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Bioerosion of Inorganic Hard Substrates in the Ordovician of Estonia (Baltica).

Vinn O, Wilson MA, Toom U - PLoS ONE (2015)

Bottom Line: Bioerosion is mostly associated with carbonate hardgrounds, but cobbles and pebbles broken from the hardgrounds are also often penetrated by Trypanites borings.The general diversity of boring ichnotaxa in Baltica increased from one ichnospecies in the Cambrian to seven by the end of Ordovician, showing the effect of the GOBE on bioeroding ichnotaxa.This difference can be explained by the wider environmental distribution of organic as compared to inorganic substrates in the Ordovician seas of Baltica, and their more continuous temporal availability, which may have caused increased specialization of several borers.

View Article: PubMed Central - PubMed

Affiliation: University of Tartu, Department of Geology, Tartu, Estonia.

ABSTRACT
The earliest bioeroded inorganic hard substrates in the Ordovician of Estonia appear in the Dapingian. Hardgrounds are also known from the Sandbian and Katian. Most of the bioerosion of inorganic hard substrates occurs as the boring Trypanites Mägdefrau, 1932 along with some possible Gastrochaenolites borings. North American hardground borings are more diverse than those in Baltica. In contrast to a worldwide trend of increasing boring intensity, the Estonian record seems to show no increase in boring intensities during the Middle and Late Ordovician. Hardgrounds seem to be more common during the temperate climate interval of the Ordovician calcite sea in Estonia (seven hardgrounds during 15 my) than in the part with a tropical climate (four hardgrounds during 12 my). Bioerosion is mostly associated with carbonate hardgrounds, but cobbles and pebbles broken from the hardgrounds are also often penetrated by Trypanites borings. The general diversity of boring ichnotaxa in Baltica increased from one ichnospecies in the Cambrian to seven by the end of Ordovician, showing the effect of the GOBE on bioeroding ichnotaxa. The diversity of inorganic hard substrate borers increased by only two times. This difference can be explained by the wider environmental distribution of organic as compared to inorganic substrates in the Ordovician seas of Baltica, and their more continuous temporal availability, which may have caused increased specialization of several borers. The inorganic substrates may have been bioreroded only by the generalists among boring organisms.

No MeSH data available.


Stratigraphy of Pakri cliff.Modified after Hints et al. (2008). Red-hardgrounds. Blue-cobbles and pebbles.
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pone.0134279.g002: Stratigraphy of Pakri cliff.Modified after Hints et al. (2008). Red-hardgrounds. Blue-cobbles and pebbles.

Mentions: The Pakri hardground is a surface in the middle of a sandy limestone within the Pakri Formation (Kunda Regional Stage, early Darriwilian) at Pakri Cliff, near Paldiski Town (Figs 1 and 2). This hardground is sparsely encrusted by bryozoans and echinoderms. No bioerosion has been reported [21].


Bioerosion of Inorganic Hard Substrates in the Ordovician of Estonia (Baltica).

Vinn O, Wilson MA, Toom U - PLoS ONE (2015)

Stratigraphy of Pakri cliff.Modified after Hints et al. (2008). Red-hardgrounds. Blue-cobbles and pebbles.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4517899&req=5

pone.0134279.g002: Stratigraphy of Pakri cliff.Modified after Hints et al. (2008). Red-hardgrounds. Blue-cobbles and pebbles.
Mentions: The Pakri hardground is a surface in the middle of a sandy limestone within the Pakri Formation (Kunda Regional Stage, early Darriwilian) at Pakri Cliff, near Paldiski Town (Figs 1 and 2). This hardground is sparsely encrusted by bryozoans and echinoderms. No bioerosion has been reported [21].

Bottom Line: Bioerosion is mostly associated with carbonate hardgrounds, but cobbles and pebbles broken from the hardgrounds are also often penetrated by Trypanites borings.The general diversity of boring ichnotaxa in Baltica increased from one ichnospecies in the Cambrian to seven by the end of Ordovician, showing the effect of the GOBE on bioeroding ichnotaxa.This difference can be explained by the wider environmental distribution of organic as compared to inorganic substrates in the Ordovician seas of Baltica, and their more continuous temporal availability, which may have caused increased specialization of several borers.

View Article: PubMed Central - PubMed

Affiliation: University of Tartu, Department of Geology, Tartu, Estonia.

ABSTRACT
The earliest bioeroded inorganic hard substrates in the Ordovician of Estonia appear in the Dapingian. Hardgrounds are also known from the Sandbian and Katian. Most of the bioerosion of inorganic hard substrates occurs as the boring Trypanites Mägdefrau, 1932 along with some possible Gastrochaenolites borings. North American hardground borings are more diverse than those in Baltica. In contrast to a worldwide trend of increasing boring intensity, the Estonian record seems to show no increase in boring intensities during the Middle and Late Ordovician. Hardgrounds seem to be more common during the temperate climate interval of the Ordovician calcite sea in Estonia (seven hardgrounds during 15 my) than in the part with a tropical climate (four hardgrounds during 12 my). Bioerosion is mostly associated with carbonate hardgrounds, but cobbles and pebbles broken from the hardgrounds are also often penetrated by Trypanites borings. The general diversity of boring ichnotaxa in Baltica increased from one ichnospecies in the Cambrian to seven by the end of Ordovician, showing the effect of the GOBE on bioeroding ichnotaxa. The diversity of inorganic hard substrate borers increased by only two times. This difference can be explained by the wider environmental distribution of organic as compared to inorganic substrates in the Ordovician seas of Baltica, and their more continuous temporal availability, which may have caused increased specialization of several borers. The inorganic substrates may have been bioreroded only by the generalists among boring organisms.

No MeSH data available.