Enamel formation and growth in non-mammalian cynodonts

The early evolution of mammals is associated with the linked evolutionary origin of diphyodont tooth replacement, rapid juvenile growth and determinate adult growth. However, specific relationships among these characters during non-mammalian cynodont evolution require further exploration. Here, polarized light microscopy revealed incremental lines, resembling daily laminations of extant mammals, in histological sections of enamel in eight non-mammalian cynodont species. In the more basal non-probainognathian group, enamel extends extremely rapidly from cusp to cervix. By contrast, the enamel of mammaliamorphs is gradually accreted, with slow rates of crown extension, more typical of the majority of non-hypsodont crown mammals. These results are consistent with the reduction in dental replacement rate across the non-mammalian cynodont lineage, with greater rates of crown extension required in most non-probainognathians, and slower crown extension rates permitted in mammaliamorphs, which have reduced patterns of dental replacement in comparison with many non-probainognathians. The evolution of mammal-like growth patterns, with faster juvenile growth and more abruptly terminating adult growth, is linked with this reduction in dental replacement rates and may provide an additional explanation for the observed pattern in enamel growth rates. It is possible that the reduction in enamel extension rates in mammaliamorphs reflects an underlying reduction in skeletal growth rates at the time of postcanine formation, due to a more abruptly terminating pattern of adult growth in these more mammal-like, crownward species.

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The evolution of growth patterns in mammalian versus nonmammalian cynodonts

Paleobiology ◽

10.1017/pab.2015.51 ◽

2016 ◽

Vol 42 (3) ◽

pp. 439-464 ◽

Cited By ~ 15

Author(s):

Rachel N. O’Meara ◽

Robert J. Asher

Keyword(s):

Function Analysis ◽

Growth Patterns ◽

Adult Size ◽

Juvenile Growth ◽

Evolutionary Transitions ◽

Fossil Species ◽

Adult Growth ◽

Distribution Shape ◽

Gradual Evolution

AbstractOne of the major evolutionary transitions of the mammaliaform lineage was the origin of a typically mammalian pattern of growth. This is characterized by rapid juvenile growth followed by abrupt cessation of growth at adult size and may be linked with other important mammaliaform apomorphies of dental replacement and morphology. Investigation of growth patterns in the tritylodontid cynodont Oligokyphus and the basal mammaliaform Morganucodon provides insight into this crucial transition. We collected mandibular depth measurements from large samples of Morganucodon and Oligokyphus and constructed distributions of mandibular depth versus frequency for each species. These were compared with distributions from species from three different growth classes of extant amniote: testudines + crocodilians, mammals + birds, and lepidosaurs. Discriminant function analysis was used to differentiate between known growth classes by using different combinations of three measures of mandibular depth distribution shape (skew, kurtosis, and coefficient of variation) as proxies for different juvenile and adult growth patterns. Classification of the fossil species showed that Morganucodon closely resembled extant placental mammals in having rapid juvenile growth followed by truncated, determinate adult growth. Oligokyphus showed intermediate growth patterns, with more extended adult growth patterns than Morganucodon and slightly slower juvenile growth. This suggests a gradual evolution of mammalian growth patterns across the cynodont to mammaliaform transition, possibly with the origin of rapid juvenile growth preceding that of truncated, determinate adult growth. In turn, acquisition of both these aspects of mammalian growth was likely necessary for the evolution of diphyodont tooth replacement in the mammaliaform lineage.

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Microstructural growth patterns in the otoliths of larval and juvenile starry flounder, Platichthys stellatus

Canadian Journal of Zoology ◽

10.1139/z84-219 ◽

1984 ◽

Vol 62 (8) ◽

pp. 1507-1512 ◽

Cited By ~ 57

Author(s):

Steven E. Campana

Keyword(s):

Growth Rates ◽

Larval Growth ◽

Light And Electron Microscopy ◽

Growth Patterns ◽

Curvilinear Relationship ◽

Juvenile Growth ◽

Increment Width ◽

Fish Size ◽

Growth Increments ◽

Platichthys Stellatus

Microstructural growth patterns were examined and interpreted in the otoliths of both wild and laboratory-reared starry flounders, Platichthys stellatus. Growth increments were not formed with a daily periodicity in laboratory-reared larvae. However, increment counts increased with the degree of sample preparation, suggesting that increments near the resolving limit of light microscopy were not being observed. Increments in wild flounder sagittae were more clearly defined under both light and electron microscopy; in addition, larval and juvenile growth patterns could be easily differentiated. A transition zone between the growth regions corresponded to the size and age at metamorphosis. An increase of increment width with larval age resulted from a curvilinear relationship between otolith diameter and fish size. Larval growth rates of wild fish remained relatively constant at 0.25 mm/day until metamorphosis; juvenile growth rates were substantially higher. Metamorphosis was characterized by a sudden but temporary decline in growth rate.

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Early Growth of Magpie Geese, Anseranas-Semipalmata - Sex-Differences and Influence of Egg Size

Australian Journal of Zoology ◽

10.1071/zo9900249 ◽

1990 ◽

Vol 38 (3) ◽

pp. 249 ◽

Cited By ~ 8

Author(s):

PJ Whitehead ◽

WJ Freeland ◽

K Tschirner

Keyword(s):

Sex Differences ◽

Growth Rates ◽

Egg Size ◽

Growth Patterns ◽

Juvenile Growth ◽

Seasonal Wetlands ◽

Adult Body ◽

Wing Growth ◽

Juvenile Males ◽

Polygynous Mating System

The magpie goose, Anseranas semipalmata, is the most conspicuous and among the most numerous of waterfowl inhabiting the seasonal wetlands of tropical northern Australia. Modelling of juvenile growth rates of captive birds with the logistic equation showed that magpie geese grow at rates similar to the fast-growing anserine geese. High juvenile growth rates permit exploitation of seasonally favourable environments that, although highly productive, may deteriorate rapidly and unpredictably. Sex differences in juvenile growth patterns are consistent with pronounced sexual dimorphism in adult body size (larger males), which is associated with an unusual polygynous mating system. Although smaller, females grow relatively faster than males, so that at a given age they have completed a greater proportion of the pre-fledging growth phase; wing growth is particularly advanced and females fly earlier. Slower development may increase mortality among juvenile males when family groups are forced to abandon drying swamps, and contribute to skewing of the sex ratio towards females. Larger hatchlings from large eggs tend to maintain a size advantage, at least until fledging.

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Erratum: Corrigendum: Dinosaurian growth patterns and rapid avian growth rates

Nature ◽

10.1038/nature16488 ◽

2015 ◽

Vol 531 (7595) ◽

pp. 538-538

Author(s):

Gregory M. Erickson ◽

Kristina Curry Rogers ◽

Scott A. Yerby

Keyword(s):

Growth Rates ◽

Growth Patterns

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Growth and body weight of free-range reindeer in western Alaska

Rangifer ◽

10.7557/2.20.4.1517 ◽

2000 ◽

Vol 20 (2-3) ◽

pp. 221 ◽

Cited By ~ 7

Author(s):

Greg L. Finstad ◽

Alexander K. Prichard

Keyword(s):

Body Weight ◽

Growth Rates ◽

Total Body Weight ◽

Growth Patterns ◽

Spatial And Temporal Variation ◽

Adult Males ◽

Body Weights ◽

Total Body ◽

Reproductive Females ◽

Average Body

Total body weight of 9749 reindeer calves and 4798 adult reindeer were measured from 1984 to 1999 on the Seward Peninsula, western Alaska, USA. Growth rates of male and female calves, and annual growth patterns of adults were determined. Male calves grew faster than female calves. Reproductive females were lighter than non-reproductive females during summer but there was no effect of reproduction on average body weights the following winter. Adult males age 3-5 were heavier during summer than winter. Castrated males weighed the same as uncastrated males in summer, but were significantly heavier in winter, and did not display the large annual fluctuations in weight typical of reproductive males and females. Growth rates were higher and body weights greater in this herd than many other cir-cumpolar reindeer populations. We suggest these kinds of physiological indices should be used to monitor the possible effects of spatial and temporal variation in population density and to evaluate changes in herding practices.

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Seasonal patterns of pasture production in the Bay of Plenty and Waikato

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1991.53.2007 ◽

1991 ◽

pp. 67-72

Author(s):

J.A. Baars ◽

G.J. Goold ◽

M.F. Hawke ◽

P.J. Kilgarriff ◽

M.D. Rolm

Keyword(s):

Growth Rates ◽

Early Spring ◽

Early Summer ◽

Growth Patterns ◽

Climatic Data ◽

Large Contribution ◽

Pasture Production ◽

Summer Peak ◽

The Difference

Patterns of pasture growth were measured on 3 farms in the Bay of Plenty (BOP) and at No2 Dairy (Ruakura Agricultural Centre) in the Waikato from 1989 to 199 1. A standardised trim technique with cages and 4-weekly cutting under grazing was used. Long-term seasonal growth patterns, using a predictive pasture model, were also simulated. Simulated pasture growth from long-term climatic data shows that pasture growth rates are higher in winter, early spring and late autumn in the BOP than the Waikato. However, the actual measurements over the 2 years show that pasture growth over the latter periods is lower at the BOP sites than at the Waikato site. In the BOP the spring peak is much later than in the Waikato while an early summer peak, with higher growth rates than in the Waikato, occurred in the BOP. No such summer peak was evident in the Waikato. The difference between the two regions is caused by the large contribution of subtropical grasses to sward production in summer and autumn, The prolific summer growth of subtropical grasses may explain the low ryegrass content and low pasture production in winter. The lower than expected autumn, winter, spring production may also becaused by low clover content, possibly a result of competition from subtropical grasses and a sulphur deficiency. The apparent low amount of nitrogen fixed by clover may explain the low rates of pasture production over the cooler season. Applications of nitrogen fertiliser may substantially increase dry matter production from April to September. Keywords pasture,simulation,subtropical grasses, Paspalum, Digitaria sanguinalis, growth rates

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Abstract 13513: Serial CT Surveillance of Abdominal Aortic Aneurysm Diameter Demonstrates Predominantly Linear Growth (N-TA 3 CT)

Circulation ◽

10.1161/circ.142.suppl_3.13513 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Sydney Olson ◽

Marniker Wijesinha ◽

Annalise Panthofer ◽

William Blackwelder ◽

Gilbert R Upchurch ◽

...

Keyword(s):

Growth Rate ◽

Growth Rates ◽

Linear Growth ◽

Growth Patterns ◽

Aortic Aneurysms ◽

Transverse Diameter ◽

Invasive Treatment ◽

Abdominal Aortic ◽

Risk Of Rupture ◽

Serial Ct

Objective: Small abdominal aortic aneurysms (AAAs) have a low risk of rupture. Intervention is indicated when diameters exceed established thresholds. This study assessed the growth rates and patterns of AAAs over 2 years as documented on serial CT scans from the Non-Invasive Treatment of AAA Clinical Trial. Methods: 254 patients, 35 females with baseline AAA maximum transverse diameter (MTD) between 3.5-4.5 cm and 219 males with baseline MTD 3.5-5.0 cm, were included in this study. Linear regressions and segmental growth rates were used to model growth rates and patterns. Results: The yearly growth rates of AAA MTDs had a median of 0.17 cm/yr and mean of 0.19 cm/yr ± 0.14 (Figure 1). 10% of AAA displayed minimal to no growth (< 0.05 cm/yr), 62% low growth (0.05-0.25 cm/yr), 28% high growth (> 0.25 cm/yr). Baseline AAA diameter accounted for only 5.4% of growth rate variance (P<0.001, R 2 0.05). Most AAAs displayed linear growth (70%); large variations in interval growth rates occurred infrequently (3% staccato growth, 4% exponential growth); a minority of subjects’ growth patterns were not clearly classifiable (11% indeterminate-not growing, 12% indeterminate-growing) (Figure 2). No patients with baseline MTD < 4.25 cm exceeded sex-specific repair thresholds (males 0 / 92, [95% CI, 0.00-0.06]; females 0 / 25 [95% CI, 0.00-0.25]) in the course of follow-up for as long as two years. Conclusions: The majority of small AAAs exhibit linear growth; large intra-patient growth rate variations were infrequently observed over 2 years. AAA < 4.25 cm can be followed with a CT scan in 2 years with little chance of exceeding interventional MTD thresholds of 5.5 cm for men.

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Health, growth and development of pre-school children in Newcastle upon Tyne

Journal of Biosocial Science ◽

10.1017/s0021932000012499 ◽

1979 ◽

Vol 11 (4) ◽

pp. 411-424

Author(s):

H. Mary Fellowes ◽

Catherine A. Hytten ◽

W.Z. Billewicz ◽

A.M. Thomson

Keyword(s):

Growth Rates ◽

Seasonal Changes ◽

Growth Patterns ◽

Transient Effect ◽

Normal Children ◽

Average Growth ◽

Respiratory Illnesses ◽

Developmental Test ◽

One Year ◽

Newcastle Upon Tyne

SummaryOne hunderd and forty 'normal' children aged 0—5 years, selected from three large general medical practices to represent a wide socioeconomic range, were seen monthly for periods of at least one year. Average growth patterns, previously shown to be related to the energy value of diets, conformed to British standards. Height and weight were not significantly related to socioeconomic status, maternal 'efficiency', number of sibs nor place in family. About half the children aged 0.5 years or less changed growht 'channels', falling to 0.4% in children aged 2 years or more. Respiratory illnesses showed seasonal changes, but growth rates did not, and there was no evidence that illness of any kind or severity had more than a transient effect on growth rates. Developmental test scores were not found to be related to growth rates. Girls tended to have higher scores than boys. Children from non-manual families and those with sїbs at least 5 years older scored more highly in tests of language than those in other types of family.

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Factors influencing growth of juvenile spruce grouse

Canadian Journal of Zoology ◽

10.1139/z81-245 ◽

1981 ◽

Vol 59 (9) ◽

pp. 1790-1795 ◽

Cited By ~ 3

Author(s):

Norman W. S. Quinn ◽

Daniel M. Keppie

Keyword(s):

Growth Rate ◽

Body Weight ◽

New Brunswick ◽

Growth Rates ◽

Egg Laying ◽

Maternal Influence ◽

Juvenile Growth ◽

Factors Influencing ◽

Differential Timing

The influences of date of hatch, and age and prelaying body weight of brood female on the growth rate of juvenile spruce grouse (Canachites canadensis) were studied in central New Brunswick in 1977 and 1978. Because of differential timing of hatch of broods of adult and yearling females, it was not clear whether a difference in juvenile growth rates during 5–14 days of age in 1977 was related to date of hatch, age of brood female, or both. Differences in juvenile growth rates within and between years apparently were not influenced by body weight of brood females prior to egg laying. Results suggest that posthatch factors are more important in determining growth rate than a prehatch or "maternal" influence.

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Formation of wide-blocky calcite veins by extreme growth competition

Journal of the Geological Society ◽

10.1144/jgs2020-104 ◽

2020 ◽

pp. jgs2020-104

Author(s):

Liene Spruženiece ◽

Michael Späth ◽

Janos L. Urai ◽

Estibalitz Ukar ◽

Michael Selzer ◽

...

Keyword(s):

High Resolution ◽

Growth Rates ◽

Polarized Light ◽

Wall Rock ◽

Scattered Electron ◽

Thin Sections ◽

Content Type ◽

Calcite Veins ◽

Supplementary Material ◽

Electron Back Scattered Diffraction

Liassic limestones on the coast of Somerset in the UK contain dense arrays of calcite microveins with a common, but poorly understood microstructure, characterized by laterally wide crystals that form bridges across the vein. We investigated the mechanisms of formation and evolution of these ‘wide-blocky’ vein microstructures using a combination of high-resolution analytical methods, including virtual petrography, optical cathodoluminescence and scanning electron microscopy techniques (e.g. energy-dispersive X-ray spectrometry, back-scattered electron imaging, cathodoluminescence and electron back-scattered diffraction), laboratory experiments and multiphase field modelling. Our results indicate that the studied veins formed in open, fluid-filled fractures, each in a single opening and sealing episode. As shown by the optical and electron back-scattered diffraction images, the vein crystals grew epitaxially on grains of the wall rock and we hypothesize that their growth rates differed depending on whether the crystals were on a wall rock grain substrate that fractured intergranularly (slow growth rates) or transgranularly (rapid growth rates). Our multiphase field models support this hypothesis, showing that wide, blocky crystals only form where there are significant differences in the growth rate and are dependent on the type of seed grain. These results provide strong evidence for extreme growth competition, a process that we propose controls vein-filling in many micritic carbonate reservoirs, as well as demonstrate that the characteristics of the fracture wall can affect the filling processes in syntaxial veins.Supplementary material: The description and images of the studied thin sections are available at https://doi.org/10.6084/m9.figshare.c.5172371. High-resolution optical microscopy mosaics (under plane-polarized- and crossed polarized light) of the thin section collection in PetroScan file format are available on request from the authors.

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