Taxonomy and variability of three Texigryphaea (Bivalvia) species from their Lower Cretaceous (Albian) type localities in New Mexico and Oklahoma

1989 ◽  
Vol 63 (4) ◽  
pp. 454-483 ◽  
Author(s):  
Barry S. Kues
Keyword(s):  
New Mexico ◽  
Local Variation ◽  
Morphological Characters ◽  
The Other ◽  
Ontogenetic Changes ◽  
Free Living ◽  
Marine Communities ◽  
West Texas ◽  
Turbulence Length ◽  
Group Species

The benthic, free-living oyster Texigryphaea was the dominant constituent of many late Albian marine communities in the Texas and southern Western Interior regions. Large topotypic assemblages of three common lower–middle Washita Group species (T. navia and T. pitcheri in Oklahoma and T. tucumcarii in New Mexico) each display considerable morphological variation in valve shape and the proportions and expression of various features. Variation within an assemblage is partly due to ontogenetic changes but is mainly ecophenotypic, with local variation in nature of substrate, water turbulence, length of attachment time, and other factors influencing the final morphology of the mature shell. The T. navia assemblage is distinct in several important morphological characters from the other species, and the differences become more pronounced with growth. Texigryphaea navia appears to have been adapted to relatively firm substrates in moderately agitated conditions, in contrast to the other species, which occupied softer substrates in quieter environments. The essentially contemporaneous T. pitcheri and T. tucumcarii assemblages display much overlap in all measured dimensions of the left valve and in the range of intergrading morphs that compose each assemblage. Accordingly, T. tucumcarii is considered a synonym of T. pitcheri, representing populations of that species that lived in the West Texas-New Mexico area and developed only minor differences from the eastern populations. Within the T. navia topotypic assemblage are specimens intermediate between T. navia and T. pitcheri, and the eastern and western T. pitcheri assemblages contain forms apparently transitional to two other species, T. washitaensis and T. belviderensis. Ecophenotypic variation in the T. pitcheri assemblages appears to be greater than that in European Jurassic Gryphaea species and mirrors to some extent phyletic variation in European Jurassic Gryphaea lineages.

Mecyclothorax palikea sp.n. from the Waianae Range, Oahu, and the biogeographical history of Hawaii's M. flavomarginatus species group (Coleoptera: Carabidae: Moriomorphini)

2011 ◽  
Vol 42 (4) ◽  
pp. 365-384 ◽  
Author(s):  
James K. Liebherr ◽  
Paul D. Krushelnycky
Keyword(s):  
Cladistic Analysis ◽  
Morphological Characters ◽  
Species Group ◽  
The Other ◽  
Terrestrial Environment ◽  
The North ◽  
Northern Areas ◽  
Areas Of Endemism ◽  
History Of ◽  
Group Species

Abstract Mecyclothorax palikea, sp.n. is described from the vicinity of Palikea, southern Waianae Range, Oahu, HI, USA and is assigned to Britton's Mecyclothorax flavomarginatus species group. Cladistic analysis, based on 20 morphological characters and including several outgroup taxa, places Mecyclothorax impunctatus Liebherr of Molokai as adelphotaxon to the other eight species of the group, with subsequent speciation events successively isolating M. sharpi Britton of West Maui versus a clade of seven Oahu species. Phylogenetic relationships among the Oahu clade species posit three historical speciation events vicariating ancestors on the western Waianae and eastern Koolau Ranges. Mecyclothorax palikea is placed as adelphotaxon to M. carteri (Perkins), a species allopatrically distributed to the north in the Waianae, corroborating existence of southern and northern areas of endemism within the Waianae Range. Relative ages of the respective volcanoes housing M. flavomarginatus group species — Waianae (3.7 million years ago), Koolau (2.6 million years ago), Eastern Molokai (1.8 million years ago), West Maui (1.3 million years ago)—imply that ancestral occupation of Oahu by this group occurred subsequent to completion of the shield building phases of Oahu's two volcanoes, Waianae and Koolau. Diversification within the group on Oahu was associated with vicariance events that occurred within a terrestrial environment. Whereas all four species of the M. flavomarginatus group occupying Waianae Range habitats have been observed recently in nature, collection of M. flavomarginatus in 1906 represents the most recent record for any M. flavomarginatus group species in the Koolau Range, indicating the importance of conserving appropriate Waianae Range habitats in order to preserve representative biodiversity in this species group.

scholarly journals TEMPERATURE REGIMES UNDER ROW COVERS IN OVERWINTER ONION TRANSPLANT PRODUCTION

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 858H-858
Author(s):  
David A. Bender
Keyword(s):  
New Mexico ◽  
Soil Surface ◽  
Plant Size ◽  
The Other ◽  
Bare Ground ◽  
Onion Plant ◽  
Heat Unit ◽  
Row Covers ◽  
West Texas ◽  
Temperature Regimes

Two cultivars of onions, `New Mexico Yellow Grano' and `Midstar' were seeded in single bed plots in mid-October 1985 and 1987 for overwinter transplant production. Plots were covered with spunbonded polyester (POL) or tunnels of clear polyethylene (CLR) or microperforated polyethylene (PER) (1985 only) in early November and compared to uncovered controls. Temperatures were monitored 5 cm above the soil surface under the covers in each plot with three parallel-wired thermocouples. Heat unit (HU) accumulation (number of degrees by which the daily mean temp exceeded 0°C) was recorded for each plot and compared with onion plant size. HU accumulation by mid-February 1986 under CLR, POL and PER was 139%, 131% and 113%, respectively, of that over bare ground. In mid-March 1988 cumulative HU under CLR and POL were 192% and 125% of those over bare ground. Plant diameter varied with variety but increased linearly with cumulative HU for all varieties. `New Mexico Yellow Grano' reached the minimum 4 mm size for transplanting at about 1800 HU while `Midstar' required only 1500 HU. CLR produced useable transplants by early March and the other covers by late March. Numbers of useable transplants per meter of bed in mid-March ranged from 3-6 in uncovered plots to 102-153 under PER tunnels, 185-203 under POL and 263-301 under CLR tunnels. CLR tunnels appear to provide sufficient HU accumulation to produce onion plants for transplanting in early March in West Texas.

scholarly journals TEMPERATURE REGIMES UNDER ROW COVERS IN OVERWINTER ONION TRANSPLANT PRODUCTION

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 858h-858
Author(s):  
David A. Bender
Keyword(s):  
New Mexico ◽  
Soil Surface ◽  
Plant Size ◽  
The Other ◽  
Bare Ground ◽  
Onion Plant ◽  
Heat Unit ◽  
Row Covers ◽  
West Texas ◽  
Temperature Regimes

Two cultivars of onions, `New Mexico Yellow Grano' and `Midstar' were seeded in single bed plots in mid-October 1985 and 1987 for overwinter transplant production. Plots were covered with spunbonded polyester (POL) or tunnels of clear polyethylene (CLR) or microperforated polyethylene (PER) (1985 only) in early November and compared to uncovered controls. Temperatures were monitored 5 cm above the soil surface under the covers in each plot with three parallel-wired thermocouples. Heat unit (HU) accumulation (number of degrees by which the daily mean temp exceeded 0°C) was recorded for each plot and compared with onion plant size. HU accumulation by mid-February 1986 under CLR, POL and PER was 139%, 131% and 113%, respectively, of that over bare ground. In mid-March 1988 cumulative HU under CLR and POL were 192% and 125% of those over bare ground. Plant diameter varied with variety but increased linearly with cumulative HU for all varieties. `New Mexico Yellow Grano' reached the minimum 4 mm size for transplanting at about 1800 HU while `Midstar' required only 1500 HU. CLR produced useable transplants by early March and the other covers by late March. Numbers of useable transplants per meter of bed in mid-March ranged from 3-6 in uncovered plots to 102-153 under PER tunnels, 185-203 under POL and 263-301 under CLR tunnels. CLR tunnels appear to provide sufficient HU accumulation to produce onion plants for transplanting in early March in West Texas.

scholarly journals First Description of Ecomorphotypes in Seal Subfamilies

2020 ◽  
Vol 3 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Rahmat SJ
Keyword(s):  
Body Size ◽  
Morphological Characters ◽  
The Other ◽  
Fossil Species ◽  
The Family ◽  
Similarities And Differences ◽  
The Many ◽  
First Time ◽  
Group Species ◽  
Dietary Data

The Family Phocidae consists of four subfamilies, with ecomorphs known only in representatives of the subfamily Phocinae. This study demonstrates that ecological and morphological characters of the other three subfa milies Cystophorinae, Devinophocinae, Monachinae) do not fit precisely into the previously described ecomorphs for Phocinae. These groupings are based on recent seals, but can also be extrapolated to fossil seals based on morphology and probable ecologica l preferences. The separation of taxa by combining morphological, ecological and dietary data is extremely important for demonstrating similarities and differences in both fossil and modern representatives of seals of the Family Phocidae, straying away fro m normal alpha and beta systematics that group species based only on taxonomic relationships. Due to the fragility of cranial remains, the three most commonly found bones (mandible, humerus, femur) are used to group species. Modern seals have specific morp hological features and ecological distinctions (diving depths, environment, diet, body size) similar to those of fossil species, providing a rationale for associating the many dissociated fossil elements. For the first time, seals of all phocids subfamilie s are divided into their corresponding ecomorphs.

Phylogenetic relationships and evolution in the genus Dissodactylus Smith, 1870 (Crustacea: Brachyura: Pinnotheridae)

1987 ◽  
Vol 65 (9) ◽  
pp. 2292-2310 ◽  
Author(s):  
Hugh Griffith
Keyword(s):  
Phylogenetic Relationships ◽  
Sister Group ◽  
Morphological Characters ◽  
The Other ◽  
Free Living ◽  
Evolutionary Scenario ◽  
Species Pairs ◽  
Group Relationships ◽  
Sand Dollars ◽  
Pacific Species

A cladogram indicating sister-group relationships within the pinnotherid crab genus Dissodactylus is constructed from analysis of 28 morphological characters. The outgroup method was used to determine character polarities. Parapinnixa and Sakaina are shown to be a monophyletic group, and are suggested to be the sister group of Dissodactylus. Within Dissodactylus, two mutually exclusive, monophyletic subgroups are found, one containing nine, the other four species. Both of these groups include Atlantic and Pacific representatives. Two Atlantic–Pacific species pairs are suggested to be sister species (D. mellitae–D. glasselli and D. primitivus–D. schmitti). Members of the group of nine species are inhabitants primarily of mellitid sand dollars, although one species, D. primitivus, is a symbiont of heart urchins (Spatangoida). Members of the group of four species are inhabitants of sea biscuits of the genus Clypeaster (Clypeasteridae). An evolutionary scenario is presented, which suggests that a free-living ancestor colonized mellitid sand dollars, and subsequent specializations led to the colonizations of the genus Clypeaster and genera of Spatangoida.

UV ability to inactivate microorganisms combined with factors affecting radiation

1997 ◽  
Vol 35 (11-12) ◽  
pp. 107-112 ◽  
Author(s):  
A. M. Shaban ◽  
G. E. El-Taweel ◽  
G. H. Ali
Keyword(s):  
Microbial Communities ◽  
Uv Radiation ◽  
Contact Time ◽  
Tap Water ◽  
Scenedesmus Obliquus ◽  
Morphological Characters ◽  
The Other ◽  
Bacterial Cells ◽  
Dark Repair ◽  
Nile Water

In the present study, the effect of UV radiation on the inactivation of a range of microorganisms was studied. Each organism was seeded into sterile tap water and exposed to UV in batch experiments with changing turbidities. In addition, the effect of UV on microbial communities in river Nile water was examined. It was found that 1min contact time (0.5L/min flow rate) was effective against vegetative cells levels almost reaching zero (except with Staphylococcus aureus). On the other hand, spore-forming bacteria, Candida albicans and coliphage were more resistant to UV. This contact time caused coenobia cells in single form with Scenedesmus obliquus while for Microcystis aeruginosa colonies broke into smaller groups. Exposure of Nile water microbial communities to UV showed that yeasts and Aeromonas survived better than the other organisms while in the phytoplankton partial fragmentation occurred in some algal groups. The protective effect of turbidity differed between organisms, with increased contact time under conditions of stable turbidity having no effect on the organisms. At 20 NTU the UV radiation had no effect on the morphological characters of algal cells. In reactivation experiments, it is clear that photoreactivation, and not dark repair, takes place with bacterial cells. Only coliphage had no photoreactivation and dark repair responses although with coliphage and host, both reactivation processes worked well. Moreover, the irradiated algae regained their normal shape after 3 days in suitable media and enough light.

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