Evidence of oribatid mite detritivory in Antarctica during the late Paleozoic and Mesozoic

2004 ◽  
Vol 78 (6) ◽  
pp. 1146-1153 ◽  
Author(s):  
Derek W. Kellogg ◽  
Edith L. Taylor

Despite their importance in breaking down lignified tissue today, much is still unknown about the role of mites in the fossil record, especially with reference to the Paleozoic–Mesozoic transition. This study examines permineralized peat from three localities in the central Transantarctic Mountains, ranging in age from Permian to Jurassic, for evidence of diversity and abundance of wood-boring mites. Evidence of mites, in the form of coprolites and tunnels in wood and other tissues, was found at all three localities; the Triassic site included more than 10 times as many wood borings as the Permian site. Our results supplement prior evidence of wood-boring mites during the Mesozoic and thereby fill in the known geologic range of this plant/animal interaction.

Geology ◽  
2003 ◽  
Vol 31 (11) ◽  
pp. 977 ◽  
Author(s):  
John L. Isbell ◽  
Paul A. Lenaker ◽  
Rosemary A. Askin ◽  
Molly F. Miller ◽  
Loren E. Babcock

1991 ◽  
Vol 333 (1267) ◽  
pp. 177-186 ◽  

Some of the earliest Devonian fossils of vascular plants show lesions that may be attributed to plant feeding activity by animals. This is the beginning of a more or less continuous fossil record of plant-animal interactions which extends from the Devonian to the present day. An important feature of pre-Cretaceous material is the evidence from coprolites and gut-contents of spore eating by arthropods. Experiments with living arthropods, of groups represented in the Palaeozoic, show that viable spores can survive passage through the gut in significant numbers. Spore eating could clearly have had a dispersal role of value to the plant, as well as its evident benefit as a source of nutrition for the animal involved. Evidence of wood boring and leaf eating extends from the late Carboniferous onwards. It appears that ‘continuous marginal’ leaf-feeding preceded 'interrupted marginal’ feeding, and that this was in turn followed by ‘non-marginal’ leaf feeding. The latter first appeared in Cretaceous angiosperms. Some diversity of leaf miners and leaf galls are also represented in Cretaceous angiosperm leaf fossils.


Paleobiology ◽  
2020 ◽  
pp. 1-14
Author(s):  
Michelle M. Casey ◽  
Erin E. Saupe ◽  
Bruce S. Lieberman

Abstract Geographic range size and abundance are important determinants of extinction risk in fossil and extant taxa. However, the relationship between these variables and extinction risk has not been tested extensively during evolutionarily “quiescent” times of low extinction and speciation in the fossil record. Here we examine the influence of geographic range size and abundance on extinction risk during the late Paleozoic (Mississippian–Permian), a time of “sluggish” evolution when global rates of origination and extinction were roughly half those of other Paleozoic intervals. Analyses used spatiotemporal occurrences for 164 brachiopod species from the North American midcontinent. We found abundance to be a better predictor of extinction risk than measures of geographic range size. Moreover, species exhibited reductions in abundance before their extinction but did not display contractions in geographic range size. The weak relationship between geographic range size and extinction in this time and place may reflect the relative preponderance of larger-ranged taxa combined with the physiographic conditions of the region that allowed for easy habitat tracking that dampened both extinction and speciation. These conditions led to a prolonged period (19–25 Myr) during which standard macroevolutionary rules did not apply.


2018 ◽  
Vol 115 (47) ◽  
pp. 11941-11946 ◽  
Author(s):  
Erik Trinkaus

Diverse developmental abnormalities and anomalous features are evident in the PleistoceneHomofossil record, varying from minor but rare dental, vertebral, and carpal variants to exceptional systemic disorders. There are currently 75 documented anomalies or abnormalities from 66 individuals, spanning the Pleistocene but primarily from the Late Pleistocene Middle and Upper Paleolithic with their more complete skeletal remains. The expected probabilities of finding these variants or developmental disorders vary from <5% to <0.0001%, based on either recent human incidences or relevant Pleistocene sample distributions. Given the modest sample sizes available for the skeletal or dental elements in question, especially if the samples are appropriately limited in time and geography, the cumulative multiplicative probability of finding these developmental changes is vanishingly small. These data raise questions regarding social survival abilities, differing mortuary treatments of the biologically unusual, the role of ubiquitous stress among these Pleistocene foragers, and their levels of consanguinity. No single factor sufficiently accounts for the elevated level of these developmental variants or the low probability of finding them in the available paleontological record.


Paleobiology ◽  
1994 ◽  
Vol 20 (3) ◽  
pp. 362-367 ◽  
Author(s):  
William I. Ausich ◽  
David L. Meyer

Potential hybrid fossil crinoids, Eretmocrinus magnificus x Eretmocrinus praegravis, are identified from the Lower Mississippian Fort Payne Formation of south-central Kentucky. These are the first fossil hybrid crinoids identified, and one of very few examples of hybrids recognized in the fossil record. Eretmocrinus magnificus x E. praegravis specimens have shapes and calyx plate sculpturing that are morphologically intermediate between well-defined, distinct parent species. Suspected hybrids occur at localities where parent species co-occur and where the parent species are the most abundant; the hybrids occur at what may have been the distributional margins of the parent species; and the mixture of characters on suspected hybrids seems to be morphogenetically partitioned. Parent species are derived from separate lineages within Eretmocrinus, and hybridization is the most probable explanation for these morphologically intermediate specimens. This example highlights the need to consider hybridization as a potential interpretation of intermediate morphologies among fossils and raises questions concerning the impact of hybridization for our interpretation of the fossil record and the role of hybridization in the evolutionary process.


Author(s):  
Ricardo Paredes

The accuracy on taxonomic determinations of palaeontology collections may have significant consequences in estimations of organism diversity through time. This justifies the need of taxonomic standardization of palaeontological collections. The perception of palaeodiversity through Phanerozoic time has significantly improved since the Sepkoski showed the marine invertebrate taxonomic data in diversity graphs, organized in orders (Sepkoski 1978) and families (Sepkoski 1979, Sepkoski 1984). The visual impact of these graphs engaged palaeontologists into gathering quantitative macroevolution in order to better understand marine palaeodiversity. Alroy et al. (2008) presented a rebuilt diversity curve based on genus-level in a large sample record. These and other statistically sound and standardized datasets of fossil occurrences have combined sources as literature, databases, and museum collections data as a foundation. Integration of these datasets with the entire fossil record based on individual specimens in space and time would be the ideal approach to species-level taxonomy standards determinations. An example showing how this approach may be achieved is the use of initiatives such as the Web-based data facility Palaeontology Database (PdB) which includes a large amount of fossil record data from throughout the world. The major advantage of that is to gather institucional and also private palaeontological collections with taxonomy experts validation. The core of these datasets is the taxon, with the species as the expected most reliable unit. Taxonomy is therefore the discipline enrolled in the process with the taxonomist at the centre of the process. Updated taxonomy is crucial to create reliable datasets and a careful approach should prevent biased data due to under- or overestimation of diversity. Palaeontological museum collections are known to be one of the largest repositories of fossil data. Taxonomic standardization of palaeontology collections in the context of a museum should: Engage taxonomists in revising fossil clades of the museum material; Promote networking and museum researcher peers involved in similar collections activities; Avoid replication of errors in taxonomic determinations (e.g. exclusive use of Web-based databases sources of taxonomy); Use type material to compare with the collection specimens; Critically analyse previous taxonomic determinations on old labels and associated specimen information; Promote the accessibility of the collection to the research community; Emphasize digitisation of specimen catalogue records as well as 2D imaging of the specimens. Engage taxonomists in revising fossil clades of the museum material; Promote networking and museum researcher peers involved in similar collections activities; Avoid replication of errors in taxonomic determinations (e.g. exclusive use of Web-based databases sources of taxonomy); Use type material to compare with the collection specimens; Critically analyse previous taxonomic determinations on old labels and associated specimen information; Promote the accessibility of the collection to the research community; Emphasize digitisation of specimen catalogue records as well as 2D imaging of the specimens. These practices are valuable complements to current methodologies adopted to improve the taxonomy of collections, resulting in more reliable data which further enables museum-based research focusing on palaeodiversity estimations.


2006 ◽  
Vol 29 (1) ◽  
pp. 55-80
Author(s):  
Jere H Lipps

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.


2016 ◽  
Vol 12 (10) ◽  
pp. 20150813 ◽  
Author(s):  
Wolfgang Kiessling ◽  
Ádám T. Kocsis

Besides helping to identify species traits that are commonly linked to extinction risk, the fossil record may also be directly relevant for assessing the extinction risk of extant species. Standing geographical distribution or occupancy is a strong predictor of both recent and past extinction risk, but the role of changes in occupancy is less widely assessed. Here we demonstrate, based on the Cenozoic fossil record of marine species, that both occupancy and its temporal trajectory are significant determinants of risk. Based on extinct species we develop a model on the additive and interacting effects of occupancy and its temporal changes on extinction risk. We use this model to predict extinction risk of extant species. The predictions suggest a moderate risk for marine species on average. However, some species seem to be on a long-term decline and potentially at a latent extinction risk, which is not considered in current risk assessments.


Sign in / Sign up

Export Citation Format

Share Document