also the first occurrence outside the Burgess Shale of anomalocarid appendages with 11 segments, as compared with the more common and widespread 14 segment appendages. This connection may be important in the light of recent palaeoreconstructions which show the west coast of Canada and eastern Australia in close proximity during the early Cambrian. Also the spatial arrangement of the appendages indicates that anomalocarids may have shoaled and hunted in groups. They appear to have fed on the sea bottom, possibly using their appendages to probe the muddy bottom for shallowly buried prey as well as for capturing and transporting prey to the mouth.

The assemblage appears to be dominated by the preservation of hard or permineralized body parts. However, abundant calcified ribbon-like structures concentrated on some bedding planes have yet to be classified. Several exceptionally preserved specimens of Myoscolex appear to have a series of metamerically repeated ‘paddle-like’ appendages, similar to some forms from the Burgess Shale, thus casting doubt on an annelid affinity.

The assemblage appears representative of a deep water, low oxygen environment prone to periodic anoxia, possibly similar to the accretionary environment of the Burgess Shale.

The Emu Bay Shale at Emu Bay exhibits a shelly assemblage, mostly comprised of disarticulated Hsuaspis exuvia with occasional small Redlichia exuvia and hyolithids. No calcite replacement is evident. The location represents current swept, probably shallow water environment.

Climatic effects on aquatic environments are an important factor in the ecology of ostracodes judging from their biogeography especially with respect to moisture balance and ecoregions (vegetation zones). The importance of climate in controlling ostracode distribution is underscored by major ecological changes indicated by co-stratigraphic changes in ostracode and pollen biozones throughout the Quaternary. Climatic interpretation of ostracode records are complicated, however, by several non-climatic factors, including basin shoaling, changes in water chemistry due to abrupt changes in the flux of groundwater, rivers, and streams to lakes and wetlands, and increasingly shortened water residence time in areas where precipitation exceeds evaporation due to erosion by basin overflow.

Laser and structured light scanners are primary tools for acquiring surface details of body and trace fossils and have been widely used to study vertebrate specimens. Comparison of different scanner types shows their relative advantages and limitations. Regardless of scanning device, the workflow from initial scan to final product involves registration and some editing for archival or research-grade products. Additional steps, including further object editing and optimization, are required to prepare a scan file for web viewing, animation, and three-dimensional (3-D) printing.

New, competing ideas on crinoid plate circlet homologies and the desire for a phylogenetically-based classification have led to a reexamination of the Crinoidea. The most primitive crinoids had four plate circlets, from bottom to top: lintels, infrabasals, basals, and radials. Dicyclic camerates, cladids, flexibles, and dicyclic articulates are composed of infrabasals, basals, and radials. Monocyclic camerates and monocyclic articulates are composed of basals and radials. These all follow traditional ideas on homologies. In contrast, disparids with “compound radials” are composed of lintels, infrabasals, and radials, rather than “basals,” “inferradials,” and “superradials;” and disparids without “compound radials” have lintels and infrabasals rather than “basals” and “radials.”

Parsimony-based phylogenetic interpretation of Ordovician crinoids with rhombiferans as the outgroup shows that crinoids are divisible into six clades, two paraphyletic and four monophyletic, including four-circlet crinoids, cladids, disparids, camerates, flexibles, and articulates.

Museum exhibitions possess a long history of serving as useful tools for teaching both paleontology and evolutionary biology to college undergraduates. Yet, they are frequently under-appreciated and underutilized. However, they remain potentially outstanding resources because they can be used to meet a spectrum of learning objectives related to nature of science, real-world relevance, and student interest. Specifically, even small museum displays can provide: 1) authentic specimens, which often are more diverse, of higher quality, and historically more significant than those in teaching collections; 2) specimens in context, with other specimens and/or geological or biological background available; 3) examples of how fossils connect to virtually all of Earth and life sciences (explaining why they have so frequently been at the center of traditional “natural history”); 4) cross-disciplinary experiences, connecting science, art, technology, and history within a social context; and 5) opportunities for students to learn about teaching. A survey of instructor-developed activities performed within a host of natural history museums—with particular attention devoted to the Museum of the Earth, an affiliate of Cornell University—suggests that natural history exhibitions, regardless of size and scope, can complement and strengthen formal education in an undergraduate setting.

Freezing and thawing is accelerated mechanical weathering. We have little firsthand experience with this technique, but it has been written about in English by several authors who have used water, or water with a dissolved sodium salt (Hanna and Church, 1928; Sohn, 1959, 1961; Sohn, Berdan, and Peck, 1965; and Surlyk, 1972).

Isotopic biogeochemistry (13C, 15N) of fossil collagen is nowadays currently used to infer extinct animals and prehistoric man diet, and a wide developement of this technic is expected in the near future. In prehistoric specimens, only parts of bones and teeth are usually available and we have to be sure that isotopic values from any part of a single skeleton do not differ significantly before comparing isotopic values from different specimens.

Isotopic investigations on recent lower jaws from several mammal species show that δ13C values do not differ significantly between bone and teeth collagen but that δ15N values present an enrichment (up to 2–3 ±) in teeth collagen compared to bone in species with teeth that stop growing (reindeer Rangifer tarandus, sheep Ovis aries, bear Ursus americanus, wolf Canis lupus). On the contrary, species with continuously growing teeth (horse Equus caballus) present almost identical δ13C and δ15N values in bone and teeth collagen. Such δ15N values variations are very probably linked to teeth replacement chronology and time of weaning in the different species and for each tooth. Species with continuously growing teeth show similar evolution of isotopic variations in teeth and bone collagen during their lifetime.

Quaternary mammals almost 45 000 years old from France present a similar variation pattern for isotopic values in bone and teeth collagen. Cave bears (Ursus spelaeus) from Aldene and Mialet caves present slightly more negative δ13C values (-0.3 to -1.1 ±) and significantly more positive δ15N values (1.5 to 2.2 ±) in teeth than bone collagen from same fossil individuals. On the site as a whole, collagen δ13C values for definitive teeth are on average 0.7 and 1.1 ± more negative than for bone and δ15N values for definitive teeth are on average 3.1 and 1.9 ± heavier than for bone in Aldene and Mialet caves respectively. In Aldene cave, collagen δ13C values for deciduous teeth are on average 1.5 ± more negative than for bone and collagen δ15N values for deciduous teeth are on average 4.4 ± heavier than for bone. In Marillac, reindeers (Rangifer tarandus) present collagen δ13C values for definitive teeth almost identical than for bone and collagen δ15N values for definitive teeth are on average 1.8 ± heavier than for bone. On the contrary, there is no significant difference between δ13C and δ15N values from horses (Equus caballus) bone and teeth collagen, for a single individual as well as on average of several specimens.

δ13C and δ15N values seem to be equivalent between teeth and bone collagen only for species where teeth grow continously during the whole lifetime. In species where teeth stop growing in adult life, teeth collagen δ15N values seem to be significatly enriched in comparison with bone collagen δ15N values (1 to 3 ±), probably because of an 15N-enriched diet (milk) during the first stages of growing and no subsequent renewal of teeth collagen. The enrichment seems to be even more important for deciduous teeth.

Further investigations on recent mammals teeth and bones are thus urged to obtain a more accurate estimate of intra-individual isotopic variations according to individual age in the most studied species, including man.

Preservational style of fossil echinoid tests allows assessment of the likelihood of post-mortem transport out of the preferred sediment type of the living echinoid. Sedimentologic study of the matrix of untransported specimens allows a check on functional morphologic inferences of the species' preferred sediment types. Functional morphologic analysis allows inference of a species preferred sediment type because the petals, fasciolaes, tubercles, ambulacral pores, ambulacral shape, and test profile control the echinoid's ability to burrow, and the grain size of sediment into which it is capable of doing so. Past studies have achieved better than 90% accuracy in predicting the grain size of thin sections of rocks containing echinoids, simply by interpretation of their functional morphology. Most mistaken predictions are attributable to species living in sediments that are less difficult to burrow in (sands) than those to which they are adapted (muds). Other species may live in sediments in which they are not well adapted by assuming an epifaunal mode of life.

Relative proportions of species in an echinoid fauna preferring various sediment grain sizes, plotted for each of a number of localities, has proven useful in inferring generalized facies patterns within regions.

Plots of temporal changes in echinoid species diversity through time correspond well to changes in proportions of species inferred to have preferred various substrate conditions, suggesting an environmental and taphonomic component to simple diversity curves.

Ultrasonic cleaning is a fast and usually safe method for cleaning many hard objects that are not glued together, and it is thus useful in paleontological laboratories. It is relatively ineffective for cleaning soft materials such as rubber, cloth, and fibers. Ultrasonic cleaning machines use sound waves, or mechanical vibrations, that are above the human hearing range, and operate at frequences up to 55,000 cycles per second. The sound waves are generated by a transducer (Figure 1), which changes high frequency electrical energy to mechanical energy. This mechanical energy, or vibration, is then coupled into the liquid in the cleaning tank. The vibrations cause alternating high and low pressure waves in the liquid. This action forms millions of microscopic bubbles, which expand during low pressure waves and form small cavities. During the high pressure waves, these cavities collapse, or implode, creating a mechanical scrubbinglike action, which loosens dirt on all surfaces in contact with the cleaning solution. This action can take place up to 55,000 times a second, making it seem as though the dirt is being blasted from the surface and cavities of the object being cleaned. Ultrasonic cleaning is effective wherever capillary action will take the solution. Complete cleaning usually requires from 30 seconds to two minutes (Anonymous, 1983).