Lost in the Other Half: Improving Accuracy in Geometric Morphometric Analyses of One Side of Bilaterally Symmetric Structures

A new medium-sized species of Hippodonta (Bacillariophyceae) is described from Lake Qinghai, China. The morphology and ultrastructure of Hippodonta qinghainensis sp. nov. are described using light and scanning electron microscopy. This new species is compared with similar species of Hippodonta using conventional and geometric morphometric analyses. Hippodonta qinghainensis can be separated from the other species of Hippodonta by a unique combination of characters that include an elliptic-lanceolate to rhombic-lanceolate valve shape, non protracted apices, the absence of fascia, relatively coarse, uniseriate striae and the presence of two rows of lineolae around the valves apices.

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Filtration by superficial and deep glomeruli of normovolemic and volume-depleted rats

AJP Renal Physiology ◽

10.1152/ajprenal.1986.250.1.f86 ◽

1986 ◽

Vol 250 (1) ◽

pp. F86-F91

Author(s):

R. V. Pinnick ◽

V. J. Savin

Keyword(s):

Basement Membrane ◽

Maximum Rate ◽

Rate Of Change ◽

The Other ◽

Membrane Area ◽

Morphometric Analyses ◽

Three Samples ◽

Glomerular Size ◽

Glomerular Ultrafiltration

We measured glomerular ultrafiltration coefficient (Kf) of isolated superficial (S) and deep (D) glomeruli of normovolemic and volume-depleted rats. Filtration was induced in vitro, and Kf was calculated from the maximum rate of change in glomerular size. Basement membrane area (A) for each glomerulus was estimated from morphometric analyses, and glomerular capillary hydraulic conductivity (Lp) was calculated by the formula Lp = Kf/A. Kf of S and D glomeruli of normovolemic rats were 2.98 +/- 0.98 and 4.25 +/- 0.07 nl . min-1 . mmHg-1, respectively. In hypovolemic rats, Kf of S glomeruli fell by approximately 50% to 1.52 +/- 0.14 nl . min-1 . mmHg-1 (P less than 0.001), whereas Kf of D glomeruli remained unchanged at 4.28 +/- 0.10 nl . min-1 . mmHg-1. Lp, calculated using the peripheral capillary area, averaged 1.98 +/- 0.09 and 1.98 +/- 0.06 microliter . min-1 . mmHg-1 . cm-2 in S and D glomeruli of normovolemic rats and 1.89 +/- 0.11 microliter . min-1 . mmHg-1 . cm-2 in D glomeruli of hypovolemic rats. Lp of S glomeruli of volume-depleted rats (0.90 +/- 0.03 microliter . min-1 . mmHg-1 . cm-2) was lower than in any of the other three samples. Mild hypovolemia causes the Kf of S glomeruli to decline, whereas Kf of D glomeruli remains constant. The decrease in Kf occurs without an alteration in capillary area and is most likely due to a decrease in Lp.

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Comparison of histometric and morphometric analyses of bone height in ligature-induced periodontitis in rats

Brazilian Oral Research ◽

10.1590/s1806-83242007000300005 ◽

2007 ◽

Vol 21 (3) ◽

pp. 216-221 ◽

Cited By ~ 31

Author(s):

Marilene Issa Fernandes ◽

Eduardo José Gaio ◽

Rui Vicente Oppermann ◽

Pantelis Varvaki Rados ◽

Cassiano Kuchenbecker Rosing

Keyword(s):

Periodontal Disease ◽

Morphometric Analysis ◽

Wistar Rats ◽

T Test ◽

The Other ◽

Limited Capacity ◽

Height Measurement ◽

Morphometric Analyses ◽

Left And Right ◽

Bone Height

The purpose of this study was to compare histologic and morphometric procedures of bone height measurement. Microscopic measurements are the most frequent methods in periodontal studies with animals, but have limited capacity to identify bone levels associated with both healthy tissues and periodontal disease. Ligatures were placed in the maxillary left second molars of 10 male 60-day-old Wistar rats for 30 days. Left and right maxillary sides of 5 rats were processed for histologic analysis (H), sectioned buccolingually, and stained with HE. The maxillae of the other 5 rats were defleshed and used for morphometric analysis (M). Histometric measurements from the cementoenamel junction to the bone crest were performed. Standardized photographs were used for morphometric analysis. The t test was used for dependent or independent samples (alpha = 0.05%). Distances from cementoenamel junction to bone crest were 0.95 ± 0.25 and 1.07 ± 0.30 mm for H and M, respectively. Buccal measurements were 0.92 ± 0.16 and 1.08 ± 0.35 mm for H and M. The values obtained using H and M for areas without ligatures were 0.44 ± 0.15 and 0.47 ± 0.11 mm for lingual measurements and 0.23 ± 0.08 and 0.41 ± 0.10 mm for buccal measurements. No significant differences were found between the two methods in the detection of bone height associated with the placement of ligatures in rats.

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A Newly Noticed Formula Enforces Fundamental Limits on Geometric Morphometric Analyses

Evolutionary Biology ◽

10.1007/s11692-017-9424-9 ◽

2017 ◽

Vol 44 (4) ◽

pp. 522-541 ◽

Cited By ~ 24

Author(s):

Fred L. Bookstein

Keyword(s):

Geometric Morphometric ◽

Fundamental Limits ◽

Morphometric Analyses

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Morphological diversity in tenrecs (Afrosoricida, Tenrecidae): comparing tenrec skull diversity to their closest relatives

10.7287/peerj.preprints.811v1 ◽

2015 ◽

Author(s):

Sive Finlay ◽

Natalie Cooper

Keyword(s):

Quantitative Analysis ◽

Quantitative Methods ◽

Morphological Diversity ◽

Lateral View ◽

Ecological Niches ◽

Diverse Group ◽

Geometric Morphometric ◽

Skull Shape ◽

Morphometric Analyses ◽

The Family

Morphological diversity is often studied qualitatively. However, to truly understand the evolution of exceptional diversity, it is important to take a quantitative approach instead of relying on subjective, qualitative assessments. Here, we present a quantitative analysis of morphological diversity in a Family of small mammals, the tenrecs (Afrosoricida, Tenrecidae). Tenrecs are often cited as an example of an exceptionally morphologically diverse group. However, this assumption has not been tested quantitatively. We use geometric morphometric analyses of skull shape to test whether tenrecs are more morphologically diverse than their closest relatives, the golden moles (Afrosoricida, Chrysochloridae). Tenrecs occupy a wider range of ecological niches than golden moles so we predict that they will be more morphologically diverse. Contrary to our expectations, We find that tenrec skulls are only more morphologically diverse than golden moles when measured in lateral view. Furthermore, similarities among the species-rich Microgale tenrec Genus appear to mask higher morphological diversity in the rest of the Family. These results reveal new insights into the morphological diversity of tenrecs and highlight the importance of using quantitative methods to test qualitative assumptions about patterns of morphological diversity.

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On the morphospace of eurypterine sea scorpions

Earth and Environmental Science Transactions of the Royal Society of Edinburgh ◽

10.1017/s175569102100030x ◽

2021 ◽

pp. 1-6

Author(s):

Russell D. C. BICKNELL ◽

Lisa AMATI

Keyword(s):

New Taxa ◽

Compound Eye ◽

Developmental Changes ◽

Apex Predators ◽

Geometric Morphometric ◽

Eye Morphology ◽

Morphometric Analyses ◽

Ontogenetic Trajectories ◽

Landmark Analyses ◽

Shape Data

ABSTRACT Eurypterids (sea scorpions) are a group of extinct, marine euchelicerates that have an extensive Palaeozoic record. Despite lacking a biomineralised exoskeleton, eurypterids are abundantly preserved within select deposits. These collections make statistical analyses comparing the morphology of different genera possible. However, eurypterid shape has not yet been documented with modern geometric morphometric tools. Here, we summarise the previous statistical assessments of eurypterid morphology and expand this research by presenting landmark and semi-landmark analyses of 115 eurypterid specimens within the suborder Eurypterina. We illustrate that lateral compound eye morphology and position drives specimen placement in morphospace and separates proposed apex predators from more generalist forms. Additionally, evidence for size clusters in Eurypterus that may reflect ontogeny is uncovered. We highlight the use of geometric morphometric analyses in supporting the naming of new taxa and demonstrate that these shape data represent a novel means of understanding inter-generic ontogenetic trajectories and uncovering developmental changes within the diverse euarthropod group.

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Geometric Morphometric Analyses Support Incorporating the Goshen Point Type into Plainview

American Antiquity ◽

10.1017/aaq.2019.89 ◽

2019 ◽

Vol 85 (1) ◽

pp. 171-181 ◽

Cited By ~ 1

Author(s):

Briggs Buchanan ◽

Mark Collard ◽

Michael J. O'Brien

Keyword(s):

Recent Work ◽

Social Dynamics ◽

Spatiotemporal Variation ◽

Single Type ◽

Geometric Morphometric ◽

Morphometric Analyses ◽

Morphometric Methods ◽

Point Type

Recent work has demonstrated that Goshen points overlap in time with another group of unfluted lanceolate points from the Plains, Plainview points. This has raised the question of whether the two types should be kept separate or consolidated into a single type. We sought to resolve this issue by applying geometric morphometric methods to a sample of points from well-documented Goshen and Plainview assemblages. We found that their shapes were statistically indistinguishable, which indicates that Goshen and Plainview points should be assigned to the same type. Because Plainview points were recognized before Goshen points, it is the latter type name that should be dropped. Sinking Goshen into Plainview allows us to move beyond taxonomic issues and toward understanding both the spatiotemporal variation that exists among Plainview assemblages and what it can tell us about the adaptations and social dynamics of Plainview groups.

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Do island populations differ in size and shape compared to mainland counterparts?

Journal of Mammalogy ◽

10.1093/jmammal/gyz193 ◽

2019 ◽

Vol 101 (2) ◽

pp. 373-385 ◽

Cited By ~ 2

Author(s):

Sergio Ticul Álvarez-Castañeda ◽

Laura A Nájera-Cortazar

Keyword(s):

Geometric Morphometric ◽

Island Populations ◽

Terrestrial Vertebrates ◽

Skull Shape ◽

Skull Size ◽

Morphometric Analyses ◽

Interpopulation Variation ◽

Pocket Mouse ◽

Shape Analyses ◽

Insular Populations

Abstract Adaptation and evolution of terrestrial vertebrates inhabiting islands have been the topic of many studies, particularly those seeking to identify trends or patterns in body size in mammals, albeit not necessarily in shape, in relation to mainland populations. The spiny pocket mouse, Chaetodipus spinatus, is distributed in the Baja California peninsula and its surrounding islands. Insular populations became isolated ~12,000 due to changes in sea level; these populations’ matrilinear (mitochondrial) DNA shows minor interpopulation variation. We tested the hypothesis that adaptation and evolution in these island populations involve variation in both skull size and skull shape (using geometric morphometrics) relative to mainland populations, rather than only in size as previously assumed. A total of 363 specimens from 15 insular and peninsular populations were used in analysis of the skull length and geometric morphometric analyses. Our findings revealed significant differences related to skull size among population. The skull shape analyses showed two significantly different morphotypes: one for all island specimens and one for all mainland samples. Our analyses support the hypothesis that insular populations may not only vary in size relative to mainland populations, but may also show variations in shape, regardless of differing conditions across islands.

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