scholarly journals Ecophenotypic variation and phylogeny within the Erisocrinacea (Crinoidea): linkage of morphology, ecology, & sea - level in the Late Paleozoic

1992 ◽  
Vol 6 ◽  
pp. 131-131
Author(s):  
Peter F. Holterhoff
Keyword(s):  
Body Size ◽  
Sea Level ◽  
Maximum Size ◽  
Intermediate Frequency ◽  
Characteristic Size ◽  
Second Order ◽  
Metabolic Energy ◽  
Lower Permian ◽  
Early Permian ◽  
Fifth Order

Cyclothems (fifth - order depositional sequences) are the fundamental stratigraphic motif of the Upper Pennsylvanian and Lower Permian of the North American mid - continent. Through this interval, sequences display an overall second order regression modulated by intermediate frequency sea-level fluctuations. Thus, shelfward incursions of offshore (basinal) facies are more extensive in the lower Upper Pennsylvanian, while merely shoaling facies characterize marine units of many higher sequences.Within basal Upper Pennsylvanian (Missourian) sequences, species of the Erisocrinacea are ubiquitous members of nearshore and offshore crinoid assemblages. However, the species Erisocrinus typus and Delocrinus subhemisphericus display significant ecophenotypic variation between facies: smaller mean and maximum size characterizes offshore/transgressive populations while larger size characterizes nearshore/regressive populations. It is proposed that these are hydrographically - controlled phenotypes: offshore, quiet bottom waters inhibit effective filtration, imposing a metabolic energy threshold beyond which larger morphologies are not viable while nearshore populations are able to assume larger body sizes.Shifting now to the Catacrinidae within the Erisocrinacea, as the frequency of interbasinal drowned shelf conditions waned through the Late Pennsylvanian, new species, inhabiting regressive facies, increased maximum body size and diversity for the family. Thus, lower Virgilian assemblages are highly variable in characteristic size, with smaller, ancestral D. subhemisphericus dominant in offshore facies while robust D. vulgatus, Pyndaxocrinus sp., and Arrectocrinus sp. dominate nearshore facies. Speciation may have involved the stabilization and subsequent diversification of the earlier nearshore phenotype.Through the remainder of the Virgilian and into the Early Permian, near the terminal late Early Permian regression, larger morphologies, represented by D. brownsvillensis, D. vastus, and A. abruptus, dominate midcontinent crinoid assemblages; smaller offshore species had been lost, thus increasing body size for the clade as a whole.Thus, it appears that the same parameters which controlled morphological expression at the fifth - order level (ecophenotypic variation) may also have acted at the second - order level (phylogenetic trend). The interrelationship between sub-cycle and super-cycle sea - level and metabolic viability is paramount to understanding potential morphologies for this clade. However, these factors may not have ultimately influenced clade diversity.

Transgressive–regressive (T–R) sequence analysis of the Jurassic succession of the Sverdrup Basin, Canadian Arctic Archipelago

1993 ◽  
Vol 30 (2) ◽  
pp. 301-320 ◽  
Author(s):  
A. F. Embry
Keyword(s):  
Sequence Analysis ◽  
Sea Level ◽  
Second Order ◽  
Sea Level Changes ◽  
Third Order ◽  
Sverdrup Basin ◽  
Sequence Boundaries ◽  
Boundary Characteristics ◽  
Fifth Order ◽  
Order Sequence

Transgressive–regressive (T–R) sequence analysis has been applied to the Jurassic succession of the Sverdrup Basin with sequence boundaries drawn at subaerial unconformities or the correlative transgressive surfaces. A hierarchal system of sequence order that reflects the different nature of the boundaries has been formulated on the basis of boundary characteristics. Second- through fifth-order sequences have been recognized in the Jurassic succession, which itself is part of a first-order sequence of mid-Permian – Early Cretaceous age.The Jurassic strata occur within four second-order sequences. The boundaries of these sequences are characterized by widespread subaerial unconformities across which major changes in depositional and subsidence regimes occur. These boundaries are earliest Rhaetian, earliest Pliensbachian, earliest Bajocian, earliest Oxfordian, and Hauterivian in age.Each second-order sequence is divisible into a number of third-order sequences bounded mainly by basin-wide transgressive surfaces with subaerial unconformities present on the basin margins. The ages of the 10 Jurassic third-order sequences are Rhaetian – Hettangian, Sinemurian, Pliensbachian – Toarcian, late Toarcian – Aalenian, Bajocian, Bathonian, Callovian, Oxfordian – early Kimmeridgian, late Kimmeridgian – early Tithonian, and late Tithonian. The third-order sequences commonly contain three to six fourth-order sequences. These sequences are bound entirely by transgressive surfaces that can be correlated only over a portion of the basin.A good correlation between the second- and third-order transgressive events of the Sverdrup Basin and proposed global events is observed. This worldwide occurrence suggests that the events in part reflect eustatic sea-level changes. The characteristics of the second- and third-order boundaries also indicate that each had a tectonic influence that resulted in a rapid relative sea-level fall (uplift) followed by a rapid rise (subsidence). Given the apparent combination of tectonic and eustatic influence on the generation of the second- and third-order sequence boundaries, they are interpreted to reflect significant plate-tectonic reorganizations that affected the intraplate stress regimes of the oceanic (eustatic) and continental (tectonic) portions of each lithospheric plate.

scholarly journals Intraspecific Variation in Maximum Ingested Food Size and Body Mass in Varecia rubra and Propithecus coquereli

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Adam Hartstone-Rose ◽  
Jonathan M. G. Perry
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Individual Variation ◽  
Size Variation ◽  
Maximum Size ◽  
Least Squares Regression ◽  
Scaling Relationship ◽  
Varecia Rubra ◽  
Food Size ◽  
The Relationship

In a recent study, we quantified the scaling of ingested food size (Vb )—the maximum size at which an animal consistently ingests food whole—and found that Vb scaled isometrically between species of captive strepsirrhines. The current study examines the relationship between Vb and body size within species with a focus on the frugivorous Varecia rubra and the folivorous Propithecus coquereli. We found no overlap in Vb between the species (all V. rubra ingested larger pieces of food relative to those eaten by P. coquereli), and least-squares regression of Vb and three different measures of body mass showed no scaling relationship within each species. We believe that this lack of relationship results from the relatively narrow intraspecific body size variation and seemingly patternless individual variation in Vb within species and take this study as further evidence that general scaling questions are best examined interspecifically rather than intraspecifically.

The rise and fall of late Paleozoic trilobites of the United States

1999 ◽  
Vol 73 (2) ◽  
pp. 164-175 ◽  
Author(s):  
David K. Brezinski
Keyword(s):  
United States ◽  
North America ◽  
Sea Level ◽  
Adaptive Radiation ◽  
The United States ◽  
Upper Permian ◽  
Late Paleozoic ◽  
Lower Permian ◽  
Stage 4 ◽  
Stage 1

Based on range data and generic composition, four stages of evolution are recognized for late Paleozoic trilobites of the contiguous United States. Stage 1 occurs in the Lower Mississippian (Kinderhookian-Osagean) and is characterized by a generically diverse association of short-ranging, stenotopic species that are strongly provincial. Stage 2 species are present in the Upper Mississippian and consist of a single, eurytopic, pandemic genus, Paladin. Species of Stage 2 are much longer-ranging than those of Stage 1, and some species may have persisted for as long as 12 m.y. Stage 3 is present within Pennsylvanian and Lower Permian strata and consists initially of the eurytopic, endemic genera Sevillia and Ameura as well as the pandemic genus Ditomopyge. During the middle Pennsylvanian the very long-ranging species Ameura missouriensis and Ditomopyge scitula survived for more than 20 m.y. During the late Pennsylvanian and early Permian, a number of pandemic genera appear to have immigrated into what is now North America. Stage 4 is restricted to the Upper Permian (late Leonardian-Guadalupian) strata and is characterized by short-ranging, stenotopic, provincial genera.The main causal factor controlling the four-stage evolution of late Paleozoic trilobites of the United States is interpreted to be eustacy. Whereas Stage 1 represents an adaptive radiation developed during the Lower Mississippian inundation of North America by the Kaskaskia Sequence, Stage 2 is present in strata deposited during the regression of the Kaskaskia sea. Stage 3 was formed during the transgression and stillstand of the Absaroka Sequence and, although initially endemic, Stage 3 faunas are strongly pandemic in the end when oceanic circulation patterns were at a maximum. A mid-Leonardian sea-level drop caused the extinction of Stage 3 fauna. Sea-level rise near the end of the Leonardian and into the Guadalupian created an adaptive radiation of stentopic species of Stage 4 that quickly became extinct with the latest Permian regression.

scholarly journals Charcoal remains from a tonstein layer in the Faxinal Coalfield, Lower Permian, southern Paraná Basin, Brazil

2011 ◽  
Vol 83 (2) ◽  
pp. 471-481 ◽  
Author(s):  
André Jasper ◽  
Dieter Uhl ◽  
Margot Guerra-Sommer ◽  
Abdalla M. B Abu Hamad ◽  
Neli T. G Machado
Keyword(s):  
Lower Permian ◽  
Published Data ◽  
Early Permian ◽  
Ash Fall ◽  
Potential Source ◽  
Volcanic Events ◽  
Paraná Basin ◽  
Surrounding Areas ◽  
Parana Basin

Fossil charcoal has been discovered in the Faxinal Coalfield, Early Permian, Rio Bonito Formation, in the southernmost portion of the Paraná Basin, Brazil. Three types of pycnoxylic gymnosperm woods recovered from a single tonstein layer are described and confirm the occurrence of paleowildfire in this area. A decrease of the charcoal concentration from the base to the top within the tonstein layer indicates that the amount of fuel declined during the deposition probably due to the consumption of vegetation by the fire. The presence of inertinite in coals overlying and underlying the tonstein layer indicates that fire-events were not restricted to the ash fall interval. The integration of the new data presented in the current study with previously published data for the Faxinal Coalfield demonstrates that volcanic events that occurred in the surrounding areas can be identified as one potential source of ignition for the wildfires. The presence of charcoal in Permian sediments associated with coal levels at different localities demonstrates that wildfires have been relatively common events in the peat-forming environments in which the coal formation took place in the Paraná Basin.

Early Permian colonial rugose corals from the Stikine River area, British Columbia, Canada

1989 ◽  
Vol 63 (2) ◽  
pp. 158-181 ◽  
Author(s):  
Calvin H. Stevens ◽  
Barbara Rycerski
Keyword(s):  
British Columbia ◽  
New Species ◽  
Lower Permian ◽  
Early Permian ◽  
Klamath Mountains ◽  
Coral Fauna ◽  
Rugose Corals ◽  
Two New Species ◽  
Three New Species ◽  
One New Species

Twenty-two species of Early Permian colonial rugose corals belonging to 12 genera from 10 locations in the Stikine River area in northwestern British Columbia, Canada, are described. These include three new species ofFomichevella(F. magna, F. southeri, F. bamberi); two species ofHeintzella; five species ofHeritschioides, of which three are new (H. bagleyae, H. garvinae, H. hoganae); two new species ofParaheritschioides(P. jennyi, P. wickenae); one new species questionably assigned toKleopatrina(K.?stikinensis); two new species ofPetalaxis(P. guaspariniae, P. neriae); and two new species ofLytvophyllum(L.?mongeri, L. wersoni). In addition, five new species assigned to five new genera are here namedEastonastraea complexa, Fedorowskiella simplex, Pararachnastraea lewisi, Stikineastraea thomasi, andWilsonastraea rigbyi.These corals occur in rocks forming part of the Stikine terrane, the largest tectonostratigraphic unit in western Canada. This coral fauna shows a very close affinity with that of the Lower Permian McCloud Limestone of the eastern Klamath Mountains of northern California, and there is some similarity to the Coyote Butte fauna of central Oregon. Several species compare most closely with species from Spitsbergen, but there are few similarities with any cratonal North American faunas and none with Tethyan faunas.

scholarly journals Biology, not environment, drives major patterns in maximum tetrapod body size through time

2012 ◽  
Vol 8 (4) ◽  
pp. 674-677 ◽  
Author(s):  
Roland B. Sookias ◽  
Roger B. J. Benson ◽  
Richard J. Butler
Keyword(s):  
Body Size ◽  
Environmental Factors ◽  
Abiotic Factors ◽  
Logistic Models ◽  
Growth Curves ◽  
Maximum Size ◽  
Generalized Least Squares ◽  
Least Squares Regression ◽  
Geological Time ◽  
Cenozoic Mammals

Abiotic and biological factors have been hypothesized as controlling maximum body size of tetrapods and other animals through geological time. We analyse the effects of three abiotic factors—oxygen, temperature and land area—on maximum size of Permian–Jurassic archosauromorphs and therapsids, and Cenozoic mammals, using time series generalized least-squares regression models. We also examine maximum size growth curves for the Permian–Jurassic data by comparing fits of Gompertz and logistic models. When serial correlation is removed, we find no robust correlations, indicating that these environmental factors did not consistently control tetrapod maximum size. Gompertz models—i.e. exponentially decreasing rate of size increase at larger sizes—fit maximum size curves far better than logistic models. This suggests that biological limits such as reduced fecundity and niche space availability become increasingly limiting as larger sizes are reached. Environmental factors analysed may still have imposed an upper limit on tetrapod body size, but any environmentally imposed limit did not vary substantially during the intervals examined despite variation in these environmental factors.

Aspects of the postcranial skeleton of the Lower Permian lungfish, Gnathorhiza

1989 ◽  
Vol 63 (6) ◽  
pp. 919-930 ◽  
Author(s):  
Walter W. Dalquest ◽  
M. John Kocurko ◽  
John V. Grimes
Keyword(s):  
Axial Skeleton ◽  
Lower Permian ◽  
Fish Scales ◽  
Early Permian ◽  
Postcranial Skeleton ◽  
Caudal Fin ◽  
North Central ◽  
New Information ◽  
Central Texas ◽  
Median Fins

A newly discovered locality of aestivation burrow casts containing the lungfish, Gnathorhiza serrata, is reported from the early Permian Arroyo Formation of Wilbarger County, north-central Texas. Remains preserved in the burrow casts provide sections of mummified Gnathorhiza and new information about the postcranial skeleton of this fish. Scales of Gnathorhiza resemble those of the modern lungfishes such as Lepidosiren in their microanatomy. No traces of paddle-like pectoral or pelvic fins were found and paired fins of Gnathorhiza may have resembled those of Lepidosiren. The axial skeleton and median fins of Gnathorhiza seem to resemble those of Lepidosiren except that the tail area and caudal fin of Gnathorhiza were stout and strong rather than slender and tapering. Gnathorhiza, which aestivated tail-down in its burrow, may have required a stout tail for support.

A giant Permian fusulinid from east-central Alaska with comparisons of all giant fusulinids in western North America

1995 ◽  
Vol 69 (5) ◽  
pp. 805-812 ◽  
Author(s):  
Calvin H. Stevens
Keyword(s):  
North America ◽  
Related Species ◽  
The Other ◽  
Lower Permian ◽  
Early Permian ◽  
Western North America ◽  
Closely Related Species ◽  
East Central ◽  
West Texas ◽  
Species Groups

The discovery of a new locality yielding giant Guadalupian (Lower Permian) fusulinids in east-central Alaska extends the range of these forms much farther north than previously known, and into a tectonostratigraphic terrane from which they previously had not been reported. The number of areas from which giant parafusulinids are known in North America is thus raised to eight. Three of these localities are in rocks that previously had been referred to the allochthonous McCloud belt arc, and one, West Texas, is known to have been part of Paleozoic North America. Comparison of species from all areas suggests that there are two closely related species groups: one represented in Texas and Coahuila, and the other represented in Sonora, northern California, northeastern Washington, southern and northern British Columbia, Alaska, and apparently in Texas. These groups may differ because they are of slightly different ages or because interchange between the faunas of Texas–Coahuila area and the other regions was somewhat inhibited during the Early Permian.

scholarly journals Frequency matching of vocalizations to inner-ear sensitivity along an altitudinal gradient in the coqui frog

2009 ◽  
Vol 6 (2) ◽  
pp. 278-281 ◽  
Author(s):  
Sebastiaan W. F. Meenderink ◽  
Mirja Kits ◽  
Peter M. Narins
Keyword(s):  
Body Size ◽  
Inner Ear ◽  
Sea Level ◽  
Otoacoustic Emissions ◽  
Altitudinal Gradient ◽  
Distortion Product Otoacoustic Emissions ◽  
Frequency Range ◽  
Frequency Matching ◽  
Distortion Product ◽  
Sensitivity Change

Acoustic communication involves both the generation and the detection of a signal. In the coqui frog ( Eleutherodactylus coqui ), it is known that the spectral contents of its calls systematically change with altitude above sea level. Here, distortion product otoacoustic emissions are used to assess the frequency range over which the inner ear is sensitive. It is found that both the spectral contents of the calls and the inner-ear sensitivity change in a similar fashion along an altitudinal gradient. As a result, the call frequencies and the auditory tuning are closely matched at all altitudes. We suggest that the animal's body size determines the frequency particulars of the call apparatus and the inner ear.

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