Trace Fossils and Bioturbation: The Other Fossil Record

1992 ◽  
Vol 23 (1) ◽  
pp. 339-360 ◽  
Author(s):  
T P Crimes ◽  
M L Droser
Keyword(s):  
Fossil Record ◽  
Trace Fossils ◽  
The Other

Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Phylogenetic Trees ◽  
Charles Darwin ◽  
The Other ◽  
Charles Lyell ◽  
Single Origin ◽  
Molecular Studies ◽  
Richard Owen ◽  
First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

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).

Foot scales in the Early Cretaceous bird Gansus from China provide evidences on the evolution of avian scales

2021 ◽  
Author(s):  
Tao Zhao ◽  
Zhiheng Li ◽  
He Zhang ◽  
Yanhong Pan
Keyword(s):  
Signaling Pathway ◽  
Early Cretaceous ◽  
Fossil Record ◽  
The Other ◽  
Signaling Modules

Abstract Most modern birds have scales covering the foot, while our knowledge of early avian scales is limited, mainly due to the scarcity of fossil record. Here we characterize the morphological details of two types of scales preserved in IVPP V15077, a referred specimen of the Early Cretaceous bird Gansus. The scutellate and interstitial scales, which, in combination with previous discovery of scutate and reticulate scales in other Early Cretaceous birds, indicates that all four types present in modern birds have appeared in the Early Cretaceous. A phylogenetic context of fossilized scales suggests that the evolution of reticulate scales is conservative while that of the other types is more variable. It is consistent with the molecular hypothesis of the scales in modern birds and reptiles that most integumentary structures in amniotes are homologous with modified signaling modules to form various integumentary phenotypes, among which the reticulate scales may use the conserved signaling pathway.

Stratigraphic biases in the analysis of taxonomic survivorship

Paleobiology ◽  
1975 ◽  
Vol 1 (4) ◽  
pp. 343-355 ◽  
Author(s):  
J. John Sepkoski
Keyword(s):  
Simple Model ◽  
Lognormal Distribution ◽  
Fossil Record ◽  
The Other ◽  
Time Intervals ◽  
Survivorship Analysis ◽  
Other Hand ◽  
Incomplete Sampling ◽  
Biologic Factors

Taxonomic survivorship curves may reflect stratigraphic as well as biologic factors. The approximately lognormal distribution of lengths of Phanerozoic time intervals produces an error in the estimation of taxonomic durations that is also lognormally distributed. As demonstrated by several simulated examples, this error may cause concave taxonomic survivorship curves to appear linear, especially if the maximum durations involved are relatively short. The error of estimation also makes highly concave taxonomic survivorship curves virtually unrecognizable. Incomplete sampling of the fossil record, on the other hand, may not be a serious problem in survivorship analysis. Simulated paleontological sampling employing a simple model suggests that survivorship curves tend to retain their original shapes even when as few as 20% of the taxa have been discovered. However, concave taxonomic survivorship curves tend to lose their concavity as efficiency of sampling declines.

scholarly journals Early fossil record of Euarthropoda and the Cambrian Explosion

2018 ◽  
Vol 115 (21) ◽  
pp. 5323-5331 ◽  
Author(s):  
Allison C. Daley ◽  
Jonathan B. Antcliffe ◽  
Harriet B. Drage ◽  
Stephen Pates
Keyword(s):  
Fossil Record ◽  
Trace Fossils ◽  
Cambrian Explosion ◽  
Burgess Shale ◽  
Crown Group ◽  
Total Group ◽  
Stem Lineage ◽  
Coherent Picture ◽  
Insight Into ◽  
Phosphate Deposits

Euarthropoda is one of the best-preserved fossil animal groups and has been the most diverse animal phylum for over 500 million years. Fossil Konservat-Lagerstätten, such as Burgess Shale-type deposits (BSTs), show the evolution of the euarthropod stem lineage during the Cambrian from 518 million years ago (Ma). The stem lineage includes nonbiomineralized groups, such as Radiodonta (e.g., Anomalocaris) that provide insight into the step-by-step construction of euarthropod morphology, including the exoskeleton, biramous limbs, segmentation, and cephalic structures. Trilobites are crown group euarthropods that appear in the fossil record at 521 Ma, before the stem lineage fossils, implying a ghost lineage that needs to be constrained. These constraints come from the trace fossil record, which show the first evidence for total group Euarthropoda (e.g., Cruziana, Rusophycus) at around 537 Ma. A deep Precambrian root to the euarthropod evolutionary lineage is disproven by a comparison of Ediacaran and Cambrian lagerstätten. BSTs from the latest Ediacaran Period (e.g., Miaohe biota, 550 Ma) are abundantly fossiliferous with algae but completely lack animals, which are also missing from other Ediacaran windows, such as phosphate deposits (e.g., Doushantuo, 560 Ma). This constrains the appearance of the euarthropod stem lineage to no older than 550 Ma. While each of the major types of fossil evidence (BSTs, trace fossils, and biomineralized preservation) have their limitations and are incomplete in different ways, when taken together they allow a coherent picture to emerge of the origin and subsequent radiation of total group Euarthropoda during the Cambrian.

scholarly journals Fossil-calibrated molecular phylogeny of atlantid heteropods (Gastropoda, Pterotracheoidea)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Deborah Wall-Palmer ◽  
Arie W. Janssen ◽  
Erica Goetze ◽  
Le Qin Choo ◽  
Lisette Mekkes ◽  
...  
Keyword(s):  
Fossil Record ◽  
Large Scale ◽  
Global Scale ◽  
The Other ◽  
The Past ◽  
The Family ◽  
Rapid Diversification ◽  
Maximum Likelihood Phylogeny ◽  
Extinction Events ◽  
Ribosomal Rrna

Abstract Background The aragonite shelled, planktonic gastropod family Atlantidae (shelled heteropods) is likely to be one of the first groups to be impacted by imminent ocean changes, including ocean warming and ocean acidification. With a fossil record spanning at least 100 Ma, atlantids have experienced and survived global-scale ocean changes and extinction events in the past. However, the diversification patterns and tempo of evolution in this family are largely unknown. Results Based on a concatenated maximum likelihood phylogeny of three genes (cytochrome c oxidase subunit 1 mitochondrial DNA, 28S and 18S ribosomal rRNA) we show that the three extant genera of the family Atlantidae, Atlanta, Protatlanta and Oxygyrus, form monophyletic groups. The genus Atlanta is split into two groups, one exhibiting smaller, well ornamented shells, and the other having larger, less ornamented shells. The fossil record, in combination with a fossil-calibrated phylogeny, suggests that large scale atlantid extinction was accompanied by considerable and rapid diversification over the last 25 Ma, potentially driven by vicariance events. Conclusions Now confronted with a rapidly changing modern ocean, the ability of atlantids to survive past global change crises gives some optimism that they may be able to persist through the Anthropocene.

Trace Fossils in Quaternary, Bahamian-Style Carbonate Environments: The Modern to Fossil Transition

1992 ◽  
Vol 5 ◽  
pp. 105-120 ◽  
Author(s):  
H. Allen Curran
Keyword(s):  
Fossil Record ◽  
Trace Fossils ◽  
Subtidal Zone ◽  
Carbonate Sediments ◽  
Shallow Marine ◽  
Shallow Subtidal ◽  
Dominant Process ◽  
Burrowing Activity

Tracemaking organisms are common and diverse components of the fauna and flora of tropical, shallow-marine and coastal carbonate environments. In the shallow subtidal zone, the burrowing activity of callianassid shrimp commonly is the dominant process in the modification of original depositional fabrics (Tudhope and Scoffin, 1984; Tedesco and Wanless, 1991). Both borers and burrowers have great potential to leave their mark in tropical carbonate sediments and rocks and to become part of the fossil record.

Long/Short Term Influences on Change

1999 ◽  
Vol 9 ◽  
pp. 309-318
Author(s):  
Kaustuv Roy
Keyword(s):  
Fossil Record ◽  
The Other ◽  
Short Term ◽  
Geologic Time ◽  
Number Of Species ◽  
Higher Taxa ◽  
Terrestrial Habitats ◽  
History Of ◽  
Using Data ◽  
Over Time

Change has been the rule in the history of life. Mammals today dominate the terrestrial habitats where dinosaurs once held sway. In modern oceans, ecologists can study many species of arthropods, but trilobites are long gone. Using data from the fossil record, David Raup estimated that only about one in a thousand species that ever lived on this planet is still alive today (Raup, 1991). On the other hand, the number of species and higher taxa has increased steadily over geologic time. Thus the history of life is essentially a history of turnover of species, lineages and higher taxa over time.

Evolutionary trends and ecology of Mesozoic decapod crustaceans

1985 ◽  
Vol 76 (2-3) ◽  
pp. 299-304 ◽  
Author(s):  
Reinhard Förster
Keyword(s):  
Fossil Record ◽  
Trace Fossils ◽  
Evolutionary Trends ◽  
Decapod Crustaceans ◽  
Gradual Reduction ◽  
Successful Method

ABSTRACTThe fossil record of unquestionable decapod remains dates back to Permo Triassic times. Evaluation of all available data from the fossil record, trace fossils and facies reveals various trends within the evolution of Mesozoic decapods, and its relation to their ecology. One of these trends is the protection of the long vulnerable abdomen. The most successful method, gradual reduction and inflection of the abdomen against the ventral cephalothorax, led to the Brachyura. Brachyurans exhibit the broadest spectrum of habitat adaptions.

Lower Palaeozoic trace fossils from eastern Newfoundland

1976 ◽  
Vol 13 (11) ◽  
pp. 1613-1633 ◽  
Author(s):  
Jan Bergström
Keyword(s):  
Short Review ◽  
Trace Fossils ◽  
The Other ◽  
Lower Palaeozoic ◽  
Local Geology ◽  
Conception Bay

Arthropod trace fossils are described from the Cambro-Ordovician sequence of Conception Bay. The sedimentological and ichnofaunal aspect is typical of an Acado-Mediterranean Province, but a few unique forms occur, including Rusophycus leifeirikssoni n. ichnosp. and R. cf. R. jenningsi. An effort is made to separate telopodite and exite scratches and to understand what kinds of trilobites were involved. Together with the description of the arthropod trace fossils, a list of the other trace fossils and short review of the local geology is given.

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