Ecophenotypic variability during times of evolutionary stasis in Middle DevonianActinopteria(Bivalvia, Pterioidea) from New York

2018 ◽  
Vol 92 (3) ◽  
pp. 388-397 ◽  
Author(s):  
Judith Nagel-Myers ◽  
Christopher A. McRoberts ◽  
Cullen W. LaPoint
Keyword(s):  
New York ◽  
Flow Rate ◽  
Middle Devonian ◽  
Filtration Rate ◽  
Taxonomic Status ◽  
Small Scale ◽  
Bivalve Species ◽  
Single Variable ◽  
Geometric Morphometric ◽  
Evolutionary Stasis

AbstractWe examine the morphological variation of a Paleozoic pterineid during a time of relative ecological and taxonomic stability in the Middle Devonian Appalachian Basin in central and eastern New York. We discuss the taxonomic status of the Middle Devonian bivalveActinopteria boydi(Conrad, 1842) and quantify the variability of its shell disk as well as the width and angle of the auricles and sulci of this otherwise character-poor bivalve species using geometric morphometric techniques employing Cartesian landmarks. We compare variants from three stratigraphic levels (Skaneateles, Ludlowville, and Moscow formations) and from different habitats characterized by lithofacies.The phenotypic variation observed in our data does not amount to an overall directional shift in morphology, i.e., they constitute reversible changes of morphology in a single variable taxon. Our study finds small-scale variation in morphology that represents evidence for ecophenotypic variation through ~3–4 Myr. Differences in substrate coupled with water energy seem to impact this taxon’s morphology. Although no clearly separated groups can be observed, material from muddy facies develops variants with, on average, rounder and broader shell disks than are found in material from silty facies. This morphology could have increased the flow rate of water channeled over the posterior shell portion thereby improving filtration rate, which is especially beneficial in environments with low water energy.

Conodonts from the Prout Dolomite of north-central Ohio and Givetian (upper Middle Devonian) correlation problems

1999 ◽  
Vol 73 (5) ◽  
pp. 892-907 ◽  
Author(s):  
Dale R. Sparling
Keyword(s):  
New York ◽  
New Species ◽  
North America ◽  
Middle Devonian ◽  
Taxonomic Status ◽  
Middle Part ◽  
North Central ◽  
Continuous Sedimentation ◽  
Stratotype Section ◽  
A New Species

The Prout Dolomite of north-central Ohio lies disconformably above the lowest Givetian (upper Middle Devonian) Plum Brook Shale and below the lowest Famennian (upper Upper Devonian) Ohio Shale. A sample from its base yielded over 4,000 diverse conodont specimens. Included isPolygnathus ansatusZiegler and Klapper, 1976, the index species for the MiddlevarcusSubzone, which is not reported from strata of this age in Ontario and Indiana, a fact that long caused their miscorrelation with the LowervarcusSubzone. Also present isP. rhenanusKlapper, Philip, and Jackson, 1970, considered to be also indicative of the MiddlevarcusSubzone in North America, andP. ovatinodosusZiegler and Klapper, 1976. Lowest occurrences of the latter are in the middle part of this subzone; its presence indicates correlation with the lower Tully Limestone of New York, the basal unit of the Taghanic Series. The Prout and equivalent strata in the region therefore represent a long unrecognized continuous time-rock unit created by Johnson's (1970) Taghanic onlap. The collection includes a new species ofAncyrolepis, A. huntleyi; a new species ofPolygnathusis left in open nomenclature, as are nine specimens assigned toTortodusbut of otherwise uncertain taxonomic status.Givetian conodont correlation between North America and the Global Stratotype Section and Point established by the Subcommission on Devonian Stratigraphy (SDS) in Morocco is extremely problematical because of relatively erratic distribution (probably owing to limited ecologic adaptability) ofP. ansatusandP. hemiansatusBultynck, considered herein to be an early morphotype ofP. ansatus.The base of the Givetian Stage has been defined by the SDS as coinciding with the lowest occurrence ofP. hemiansatus.The only possible evidence for the SDS'shemiansatusZone in North America involves reported occurrence of that morphotype in the uppermost Arkona Shale of Ontario, a position above the top of the Plum Brook Shale, which has been considered to be of Givetian age for decades. Also it appears that the interval between the Eifelian (lower Middle Devonian)kockelianusZone and thehemiansatusZone at the SDS's global-stratotype section in Morocco is of questionable age and probably too thin to represent continuous sedimentation. Adoption of a widely recognized faunal break at the base of strata deposited during the If T-R cycle of North America and Europe as the base of the Givetian could provide a sound alternative.

Delthyris sculptilis Hall, 1843 (Brachiopoda) from the Middle Devonian Hamilton Group is a Megakozlowskiella

1986 ◽  
Vol 60 (4) ◽  
pp. 965-967
Author(s):  
William F. Koch
Keyword(s):  
New York ◽  
North America ◽  
Middle Devonian ◽  
Eastern North America ◽  
Upper Limit ◽  
Hamilton Group

Delthyris sculptilis Hall, 1843, from the Middle Devonian Hamilton Group of New York and equivalent rocks elsewhere in eastern North America, has long been assigned to the genus Delthyris or, in certain older studies, to the genus Spirifer. Recent restudy of this brachiopod shows that it belongs to the genus Megakozlowskiella Boucot, 1962. This extends the upper limit of Megakozlowskiella from the Eifelian (Southwood Stage, Onondaga Limestone in New York) to the Givetian (Tioughnioga Stage, Moscow Formation of the Hamilton Group in New York).

scholarly journals Integration of a Solar Parabolic Dish Collector with a Small-Scale Multi-Stage Flash Desalination Unit: Experimental Evaluation, Exergy and Economic Analyses

2021 ◽  
Vol 13 (20) ◽  
pp. 11295
Author(s):  
Ali Babaeebazaz ◽  
Shiva Gorjian ◽  
Majid Amidpour
Keyword(s):  
Solar Radiation ◽  
Flow Rate ◽  
Quality Parameters ◽  
Small Scale ◽  
Conical Cavity ◽  
Multi Stage ◽  
Circulation Circuit ◽  
Parabolic Dish ◽  
Economic Analyses ◽  
The Cost

In this study, a small-scale two-stage multi-stage flash (MSF) desalination unit equipped with a vacuum pump and a solar parabolic collector (PDC) with a conical cavity receiver were integrated. To eliminate the need for heat exchangers, a water circulation circuit was designed in a way that the saline feedwater could directly flow through the receiver of the PDC. The system’s performance was examined during six days in July 2020, from 10:00 a.m. to 3:00 p.m., under two distinct scenarios of the MSF desalination operation under the vacuum (−10 kPa) and atmospheric pressure by considering three saline feedwater water flow rates of 0.7, 1 and 1.3 L/min. Furthermore, the performance of the solar PDC-MSF desalination plant was evaluated by conducting energy and exergy analyses. The results indicated that the intensity of solar radiation, which directly affects the top brine temperature (TBT), and the values of the saline feedwater flow rate have the most impact on productivity. The maximum productivity of 3.22 L per 5 h in a day was obtained when the temperature and saline feedwater flow rate were 94.25 °C (at the maximum solar radiation of 1015.3 W/m2) and 0.7 L/min, respectively, and the MSF was under vacuum pressure. Additionally, it was found that increasing the feedwater flow rate from 0.7 to 1.3 L/min reduces distillate production by 76.4% while applying the vacuum improves the productivity by about 34% at feedwater flow rate of 0.7 L/min. The exergy efficiency of the MSF unit was obtained as 0.07% with the highest share of exergy destruction in stages. The quality parameters of the produced distillate including pH, TDS, EC and DO were measured, ensuring they lie within the standard range for drinking water. Moreover, the cost of freshwater produced by the MSF plant varied from 37 US$/m3 to 1.5 US$/m3 when the treatment capacity increased to 8000 L/day.

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