Micropaleontology - Science topic

Dear Michael,

Concerning your photo #B533_5: I wouldn't rule out a dinoflagellate cyst Thalassiphora pelagica.

Best regards,

Alina

Thank you very much for your help!

It seems more and more likely, that the structures acutally might be eggs.

Reverse image search did not produce any helpful output unfortunatley.

It´s indeed a beautiful area, yes! - I will keep you updated in case I find out more!

In the photos you attach, I can see three specimens of planktic forams but you need to provide us with more clear and close photos to allow us to identify it. by the way i think the forams in the last photo is belong to Brizalina not Bolivina?? and you have to give him a double check.

Thanks for your answer Dr. Matos Pupo. Before the timescale of French archives, I used other scientific works published around my study site to find other hypotheses of sedimentological imprints of past storms. If these are several works were made in Cuba or around (Maybe Florida, Bahamas, Hispaniola), you can identify possible marine layers in the core studied and presented in other papers to propose connections with yours. If there is no other study, you can propose a new hypothesis never discovered until now. Regarding their thickness, it depends on the number of datings made, the age depth model and the sediment composition/homogeneity, but i think that I can largely differ between events.

Greetings,

Pierre

It is look like Alveolina sp.

Yes, I am working with peat cores and I count up to 400 valves for layer

Best regards

Maria

With an example: in Agnini et al 2014, the LAD of Discoaster lodoensis was calibrated at 48.37Ma on the 1995 GPTS. It is thus between the bottom of C21n (47.906Ma) and the top of C22n (49.037Ma). On the 2020 GPTS, those chron boundaries are at 47.760 and 48.878Ma respectively. The mapped age of the LAD of Discoaster lodoensis on the 2020 GPTS is thus (by linear interpolation): 47.760 + (48.37-47.906)*(47.906-47.760)/(49.037-48.878) = 48.18606Ma. Note that we normally have a page on the NSB website allowing this kind of conversion but it is currently buggy since we updated the website last month and i m currently busy correcting it to allow this type of conversions again).

Thank you very much Obianuju ! I had the same problem, which is solved now.

Yes, these microfossils look like calcispheres.

Dear Hesam it is bryozoan fragment

It resembles most likely bryozoan (or possibly some encrusting organisms...).

Best

First of all check whether these could be echinodermal pieces! Each echinodermal piece behaves like a single crystal and turns out black in one goal with cross-polars on when rotating the microscope stage. Because a single Saccocomid animal is made of numerous pieces you should have a lot of them in a single thin section, not few of them.

Obviously your material does not comprise any calpionellid!

Dear Alvaro , I think it is calcisphers-sponge spicules wackestone to packstone microfacies which common in toe of slope environment.

Kind regards.

Irfan

Dear Šoster,

If the limestone is not hard and compacted (later case need thin sectioning), you can try to use boiling water and adding hydrogen pyroxide with a continuous stirrer for at least 72 hours (best for chalky and marly limestone). This method leads to getting better and clean tests usually. If they still coagulate, you can add, but be careful, very very little amount (one drop or two) of diluted sodium hydroxide (the later dissolved calcareous tests and etching siliceous tests).

Dear Toyin, use boiling water and hydrogen pyroxide for at least 72 hours with stirring give much better, clean residue chalky limestone, marly limestone, and shale.

Good Luck

Hi, it does not make much sense to name such biosedimentary microbial structures at a specific level (hence at the generic level). Would you give generic or specific names to stromatolitic structures? The tubes do not show any parting and they are bifurcating with an acute angle. It would be smart to call them "cayeuxia structures" (not Cayeuxia algae). =)

Dear Majed,

This paper may be of interest to you:

Vavrek MJ. 2016. A comparison of clustering methods for biogeography with fossil datasets. PeerJ 4:e1720 https://doi.org/10.7717/peerj.1720

It concerns biogeographic data but its conclusions are interesting for fossil datasets.

All the best.

These specimens can safely be placed under Lejeunecysta sp. For identification of species specimens will have to be examined under microscope.

Dear Mr. Nejad,

your attempt to interpret the carbonate (micro) facies is very ambitious and is in my opinion not the correct way because the term facies is a far-reaching one to discuss the origin of a rock unit, in this case a sedimentary one where all available features of different scales need to be considered. The late Professor Walliser from Göttingen University once showed us a hand specimen and said: “ You should not create a new orogeny using only one hand specimen”. With kind regards H.G.Dill

No oolite at all, but calcispheres (= calciodinoflagellate cysts) -@ Som Nath Kundal -

Hi Patrick,

nice! Many thanks for you very detailed list of references. I will go through them in order to find more on upper K forams.

Best,

Lorenzo

Dear Robert

I guess so. You are right Thank you for your comment.

Could some of the more crumpled specimens, like the second from the left on the bottom, be Leoisphaeridia? I have similar looking problematic palynomorphs that are folded, spherical, with no ornamentation or aperture. Sometimes things get so folded I don't know what they are.

Siddhartha:

Your question embraces broad spectrum of shallow marine environments, but this classic link would provide you essential insights:

Best

Syed

Cameron:

Your guess seems right, as the forms may belong to Hedbergellidae. Kindly see this link for insights:

Best

Syed

 Thank you so much   Dr.  Hakima Belkhattab  for your  input.

 Regards

 Sanjay

Dear Amr Zaky.

In spite of low resolution, but the image is clear where the last chamber is inflated. It may be hypotype of Gaudryina laevigata. Be sure it is distributed in many samples and in notable number, to be defined as new var. of Gaudryina laevigata.  best regard

the first picture,s probably is microbal trace and second,s probably is coral fossil remained.

Hi Polla,

Your specimen might be a Spinaxon potyi sp.

Kind regards

Hakima

Dear Prof. Cesare Andrea Papazzoni,

Thank you for your interest. Now, I am preparing axial and equatorial sections of the specified species. After getting more detailed photos of it, i will contact with you for more cooperation.

Amr 

Eugen:

What about Late Palaeozoic Argilloecia regularis Delo, 1930? What's your opinion?

Best

Syed

Due to number 3 & 4 

Family: Spondylidae Gray, 1826,Genus: Spondylus Linnaeus, 1758, most of can be Clypeaster intermedius

Dear Asghar

send your images to my E-mail: jaser.khosroabadi@gmail .com

Hi Zhang,

Fig.9 looks like Leguminocythereis sorneana

All the best

You might be interested in the very last contribution of Guex and Galster

"A simple technique to establish sequences of datums and to highlight transgressive–regressive cycles"

Hello João,

Picture 1 makes me think of a non-pollen palinomorph (NPP) and I agree with Reza that picture 6 is an Asteraceae pollen grain.

For the diatoms, picture 5 seems to me like a Amphora valves in girdle view. While pictures 7 and 8 could be a Mastogloia genus. However, pictures 9 and 10 looks like a Rhopalodia, maybe a Rhopalodia gibberula?

Hi Celestine,

Your second photo: this is pollen grain.

Thanks for comments, interesting, approach you shortly.

Looks a Miogypsina....preservation is not suitable for accurate species identification

Hello Damien,

Unfortunately, there are not many useful Recent review papers ... However, the paper by Vorob'eva et al., published half a year ago, shows a lot of different (Mesoproterozoic) acritarch types ... Best wishes, Mike

Vorob'eva, N.G.; Sergeev, V.N. & Petrov, P.Y. (2015): Kotuikan Formation assemblage: A diverse organic-walled microbiota in the Mesoproterozoic Anabar succession, northern Siberia. Precambrian Research 256: 201-222.

Hello Mr. Papazzoni,

I just checked the link and it is now active, please go check it out.

Dear Navnith,

Your micro-photo is of a very poor quality. Nevertheless,  it can not be Asterionella by any means due to the central structure of pentagon (sometimes observed) and elongated spikes, which may sometimes be found in silicoflagellates - Dictyochophyceae. Moreover, Asterionella is a diatom freshwater planktonic genus while silicoflagelaltes are typically marine plankton species. I am attaching two related photos just for comparison, since my filed is not the marine but freshwater environment. 

Best wishes for your work. 

I suggest that you visit the Geoscience e-Journals' portal at http://paleopolis.rediris.es/geosciences/

There is a good chance you find an Open Access journal to publish in; there are more than 60 journals ... they do not necessarily deal with micropaleontology: you need to dig in the list!

Dear Tarun

It is necessary to note that radiolarians capture and digest a large variety of small prays (e.g. silicoflagellates, ciliates, tintinnids, diatoms, crustacean larvae, copepods and bacteria). This is done by use of their “sticky” pseudopodia (in particular the axopodia and/or rhizopodia). Several different feeding strategies have been reported for radiolarians (Anderson 1983; Matsuoka 2007). The captured food is enclosed in a digestive vacuole and carried into the ectoplasm where the digestion occurs. Although many radiolarian species are assumed to be omnivores, some feeding preferences do exist. There are, for instance, species preferring algal- before animal prey and vise versa (Anderson 1983). Some radiolarians are not actively hunting their food, but live primarily of nutrients obtained from their symbiotic photosynthesizing algae.

some link that useful for your question

Hi Antonio, I'd like to see them

Dear Alexandre

based on Gallego et al. (2013) and Arai and Souza Carvalho (2001), just Cyzicus pricei Cardoso was described by microalveolar ornomentation.

Regards

Massih

Can you upload the image of higher size?

In warm seas diatoms may not survive during diagenesis - I've never encountered diatoms in my own Paleogene material. However, I note in your paper, that your smallest size fraction is 0.2 mm. This is too large for all but perhaps the largest diatoms. Also for foraminiferal studies you should better use smaller size fractions, at least 125 microns or better even (when preservation permits) 63 micron. The diversity of your assemblages will increase significantly. Absence of planktic forams is no surprise in a very shallow environment, but you may find them also in the smaller size fraction, possibly washed in from the open sea.

Hi Praveen,

Stiller et al. (1985) is a good classical example for an evaporitic system.

Both, 18O and 13C of the precipitated CaCO3 depend on the isotope composition of the dissolved carbonate group. Degassing of CO2 from supersaturated aqueous solution leads to the enrichment of 13C in residual DIC. Therefore, since both the distribution of 13C and 18O of the individual dissolved inorganic carbon species depend on pH (e.g., Beck et al., 2005) it will also vary with biological activity, salt contents (e.g., ion pairs-look on the original experimental literature from the 60s and 70s)  and most likely precipitation rate. Biological activity may, therefore, also impact the signal via pH or kinetic effetcs as well as later recrystallization reactions.

Good luck, Michael

Dear Monika,

Because your question was formulated: “Middle Triassic calcispheres?” I answered in this connection. On closer examination of attached photos, I turned my attention to the pictures 4 and 7. They resemble the sections of the species Gemeridella minuta Borza & Misik. I hope that for you in this case could be useful following articles:

1. Borza, K., Misik, M. 1975. Gemeridella minuta n. gen., n. sp. aus der oberen Trias der Westkarpaten. Geol. Zb., 26; 77-81.

2. Misik, M., Borza, K., 1978. Gemeridella, Didemnoides, Didemnum und Korperchen ahnlicher Gestalt aus dem Mesozoikum der Westkarpaten. Geol. Zb.– Geologica Carpathica, 29; 307–326.

Good luck!

Daria

Even if spherical objects are quite common in the fossil record, these look very intruiging to me. I have, together with my colluege Mats Eriksson, done some work on spherical things we thought were Cambrian embryos. We used the micro tomography facility, TOMCAT, at the Swiss Light Source (SLS) in Switzerland. This non-destructive method is a brilliant help in deciphering the internal structures of fossil material. The data set consists of 100-2000 tiff images (i.e digital thin sections) that is combined in a 3D-program ( I am using Voxler3), whereafter you can detect morphologic features down to about 1 micron and spot internal structures in situ in great detail. If you are interested in having a go on this, we can run a few of your spheres the next time me or Mats have beam time at SLS. Interested?

Cheers,

Fredrik

Hello!

I've seen quite a few papers on this topic on the Olexandr Kovalchuk's page.

You can have a look at his ResearchGate profile and publications, and maybe contact him and see if he's interested:

Heliozoa too fragile for this, but maybe one of the testate amoebae. I've seen plenty of testate amoebae in amber. One should not exclude that it could be junk (non-biological).

thanks Johanenes for your opinion.

Sphaerogypsina in Loeblich & Tappan, 1987

Very similar structures occur in large numbers in e.g. the Lichtenberg Horizon of the ENCi quarry. These were described by Van Ameron 1973 as Coprolus maestrichtiensis, 

For cyanobacteria (phosphate deposit forming cyanobacteria) it is documented that it is their post mortem alteration...same is true for shelly deposits generating phosphatic deposits.....It may be the same phenomenon in case of conodonts added with replacement of calcium carbonate by calcium phosphate. It has also been published (in Nature) that apatite crystallites grow over organic carbon nucleites.  

Yes.But its usage really depends on what you are looking for.Species diversity analysis using dead forams are highly used in paleooceanographic studies to understand the variation in ocean currents resulting from changes in climate patterns.

You can extract microfossils and palynomorphs by treating the asphalt with kerosene for dilution , and then pass it through nylon mesh and pull the diluted asphalt or even crude oil by pipit and disseminate on slide, let the solution dry for overnight then use transmitted light microscopy to identify the particulate organic matter.

Yes Antonino is right. It is a fragment of Cuneolina which ranges from Valanginian to Maastrichtian.

Check my book:

BouDagher-Fadel, MK; (2008) Evolution and Geological Significance of Larger Benthic Foraminifera. Developments in Palaeontology and Stratigraphy: Vol.21. ELSEVIER

Diatom oozes belongs to deep pelagic sediments (more than 500 m depth) that are mostly characteristic for higher latitudes of oceans where diatoms deposits 2-10 mm/1000 years. Diatom oozes that are deposited in hemipelagial area (continental shelf, continental upwelling) where higher biogenic production of diatoms are more common and their accumulation in sediments as a pellets or marine snow could give diatomite or diatomaceous earth.

Age reversals are due to a low accuracy of an age date, although the date may have a high precision. They are therefore part of the noise in your data. Using an interpolation you make an arbitrary assumption about signal and noise in your chronology. I think you should carefully discuss possible reasons for the low accuracy and then remove the age date from the chronology.