Diversity partitioning of a Late Ordovician marine biotic invasion: controls on diversity in regional ecosystems

Paleobiology ◽  
2007 ◽  
Vol 33 (2) ◽  
pp. 295-309 ◽  
Author(s):  
Mark E. Patzkowsky ◽  
Steven M. Holland
Keyword(s):  
Fossil Record ◽  
Resource Limitation ◽  
Late Ordovician ◽  
Ecosystem Change ◽  
Diversity Partitioning ◽  
Marine Communities ◽  
Geologic Time ◽  
Long Time ◽  
Ancient Ecosystems ◽  
Biotic Invasion

Biotic invasions are a common feature of the fossil record, yet remarkably little is known about them, given their enormous potential to reveal the processes that regulate local and regional diversity over long time scales. We used additive diversity partitioning to examine how diversity structure changed as a result of a marine biotic invasion in tropical, shallow and deep subtidal environments spanning approximately 4 Myr in the Late Ordovician. The biotic invasion increased richness in the regional ecosystem by nearly 40%. Within-habitat turnover diversity accounts for most of the increase in richness, with between-habitat turnover diversity contributing a lesser amount. Increases in these components of diversity were accommodated by increased packing of species along a depth gradient and increased habitat heterogeneity. Diversity metrics that incorporate taxon abundance (Shannon information, Simpson's D) show similar patterns and reveal that many invading taxa were locally abundant and widespread in their occurrence. Extinction of incumbent taxa did not foster the invasion; rather the invasion appears to be linked to a regional or global warming event. Taken together, these observations indicate that these Late Ordovician marine communities were open to invasion and not saturated with species. Moreover, the increase in species diversity caused by the invasion was not ephemeral; instead it lasted for at least 1 Myr. Similar studies of other biotic invasions in the fossil record are necessary to determine (1) the factors, such as extinction of incumbents or resource limitation, that may facilitate or inhibit invasion in ancient ecosystems; (2) how local and regional ecosystems respond to invasion; and (3) the extent to which biotic invasions play a substantial role in ecosystem change through geologic time.

scholarly journals Fossil fern rhizomes as a model system for biotic interactions across geologic time: Evidence from Patagonia

2017 ◽  
Author(s):  
Alexander C. Bippus ◽  
Ignacio H. Escapa ◽  
Peter Wilf ◽  
Alexandru M. F. Tomescu
Keyword(s):  
Fossil Record ◽  
Oribatid Mite ◽  
Biotic Interactions ◽  
Terrestrial Ecosystems ◽  
Model System ◽  
Thin Sections ◽  
Geologic Time ◽  
Ancient Ecosystems ◽  
Plant Plant

Background. A wealth of data on the networks of ecological interactions present in the modern biota can be readily obtained, due to the ease of unlimited access to the living organisms that form these networks. In contrast, understanding of such interactions in ecosystems of the geologic past is incomplete. Specifically, in terrestrial ecosystems we know comparatively little about plant biotic interactions besides herbivory, oviposition, galling. Here we describe a tiny in situ fossil community which sheds light on concurrent plant-plant, plant-fungal, and plant-animal interactions. Methods. A single silicified osmundaceous rhizome from a new locality of the early Eocene (ca. 52 Ma) Tufolitas Laguna del Hunco was studied in serial thin sections using light microscopy. The community of organisms colonizing the tissues of the rhizome was characterized by identifying the organisms, as well as mapping and quantifying their distribution. For this, a 200 x 200 µm grid was superimposed onto the rhizome cross section and the colonizers present at each node of the grid were tallied. Results. Preserved in situ, this community offers a rare window onto aspects of ancient ecosystems usually lost to time and taphonomic processes. The community is surprisingly diverse and includes the first fossilized leafy liverworts in South America, also marking the only fossil record of leafy bryophyte epiphytes; several types of fungal hyphae and spores; microsclerotia with probable affinities in several ascomycete families; and oribatid mite coprolites. Discussion. The community associated with the Patagonian rhizome enriches our understanding of plant biotic interactions in the distant past and adds to a growing body of literature, which indicates that osmundaceous rhizomes were important hosts for component communities in ancient ecosystems, just as they are today. Because osmundaceous rhizomes represent an ecological niche that has remained unchanged over time and space, and are abundant in the fossil record, they provide a good paleoecological model system that could be used for exploring plant biotic interactions across geologic time.

scholarly journals Fossil fern rhizomes as a model system for exploring epiphyte community structure across geologic time: evidence from Patagonia

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8244 ◽  
Author(s):  
Alexander C. Bippus ◽  
Ignacio H. Escapa ◽  
Peter Wilf ◽  
Alexandru M.F. Tomescu
Keyword(s):  
Community Structure ◽  
Fossil Record ◽  
Model System ◽  
Plant Interactions ◽  
Thin Sections ◽  
Geologic Time ◽  
Epiphyte Communities ◽  
Ancient Ecosystems ◽  
Epiphyte Community

Background In extant ecosystems, complex networks of ecological interactions between organisms can be readily studied. In contrast, understanding of such interactions in ecosystems of the geologic past is incomplete. Specifically, in past terrestrial ecosystems we know comparatively little about plant biotic interactions besides saprotrophy, herbivory, mycorrhizal associations, and oviposition. Due to taphonomic biases, epiphyte communities are particularly rare in the plant-fossil record, despite their prominence in modern ecosystems. Accordingly, little is known about how terrestrial epiphyte communities have changed across geologic time. Here, we describe a tiny in situ fossil epiphyte community that sheds light on plant-animal and plant-plant interactions more than 50 million years ago. Methods A single silicified Todea (Osmundaceae) rhizome from a new locality of the early Eocene (ca. 52 Ma) Tufolitas Laguna del Hunco (Patagonia, Argentina) was studied in serial thin sections using light microscopy. The community of organisms colonizing the tissues of the rhizome was characterized by identifying the organisms and mapping and quantifying their distribution. A 200 × 200 µm grid was superimposed onto the rhizome cross section, and the colonizers present at each node of the grid were tallied. Results Preserved in situ, this community offers a rare window onto aspects of ancient ecosystems usually lost to time and taphonomic processes. The community is surprisingly diverse and includes the first fossilized leafy liverworts in South America, also marking the only fossil record of leafy bryophyte epiphytes outside of amber deposits; as well as several types of fungal hyphae and spores; microsclerotia with possible affinities in several ascomycete families; and evidence for oribatid mites. Discussion The community associated with the Patagonian rhizome enriches our understanding of terrestrial epiphyte communities in the distant past and adds to a growing body of literature on osmundaceous rhizomes as important hosts for component communities in ancient ecosystems, just as they are today. Because osmundaceous rhizomes represent an ecological niche that has remained virtually unchanged over time and space and are abundant in the fossil record, they provide a paleoecological model system that could be used to explore epiphyte community structure through time.

scholarly journals Fossil fern rhizomes as a model system for biotic interactions across geologic time: Evidence from Patagonia

2017 ◽  
Author(s):  
Alexander C. Bippus ◽  
Ignacio H. Escapa ◽  
Peter Wilf ◽  
Alexandru M. F. Tomescu
Keyword(s):  
Fossil Record ◽  
Oribatid Mite ◽  
Biotic Interactions ◽  
Terrestrial Ecosystems ◽  
Model System ◽  
Thin Sections ◽  
Geologic Time ◽  
Ancient Ecosystems ◽  
Plant Plant

Background. A wealth of data on the networks of ecological interactions present in the modern biota can be readily obtained, due to the ease of unlimited access to the living organisms that form these networks. In contrast, understanding of such interactions in ecosystems of the geologic past is incomplete. Specifically, in terrestrial ecosystems we know comparatively little about plant biotic interactions besides herbivory, oviposition, galling. Here we describe a tiny in situ fossil community which sheds light on concurrent plant-plant, plant-fungal, and plant-animal interactions. Methods. A single silicified osmundaceous rhizome from a new locality of the early Eocene (ca. 52 Ma) Tufolitas Laguna del Hunco was studied in serial thin sections using light microscopy. The community of organisms colonizing the tissues of the rhizome was characterized by identifying the organisms, as well as mapping and quantifying their distribution. For this, a 200 x 200 µm grid was superimposed onto the rhizome cross section and the colonizers present at each node of the grid were tallied. Results. Preserved in situ, this community offers a rare window onto aspects of ancient ecosystems usually lost to time and taphonomic processes. The community is surprisingly diverse and includes the first fossilized leafy liverworts in South America, also marking the only fossil record of leafy bryophyte epiphytes; several types of fungal hyphae and spores; microsclerotia with probable affinities in several ascomycete families; and oribatid mite coprolites. Discussion. The community associated with the Patagonian rhizome enriches our understanding of plant biotic interactions in the distant past and adds to a growing body of literature, which indicates that osmundaceous rhizomes were important hosts for component communities in ancient ecosystems, just as they are today. Because osmundaceous rhizomes represent an ecological niche that has remained unchanged over time and space, and are abundant in the fossil record, they provide a good paleoecological model system that could be used for exploring plant biotic interactions across geologic time.

USING FOOD WEBS TO EXAMINE ECOSYSTEM DYNAMICS DURING BIOTIC INVASIONS IN LATE ORDOVICIAN SHALLOW MARINE COMMUNITIES

2016 ◽  
Author(s):  
Hannah L. Kempf ◽  
◽  
Ashley A. Dineen ◽  
Peter D. Roopnarine ◽  
Carrie L. Tyler
Keyword(s):  
Food Webs ◽  
Late Ordovician ◽  
Ecosystem Dynamics ◽  
Shallow Marine ◽  
Marine Communities

USING FOOD WEBS TO UNDERSTAND THE EFFECTS OF BIOTIC INVASION ON LATE ORDOVICIAN MARINE COMMUNITY STRUCTURE

2017 ◽  
Author(s):  
Hannah L. Kempf ◽  
◽  
Ian O. Castro ◽  
Carrie L. Tyler ◽  
Ashley A. Dineen ◽  
...  
Keyword(s):  
Community Structure ◽  
Food Webs ◽  
Late Ordovician ◽  
Biotic Invasion ◽  
Marine Community

Did Ground Cover Change Over Geologic Time?

2000 ◽  
Vol 6 ◽  
pp. 171-182 ◽  
Author(s):  
Ben A. LePage ◽  
Hermann W. Pfefferkorn
Keyword(s):  
Fossil Record ◽  
Ground Cover ◽  
The Other ◽  
Detailed Account ◽  
Geologic Time ◽  
The Past ◽  
Other Hand ◽  
Plant Fossil

When one hears the term “ground cover,” one immediately thinks of “grasses.” This perception is so deep-seated that paleobotanists even have been overheard to proclaim that “there was no ground cover before grasses.” Today grasses are so predominant in many environments that this perception is perpetuated easily. On the other hand, it is difficult to imagine the absence or lack of ground cover prior to the mid-Tertiary. We tested the hypothesis that different forms of ground cover existed in the past against examples from the Recent and the fossil record (Table 1). The Recent data were obtained from a large number of sources including those in the ecological, horticultural, and microbiological literature. Other data were derived from our knowledge of Precambrian life, sedimentology and paleosols, and the plant fossil record, especially in situ floras and fossil “monocultures.” Some of the data are original observations, but many others are from the literature. A detailed account of these results will be presented elsewhere (Pfefferkorn and LePage, in preparation).

scholarly journals Major features of protistan evolution: controversies, problems and a few answers

2006 ◽  
Vol 29 (1) ◽  
pp. 55-80
Author(s):  
Jere H Lipps
Keyword(s):  
Fossil Record ◽  
Molecular Data ◽  
Trophic Levels ◽  
Early Earth ◽  
Huge Number ◽  
Geologic Time ◽  
Earth History ◽  
Important Development ◽  
Fossil Evidence

The major features of protist evolution are fraught with controversies, problems and few answers, especially in early Earth history. In general they are based on molecular data and fossil evidence that respectively provide a scaffold and details of eukaryotic phylogenetic and ecologic histories. 1. Their origin, inferred from molecular sequences, occurred very early (>;3Ga). They are a chimera of different symbiont-derived organelles, including possibly the nucleus. 2. The initial diversification of eukaryotes may have occurred early in geologic time. Six supergroups exist today, each with fossils known from the Proterozoic and Phanerozoic. 3. Sex, considered an important development, may have been inherited from bacteria. 4. Precambrian protists were largely pelagic cyst-bearing taxa, but benthic forms were probably quite diverse and abundant. 5. Protists gave rise to animals long before 600 Ma through the choanoflagellates, for which no fossil record exists. 6. Acritarchs and skeletonized protists radiated in the Cambrian (544-530 my). From then on, they radiated and became extinct at all the major events recorded in the metazoan fossil record. 7. Protists dominated major environments (shelves and reefs) starting with a significant radiation in the Ordovician, followed by extinctions and other radiations until most died out at the end of the Permian. 8. In the Mesozoic, new planktic protozoa and algae appeared and radiated in pelagic environments. 9. Modern protists are important at all trophic levels in the oceans and a huge number terrestrial, parasitic and symbiotic protists must have existed for much of geologic time as well. 10. The future of protists is likely in jeopardy, just like most reefal, benthic, and planktic metazoans. An urgent need to understand the role of protists in modern threatened oceans should be addressed soon.

Bias in the published fossil record

Paleobiology ◽  
1978 ◽  
Vol 4 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Carl F. Koch
Keyword(s):  
Species Diversity ◽  
North America ◽  
Normal Distribution ◽  
Fossil Record ◽  
Geologic Time ◽  
Abundance Data ◽  
Significant Bias ◽  
Mollusc Species ◽  
Log Normal ◽  
Log Normal Distribution

The published fossil record has significant bias in favor of common and biostratigraphically important taxa when compared with data obtained from a thorough examination of several hundred collections from the Western Interior of North America. Overall species diversity is underestimated by a factor of 3 to 4, and bivalve and gastropod diversity by a factor of 5. The proportion of bivalves increased from 40 to 56% of the fauna, and the proportion of ammonites decreased from 28 to 18%. Thirteen published reports listed 65 species from 203 reported occurrences. Data from all sources showed 170 species for 1050 occurrences. By using abundance data and assuming a log-normal distribution, as many as 200 fossilizable mollusc species may have inhabited the Western Interior during the uppermost biozone of the Cenomanian. The importance of this study is that it quantifies the bias in the published fossil record relative to the potential fossil record for an unusually well studied interval of geologic time. The bias would be greater for less well studied strata.

scholarly journals Biological basis for taphonomic patterns in the trilobite fossil record

1992 ◽  
Vol 6 ◽  
pp. 34-34
Author(s):  
Danita Brandt
Keyword(s):  
Fossil Record ◽  
Shape Function ◽  
Differential Susceptibility ◽  
Late Ordovician ◽  
Biological Factors ◽  
Ventral Plate ◽  
Similar Shape ◽  
The Impact ◽  
Biological Component ◽  
Successful Predation

Appreciating the biological component of taphonomic patterns is necessary for accurately interpreting the mode of formation of fossiliferous assemblages. This study documents taphonomic patterns in three Late Ordovician trilobite genera (Flexicalymene, Isotelus, Ceraurus) and identifies four biological factors that affect incorporation of trilobite exoskeletal elements into the fossil record:1) Exoskeletal architecture. Recurring patterns of displaced tergites and points of disartiuclation indicate differential susceptibility of the exoskeleton during ecdysis, and presumably also during decay of a carcass. Disolcations are most common at articulation points, e.g., between cephalon and thorax, among thoracic segments, and between the thorax and pygidium. There is no evidence that facial sutures were lines of weakness except during ecdysis.2) Exoskeletal thickness. Thickness is a better predictor of preservation potential than the position, shape, function, or size of a tergite. For example, Ceraurus and Flexicalymene have hypostomata of similar shape and size, but the thicker Ceraurus hypostoma is more frequently preserved (or at least identified) than the thin ventral plate of Flexicalymene.3) Ecdysis. Molting potentially releases the greatest number of trilobite tergites to the fossil record. Molt ensembles are recognized by recurring assemblages of tergites (e.g., thoracopygidia, cephalothorax, multiple thoracic segments) although individual elements (e.g., hypostomata and librigenae) are shed as well. Distinguishing individual molt elements from tergites disarticulated via scavenging or post-mortem transport of carcass or exuvia is problematic. Ecdysis often releases intact exoskeletal elements: most breakage probably occurs later. during post-ecdysial transport or scavenging of the exuvia.4) Predation/scavenging. These effects are characterized by broken (vs. disarticulated) exoskeletal elements. The impact of these processes on the trilobite fossil record is difficult to assess: sublethal wounds are easiest to recognize, the product of successful predation/scavenging is most often unidentifiable comminuted trilobite debris. The products of successful predation/scavenging are identified as such indirectly by their association with the remains of possible predators or by their presence in coprolites.

Community Replacement Pathways: What Do Fossil Sequences Reveal About Marine Ecosystem Transitions?

1990 ◽  
Vol 5 ◽  
pp. 262-272
Author(s):  
William Miller
Keyword(s):  
Fossil Record ◽  
Large Scale ◽  
Marine Ecosystem ◽  
Small Scale ◽  
Data Sets ◽  
Mass Extinctions ◽  
Ultimate Cause ◽  
Long Time ◽  
History Of ◽  
Time And Energy

Paleontologists have lavished much time and energy on description and explanation of large-scale patterns in the fossil record (e.g., mass extinctions, histories of monophyletic taxa, deployment of major biogeographic units), while paying comparatively little attention to biologic patterns preserved only in local stratigraphic sequences. Interpretation of the large-scale patterns will always be seen as the chief justification for the science of paleontology, but solving problems framed by long time spans and large areas is rife with tenuous inference and patterns are prone to varied interpretation by different investigators using virtually the same data sets (as in the controversy over ultimate cause of the terminal Cretaceous extinctions). In other words, the large-scale patterns in the history of life are the true philosophical property of paleontology, but there will always be serious problems in attempting to resolve processes that transpired over millions to hundreds-of-millions of years and encompassed vast areas of seafloor or landscape. By contrast, less spectacular and more commonplace changes in local habitats (often related to larger-scale events and cycles) and attendant biologic responses are closer to our direct experience of the living world and should be easier to interpret unequivocally. These small-scale responses are reflected in the fossil record at the scale of local outcrops.

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