Invertebrate Fossils Research Articles

Patterns of Change in Fossil Invertebrates

The problem with using fossils as evidence for evolution is that they are dead. You cannot experiment on them or watch them do anything. However, fossils more than make up for this shortcoming and provide compelling evidence for evolutionary change, because of their unique temporal dimension. Fossils give us information not just about the form of organisms, but also about their form through time. “Reading” this information from the fossil record, however, requires that we understand a central concept about how all science (and especially historical science) works, namely that processes produce patterns and, therefore, process can be reconstructed or inferred from those patterns. This is true even in the “hard” or “experimental” sciences. You do not have to see a process occur to have confidence that it did. When we look at the fossil record and ask, “How did it come to be this way?”, we answer by inferring continuity among the patterns resulting from a process of change that took place millions of years ago. We call that inferred process of continuity with change evolution.

Darwin and Cirripedia prior to 1846: Exploring the origins of the barnacle research

Phillip Sloan has thoroughly documented theimportance of Darwin's general invertebrateresearch program in the period from 1826 to1836 and demonstrated how it had an impact onhis conversion to transformism. AlthoughDarwin later spent eight years of his life(1846–1854) investigating barnacles, thisperiod has received less treatment in studiesof Darwin and the development of his thought. The most prominent question for the barnacleperiod that has been attended to is why Darwin``delayed'' in publishing his theory ofevolution. A related but distinct questionconcerns the variety of earlier events andinfluences that led Darwin to the study ofCirripedia in 1846, apart from its role in thetrajectory that led to On the Origin ofSpecies (1859). In this paper I focus on four specific episodesprior to 1846 that inform a picture of whyDarwin had an antecedent interest in barnacles:(1) the orientation to collecting strange andcurious invertebrate organisms, as well as thestrong affinities of Darwin's invertebratecollecting on the Beagle voyage with thework of John Vaughan Thompson; (2) the criticalrole of marine invertebrate fossils in Darwin'sgeological reasoning aboard the Beagleand exemplified in his GeologicalObservations of South America; (3) the strangeabsence of a Zoology of the Beagle volumeon invertebrates and Darwin's original intentto publish some of the descriptions himself;and (4) the noteworthy presence of barnacles inDarwin's transformation theorizing between 1837and 1839. There is a wealth of support for thethesis that Darwin had a strong interest incirripedes prior to the formal barnacleresearch, blunting arguments that it was psychologicalaversion or a feeling of inferiority about histaxonomic abilities that drove Darwin to thecirripedes.

Invertebrate fossil assemblage from Galisteo Dam and the correlation of the Cretaceous Dakota-Mancos succession in north-central New Mexico

Invertebrate fossil assemblage from Galisteo Dam and the correlation of the Cretaceous Dakota-Mancos succession in north-central New Mexico

Geochemical and physical characteristics of river and lake sediments at Naivasha, Kenya

Prior studies on Lake Naivasha relevant to understanding sediment dynamics include a bathymetric map, a paleolimnological study of fossil invertebrate assemblages in lake sediment, an overview of lake level fluctuations throughout the 20th century, and identification of a dynamic assemblage of macrophyte zones that has responded both to these changes in lake level and to more recent, alien species. Sediment samples collected from the rivers systems and the lake were examined physically and chemically. River sediment characteristics reflect geology and geomorphological processes in the catchment, whereas lake sediment stratigraphy has responded to past lake level changes. Such changes have caused significant changes in aquatic vegetation assemblages. Present day sediment dynamics in the lake are governed by the presence of river point sources in the north and wave-induced re-suspension, such that sediments introduced by rivers are transported in easterly and southerly directions, and are eventually deposited in the eastern, central and southern parts of the lake. Sedimentary deposition is also occurring in northern areas that once were protected by papyrus swamp vegetation but now only have a narrow fringe, highlighting the important role of swamp vegetation in filtering out suspended particulates and thereby controlling water quality in the lake. Geochemical analyses of river and lake sediments indicate that they represent fairly undisturbed background conditions. Higher-than-expected concentrations of cadmium, iron, nickel and zinc found in both river and lake sediment are likely to derive from volcanic rocks and/or lateritic soils found in the lake catchment.

The Kathmandu Basin: an archive of Himalayan uplift and past monsoon climate

The basin-fill sediment of the Kathmandu Valley is one of the best archives of both Himalayan uplift and past monsoon climate. Thick lacustrine sediments, mainly comprised of black clay, locally called as Kalimati clay, are the deposits of the Paleo-Kathmandu Lake during the last 2.5 million years, and the underlying fluvial sediments represent the deposits by the Proto-Bagmati River of the valley. The clay-predominant Kalimati Formation is rich in proxies of paleoclimate, such as fossil pollen and diatom as well as vertebrate and invertebrate fossils. In addition, crystallinity, chemical composition and stable isotope of clay minerals have a potential to provide a continuous paleoclimatic and paleoenvironmental records in the Central Himalaya. The sedimentological study of the fluvial and deltaic deposits that rest on the Kalimati Formation would reveal recent changes of tectonic and depositional environments in the Central Himalaya.

Book Review - Atlas of early Palaeogene Invertebrate fossils of the Himalayan Foothills Belt

Book Review - Atlas of early Palaeogene Invertebrate fossils of the Himalayan Foothills Belt

Mixing of CO2 in surficial environments as recorded by the concentration and δ13C values of the Fe(CO3)OH component in goethite

Measured values of mol fraction (X) and δ13C in the Fe(CO3)OH component of 49 samples of goethite (α-FeOOH) from a wide variety of environments range from 0.0015 to 0.0182 and from −21.7 to +3.3‰, respectively. The distribution of δ13C values appears to be bimodal. δ13C values are > −12‰ for marine hydrothermal goethites and continental goethites crystallized as secondary minerals in host rocks. With the exception of a young soil (DRR), δ13C is < −14‰ for pedogenic/oolitic and bog ore goethites.Values of X and temperature determined for pedogenic goethite can be combined with the modern, global relation between soil respiration (Q) and average annual temperature to estimate diffusion coefficients (DS) for steady-state Fickian diffusion of CO2 in soils. Although there is considerable scatter in the relationship between Q and T, an illustrative calculation for a characteristic depth of 0.20 m, yields calculated values of DS that range from about 0.002 to 0.011 cm2/s among seven goethite-bearing soils.Steady-state diffusive transport of CO2 in soils with one in situ source of CO2 (oxidation of organic matter) yields a soil CO2 mixing equation for two isotopically distinct CO2 components (oxidized organic matter and atmospheric CO2). With pedogenic goethite as a proxy for the soil CO2, the positive slope of this two-component mixing equation can be used for determinations of CO2 pressures in the Earth’s atmosphere. If, however, dissolution of carbonates is concurrent with goethite crystallization, the mixing equation (at z ≫ z∗) becomes three-component with a negative slope that precludes estimates of atmospheric Pco2. An example is the DRR soil in which in situ, low-pH dissolution of relict, marine invertebrate fossils produced a negative mixing slope and goethite δ13C values that range from −14.2 to −4.1‰. These results indicate that only goethites which crystallized in carbonate-free soils (highly leached or formed on initially carbonate-poor rocks) should be used to deduce ancient atmospheric CO2 pressures.Addition of CO2 from dissolution of carbonates also appears to explain the range of δ13C values of most of the secondary continental goethites presumably formed in saturated groundwater systems. However, some of the variation of X and δ13C of the Fe(CO3)OH component in these goethites may be a consequence of variations in ambient pH. This possible dependence on pH seems to be manifested in a suite of goethites pseudomorphed after pyrite in a marine limestone.

Continental island from the Upper Silurian (Ludlow) Sino-Korean plate

Recent field studies on Upper Silurian stratigraphy and paleontology in the Inner Mongolia Autonomous Region (for short Inner Mongalia) near Bater Obo (=Bateaobao) resulted in the discovery of a small continental island with fossil invertebrates preserved as encrusters (stromatoporoids and corals) attached directly to a rocky shore surface and buried by silty clay mud. The Bater island (oamed herein) is 610 m × 200 m in size and composed of Ordovician igneous rock (diorite). Limestone strata dating from the Ludlow Epoch (about 420 Ma) surround the island and dip away from the igneous core in a radial pattern. The encrusting fossils occur on the sheltered (south and southeast) side of the island, whereas the north side was exposed to stronger wave activity based on a basal conglomerate unit composed of diorite boulders. This is the first record of an ancient island in China and the first report worldwide of stromatoporoids as members of a rocky-shore community. The island clearly shows distinct windward and leeward deposits comparable to geologically younger islands from the Mesozoic and Cenozoic outside China.

Late Jurassic invertebrate fossils from the Little Hatchet Mountains, southwestern New Mexico

Late Jurassic invertebrate fossils from the Little Hatchet Mountains, southwestern New Mexico

Evidence of glacial abrasion in the Calingasta–Uspallata and western Paganzo basins, mid-Carboniferous of western Argentina

Evidence of glacial abrasion is present in the basal part of the Carboniferous section of the Calingasta–Uspallata and Paganzo (western Argentina), where subglacial and proximal glacial-marine diamictites with pebbly (dropstone) shales constitute the dominant facies association. Intraformational striated pavements are exposed in the Hoyada Verde and Leoncito Formations of the Calingasta–Uspallata basin. Marine invertebrate fossils ( Levispustula zone) in associated shales indicate a mid-Carboniferous age for both units. A single layer striated boulder pavement is superbly exposed in the Hoyada Verde Formation. Local a-axis clast imbrication in the underlying bouldery diamictite and strong parallel striae on the flattened upper surfaces of boulders indicate a subglacial origin for the pavement. Paleo-ice flow directions have an NNE–SSW strike. The Leoncito intraformational pavement is shaped on bioturbated, fine-grained sandstones with plant remains. Glacial striations are straight and parallel with subcircular cross-sections. Dome-like features are present in the surface, which is covered in turn by a sandy bouldery diamictite. Four striated surfaces are present in the western Paganzo basin. Three of them (pavements at the San Juan river valley, Loma de Los Piojos and Agua Hedionda) are developed on basement rocks. They contain parallel to subparallel striations, nailhead striations, crescentic gouges, impact marks and furrows. The pavements are overlain by thin (up to 1.5 m), laterally discontinuous diamictite beds with striated clasts, some of them bullet-shaped. Paleo-ice flow directions are N–NE-directed. An intraformational pavement is also present at the San Juan river valley section; it is carved on the top of the basal diamictite and exhibits furrows, probably caused by subglacial soft-sediment grooving. The dispersion of paleo-ice flow directions in the Calingasta–Uspallata and Paganzo basins indicates: (i) regional slopes toward the north into a brackish water embayment and northwest into the open marine conditions; (ii) glacial erosion by ice grounded below sea level and confined to the margins of the basins.

Occurrence of Plio-Pleistocene phosphatized macro-invertebrates from the upper west Florida slope, eastern Gulf of Mexico

Numerous phosphatized internal molds of an articulate brachiopod, along with fossils from four other phyla (Cnidaria, Mollusca, Annelida, and Echinodermata), were collected from several dredge sites in the Gulf of Mexico. The samples were collected during two cruises aboard the RV Suncoaster in December 1989 and May 1993, approximately 250 km west-southwest of Tampa, Florida. These cruises were not designed to collect fossils, rather they were aimed at studying the origin of phosphorite nodules and hardgrounds developing in response to marginal upwelling of the Gulf of Mexico Loop Current along the western margin of Florida. The invertebrate fossils were collected as part of the phosphorite nodule dredge hauls and are the focus of this study. Mineralogical analysis of these internal molds, including a brachiopod and the largest of the three echinoid specimens, indicates they are composed of francolite, low-magnesium (Mg) calcite, aragonite, and variable amounts of quartz, which is consistent with nonferruginous nodules recovered from the same areas. Petrographic examination also identified glaucony and iron-oxyhydroxides (FeOOH) within the phosphatic molds. The timing of phosphogenesis associated with the fossils and nonferruginous nodules has been identified as occurring after a late Miocene (Tortonian) sea level lowstand, most likely during Plio-Pleistocene sea level highstands that favored marginal upwelling over the west Florida slope. We interpret the paleoecology of the fauna to represent a continental shelf environment of shallower depth than where the fossits were collected (511-520 m) along the west Florida slope. Though all the taxa have ranges of depth from which they have been recorded, the best synthesis using all the fossils indicates an environment of less than several hundred meters depth. It is likely that some transportation of the organisms occurred after death. Also, significant exposure effects (such as encrusting organisms and borings) are present on the fossils. Therefore, some mixing of the shallower water and deeper water fauna possibly occurred prior to their ultimate inclusion within the limestone outcrops on the west Florida slope.

Fossil Invertebrate and Microfossil Collections: Kinds, Uses, Users

INVERTEBRATE and micro-fossil collections vary in size, scope, degree of documentation, quality of curation, purpose, usage, and security. This chapter introduces the main categories of fossil collections and curatorial attention, and documents the sources and uses of invertebrate paleontological materials. The term ‘permanent collection’ is used to describe collections housed in professional collections-care institutions that provide long-term commitment to collection security and curation. Invertebrate fossils include the hardparts (spicules, shells, etc., other body fossils [e.g., impressions, casts, and molds]), tracks, trails, and burrows attributed to invertebrates, and organic molecules. Microfossils, included here for convenience only, include the same kinds of remains of prokaryotes, protists, and tiny invertebrates. This book is the product of an National Science Foundation funded workshop organized to address specific concerns about curatorial practices in invertebrate paleontology. For this reason the focus of this chapter is on invertebrate fossils. Nevertheless, the concepts and uses of collections described below apply directly to paleobotanic specimens, and to most vertebrate fossils.

The Scientific Value of Natural History Museum Collections: The Concept of Completeness

NATURAL HISTORY MUSEUMS are one of the greatest resources available to paleontologists and evolutionary biologists. Through their exhibits, they have inspired generations of children to become paleontologists, and they also serve as a tremendous repository of realized and potential data. If invertebrate fossils can be thought of as individual data points, in the United States alone there are perhaps 100 million data points. Yet, in spite of this, museums, like other sources of data, have their shortcomings. What are these short comings, and how severe are they? Are they so severe as to obviate the scientific value of the collections of fossils held by natural history museums? It is this topic that we address herein.There is a useful analogy between the debate about the usefulness of natural history museum collections and the debate about the completeness of the fossil record. Are natural history museums representative of the fossil record, and are they complete enough to be adequate for research? We intend to pursue the analogy between the fossil record and natural history museums as we develop our ideas about paleontological collections. Just as numerous studies have concluded that the fossil record, albeit incomplete, is adequate to answer a wide variety of scientific questions, so too shall we argue that the data preserved in natural history museums are complete enough and adequate to answer a wide variety of important research questions in paleontology.

Evidence for short-lived oscillations in the biological records from the sediments of Lago Albano (Central Italy) spanning the period ca. 28 to 17 k yr BP

We report the results of analyses of pigments (derived from algae and photosynthetic bacteria), diatoms and invertebrate fossil remains (ostracods, cladocerans, chironomids) in two late Pleistocene sediment cores from Lago Albano, a crater lake in Central Italy. The record contains evidence for oscillations in lake biota throughout the period ca. 28 to 17 k yr BP. The earliest of these are contained in the basal 3.5 m of light olive-gray and yellowish-gray spotted muds sampled in core PALB 94-1E from 70 m water depth. The later oscillations are best represented in the more extended sediment sequence recovered from a second core site, PALB 94-6B, in 30 m water depth. The sediments at site 1E, containing the earlier oscillations (ca. 28-24 k yr BP), predate any sedimentation at the shallower site, from which we infer an initially low lake level rising to permit sediment accumulation at site 6B from ca. 24 k yr onwards. At site 6B, massive silts rich in moss remains are interbedded with laminated silts and carbonates. These sediments span the period ca. 24 to 17 k yr and are interpreted as representing, respectively, times of shallow water alternating with higher lake stands, when the lake was stratified and bottom water was stagnant. A range of mutually independent chronological constraints on the frequency and duration of the oscillations recorded in the lake biota indicate that they were aperiodic and occurred on millennial to century timescales. We interpret them as responses to climate forcing through its impact on lake levels and changing aquatic productivity. The time span they occupy, their frequency and their duration suggest that at least some of these changes may parallel both the Dansgaard-Oeschger events recorded in Greenland Ice Cores and the contemporary oscillations in North Atlantic circulation documented in marine sediment cores.

Guidelines for the Documentation and Care of Invertebrate Fossil Collections

COLLECTIONS OF invertebrate fossils are commonly maintained in museums, at universities, and by individual researchers and interested private collectors. Twenty years ago, the Committee on North American Resources in Invertebrate Paleontology (CONARIP) estimated that there more than 550 institutions housed invertebrate paleontological macro- and micro- fossil collections (Glenister, 1977). Historically, collections have been developed, managed and maintained by paleontologists as a resource for their research (e.g., museum curator or university faculty) (Hebda, 1985). Since the early 1970s, the field of collection management has evolved and the increased professionalization of collection manager positions has been instrumental in improving the management and preservation of invertebrate fossils as well as other natural history collections (Cato, 1991; Simmons, 1993; Simmons, 1995).

Balancing Resources and Collections Needs: I. Acquisition and Accession of Invertebrate Fossils

ALL MUSEUMS have limited resources, and all acquisitions use some of these resources, whether they be space, money, staff time or materials. When museums purchase collections objects, some “costs” are evident up front, and there are frequently mechanisms in place at a high level to monitor that use of museum resources. For example, in art museums this is often a committee of the board of directors empowered to approve or deny curatorial proposals for major (i.e., expensive) acquisitions. However when the object is “free,” as in most invertebrate paleontology collections where material is either donated or collected in the field by museum staff, the cost of acquiring the object is essentially hidden. Some acquisition costs may be fixed regardless of the size or nature of the acquisition, and some vary depending the amount of space the material will require, or the amount of cleaning or conservation needed.

Institutional and Individual Orphaned Collections

“ORPHAN” IS AN incongruous word to apply to something dead for millions of years. But there is no better term to describe the state of an invertebrate paleontology collection whose guardian can no longer care for it. The numbers of specimens in invertebrate fossil collections do not set them apart from other natural history collections; however, add weight and volume, and it is obvious why adopting these orphans pose special problems. The workshop coordinators divided the discussion of orphaned collections into those held by industry and governmental agencies (see Allmon, Chapter 4, this volume) and those housed by institutions and individuals addressed here. Topics discussed at this session of the workshop included: the definitions of orphaned and endangered collections, why collections become orphans, which collections are most vulnerable, and what, if anything, can be done to prevent orphaned collections in the future. I have attempted to present an objective report of the discussions and proposed suggestions, but my bias as curator of a collection housed within an academic department may have crept in.

Appendix III: Survey of Endangered and Orphaned Invertebrate Fossil Collections

Appendix III: Survey of Endangered and Orphaned Invertebrate Fossil Collections

Balancing Resources and Collections Needs: II. Deaccessioning and Disposal of Fossil Invertebrates and Microfossils

AS RECENTLY as thirty years ago, deaccessioning was a dirty word in museums. It was considered an abrogation of an institution's fundamental responsibility to care of its collections in the public trust. Miller (1985) has chronicled some of the public controversy that attended deaccessioning in the early 1970's. However, in the intervening time, museums' approach to deaccessioning has changed as they grapple with burgeoning collections, decreasing funding bases, pressure to narrow and focus their missions, and rising standards of care. Now deaccessioning is regarded by the majority as a necessary and appropriate tool in collections management, albeit one that operates within strict ethical and legal constraints.A museum's collections policy should address criteria for deaccessioning, levels of approval needed, methods of disposition, use of funds resulting from sales, and records keeping. In addition, staff must develop procedures for identifying material for deaccessioning. In the following sections we review the currently accepted standards in the museum field for these areas, as well as discussing how some of these issues apply particularly to paleontological collections. It may be appropriate for paleontology departments to develop guidelines and procedures that further refine the museum's overall collections policy to fit the needs of their collections and the conventions of their field.

The temptations of evolutionary ethics

Journal of the History of the Behavioral SciencesVolume 36, Issue 3 p. 294-295 Book Review The temptations of evolutionary ethics Matthew H. Nitecki, Matthew H. Nitecki Curator Emeritus of Fossil Invertebrates Field Museum of Natural History, Chicago IL 60605Search for more papers by this author Matthew H. Nitecki, Matthew H. Nitecki Curator Emeritus of Fossil Invertebrates Field Museum of Natural History, Chicago IL 60605Search for more papers by this author First published: 12 July 2000 https://doi.org/10.1002/1520-6696(200022)36:3<294::AID-JHBS24>3.0.CO;2-6AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume36, Issue3Summer 2000Pages 294-295 RelatedInformation