scholarly journals Biological clocks and incremental growth line formation in dentine

2020 ◽  
Vol 237 (2) ◽  
pp. 367-378 ◽  
Author(s):  
Amanda M. Papakyrikos ◽  
Manish Arora ◽  
Christine Austin ◽  
Julia C. Boughner ◽  
Terence D. Capellini ◽  
...  
Keyword(s):  
Growth Line ◽  
Biological Clocks ◽  
Line Formation ◽  
Incremental Growth

The Composition of Tidally Deposited Growth Lines in the Shell of the Edible Cockle, Cerastoderma Edule

1985 ◽  
Vol 65 (3) ◽  
pp. 573-581 ◽  
Author(s):  
Margaret R. Deith
Keyword(s):  
Marine Invertebrates ◽  
Biological Clock ◽  
Growth Line ◽  
Line Formation ◽  
Cerastoderma Edule

The shells of marine invertebrates grow incrementally (Wilbur, 1972). When a section of shell is observed under the microscope, the increments are often visible, separated by fine lines (Fig. 1). Studies of these phenomena have focused chiefly on the periodicity of increment and growth-line formation, principally because of its geological or archaeological application as a ‘biological clock’ (e.g. Wells, 1963; Koike, 1973).

The shell as a recording device: growth record and shell ultrastructure of Lampsilis radiata radiata (Pelecypoda: Unionidae)

1984 ◽  
Vol 62 (12) ◽  
pp. 2495-2504 ◽  
Author(s):  
Margaret E. Day
Keyword(s):  
Shell Growth ◽  
Maximum Size ◽  
Growth Line ◽  
Scanning Electron Micrographs ◽  
Nacreous Layer ◽  
Recording Device ◽  
Line Formation ◽  
Thin Sections ◽  
Damage Response ◽  
Organic Matrices

Growth records retained in the shell of Lampsilis radiata radiata and shell ultrastructure were examined in a population from Lake Champlain, Vermont, U.S.A. Maximum size was 75 mm as measured from the umbo to the farthest margin. Ages were obtained by counting annual bands, and growth plots were constructed. By knowing the amount grown by individuals of the same age in the same year, the years 1975 and 1977 were identified as poor for growth of younger individuals. Light micrographs of shell thin sections showed macroscopic annual lines, and microscopic and ultrastructural lines. Ultrastructural lines were visible within macroscopic lines. Scanning electron micrographs of etched sections clarified the light micrographs and allowed recognition of two damage-response structures embedded within the nacreous layer in the umbonal region: adventitious conchiolin and prismatic crystals. Theories of growth line formation are presented. Shell growth appears to follow an alternating cycle of protein deposition as organic matrices followed by CaCO3 secretion into the matrices. The Lutz–Rhoads theory of growth line formation, based on alternating periods of aerobic and anaerobic metabolism, was examined in detail and found unsuitable for this species.

Anaerobiosis and a Theory of Growth Line Formation

Science ◽  
1977 ◽  
Vol 198 (4323) ◽  
pp. 1222-1227 ◽  
Author(s):  
R. A. Lutz ◽  
D. C. Rhoads
Keyword(s):  
Growth Line ◽  
Line Formation

Dental histology of mosasaurs and a marine crocodylian from the Campanian (Upper Cretaceous) of southern Sweden: incremental growth lines and dentine formation rates

2013 ◽  
Vol 151 (1) ◽  
pp. 134-143 ◽  
Author(s):  
JOHAN A. GREN ◽  
JOHAN LINDGREN
Keyword(s):  
Upper Cretaceous ◽  
Tooth Development ◽  
Dental Trauma ◽  
Growth Line ◽  
Daily Increments ◽  
Incremental Growth ◽  
Functional Dentition ◽  
Width Measurements ◽  
Extinct Group

AbstractMosasaurs are an extinct group of secondarily adapted aquatic lizards that became the dominant marine tetrapods in the Late Cretaceous oceans. They continuously shed and replaced their teeth in order to maintain a functional dentition at all times; however, the process of tooth development in mosasaurs is still incompletely known. Based on incremental line width measurements and growth line counts, we assess dentine formation rates in three mosasaur taxa (Dollosaurus, cf. Platecarpus and Tylosaurus) and one genus of marine crocodylian (Aigialosuchus), all from the lower Campanian (Upper Cretaceous) of southernmost Sweden. Two sets of periodic dentinal markings characterized by concentric, alternating opaque and transparent laminae are recognized: one set comprising thin bands situated 6–34 μm apart (depending on taxon), which is superimposed onto a second set of coarser bands where spaces vary between 102 and 275 μm. Assuming that the finer striations represent daily increments (i.e. lines of von Ebner), it is estimated that the deposition of dentine at the sectioned level of the tooth-crowns took 342 (cf. Platecarpus), 426 (Dollosaurus), 487 (Tylosaurus) and 259 (Aigialosuchus) days, respectively. The coarser bands contain between 11 and 13 thin striations each, and are thus considered to be homologous to similar periodic dentinal markings in extant vertebrates, i.e. Andresen lines. Prolonged tooth development times in large-toothed taxa, such as Tylosaurus, presumably increased the risk of long-term incapacity to capture prey after dental trauma, an evolutionary trade-off which may have been compensated for by allometric modifications of the teeth.

scholarly journals Tree-Ring Analysis of Intermediate Hawthorn (Crataegus media Bechst.) in NW Poland

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Anna Cedro ◽  
Bernard Cedro
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Agricultural Landscape ◽  
Positive Influence ◽  
Dominant Factor ◽  
Incremental Growth ◽  
High Precipitation ◽  
Ring Analysis ◽  
Uncultivated Land ◽  
Nw Poland

Intermediate hawthorn (Crataegus × media Bechst.) is broadly distributed in Europe but very rarely examined by dendrochronologists. In NW Poland, it is one of three naturally occurring hawthorn species, growing mainly at forest margins, along roads, in mid-field woodlots, and on uncultivated land. Biocenotically, it is a very valuable species. This study aimed to determine the age of trees, tree-ring dynamics, and growth–climate relationship for intermediate hawthorn. Signature years were also determined. Samples for analysis were collected from 22 trees growing in a typical agricultural landscape in a monospecific mid-field woodlot comprised of several hundred specimens of various ages and forms (shrubs and trees). Using classic methods of dendrochronological dating, a 40-year long chronology spanning 1981–2020 was constructed. The radial growth rate of intermediate hawthorn is comparable to other tree species forming stands in NW Poland and equals 2.41 mm/year. Considerable intersubject variability is noted, from 1.48 to 4.44 mm/year. The chronology was also used for dendroclimatological analyses, including correlation and response function and signature years. Of the meteorological parameters analyzed, annual incremental growth in hawthorn is the most strongly shaped by precipitation totals from May to August of the current vegetation year: high rainfall favors the formation of wide tree-rings. Statistically significant growth–climate relationships were also obtained for winter months (December of the preceding vegetation year, January and February), for which period negative correlation and regression values are noted for air temperature and insolation. Furthermore, high precipitation, low-temperature and low insolation late in the preceding vegetation year (especially in August) make a positive influence on the condition of trees in the upcoming growing season. Signature year analysis clearly pointed to precipitation as the dominant factor in shaping tree-rings in the studied hawthorn population. As there are no dendrochronological papers concerning indigenous hawthorn species, future studies should be expanded to include diverse geographic locations and habitat conditions and should include all three species of hawthorn occurring in Poland.

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