File:Fossiliferous dolostone with ostracods 2.jpg
![File:Fossiliferous dolostone with ostracods 2.jpg](https://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Fossiliferous_dolostone_with_ostracods_2.jpg/800px-Fossiliferous_dolostone_with_ostracods_2.jpg?20231011154128)
Original file (2,997 × 1,798 pixels, file size: 3.21 MB, MIME type: image/jpeg)
Captions
Captions
Summary
[edit]DescriptionFossiliferous dolostone with ostracods 2.jpg |
English: Dolostone is a crystalline-textured chemical sedimentary rock composed of dolomite (CaMg(CO3)2 - calcium magnesium carbonate). Most dolostones form by chemical alteration of previously-existing limestones. They tend to be fine-grained, vuggy (= having irregularly-sized and irregularly-shaped holes), and have poorly preserved fossils.
The small ovoid fossils in this dolostone sample are ostracods, often jokingly called "lima beans". Ostracods have an Ordovician to Holocene fossil record. Some Cambrian fossils (e.g., bradoriids) were formerly assigned to ostracods. True ostracods are small crustaceans with a calcified, bivalved, hinged carapace ("shell"). Most are microfossil-sized, but some are much larger. Many forms have considerable sexual dimorphism - females can have a different shell form compared with males. Such adult female ostracods are called heteromorphs. The pre-adult ostracods and male adults are called tecnomorphs. Most ostracods are filter feeders, but some are detritus feeders. They principally consume diatoms (= tiny, 1-celled, photosynthesizing protists) and other small "algal"; forms. Marine, brackish, and freshwater ostracods are known - they can be benthic (on the seafloor) or nektonic (free-swimming). Even terrestrial ostracods are known, but they are rare - they live on water drops on leaves in some jungles. Ostracods occur in large numbers in aquatic settings, but they are not very good swimmers - they are virtually defenseless against fish. Ostracods are common fossils and have biostratigraphic utility. They are often used by petroleum companies to date sedimentary rocks. They are probably the most economically significant crustacean group. In Mesozoic and Cenozoic rocks, ostracods are second only to foraminifera in abundance and biostratigraphic importance. Ostracod shells often have prominent ornamentation, consisting of lobes, spines, and processes. The ornamentation is used for taxonomic differentiation. Paleozoic ostracods tend to have more ornamentation than later forms. Some ostracods are just smooth "lima beans". The hinge line is on the dorsal side of the shell and typically consists of a simple groove or edge. Interlocking teeth structures, as in bivalves or brachiopods, are not present. Generally, there are five pairs of adductor muscles, which are used to close the shell - their presence will leave muscle scars on the shell's interior. Ostracod shells usually have tiny holes through which sensory hairs extended. Transparent to translucent portions of the shell are where eyespots occur. Some ostracods have only one eyespot. Classification: Animalia, Arthropoda, Crustaca, Ostracoda Stratigraphy: unknown, but possibly from the Silurian of Ohio Locality: out-of-place sample from Pickerington, northwestern Fairfield County, central Ohio, USA See info. at: en.wikipedia.org/wiki/Ostracod |
Date | |
Source | https://www.flickr.com/photos/47445767@N05/53247329909/ |
Author | James St. John |
Licensing
[edit]![w:en:Creative Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/CC_some_rights_reserved.svg/90px-CC_some_rights_reserved.svg.png)
![attribution](https://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Cc-by_new_white.svg/24px-Cc-by_new_white.svg.png)
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
![]() |
This image was originally posted to Flickr by James St. John at https://flickr.com/photos/47445767@N05/53247329909. It was reviewed on 11 October 2023 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
11 October 2023
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 15:41, 11 October 2023 | ![]() | 2,997 × 1,798 (3.21 MB) | Ser Amantio di Nicolao (talk | contribs) | Uploaded a work by James St. John from https://www.flickr.com/photos/47445767@N05/53247329909/ with UploadWizard |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
Camera manufacturer | Canon |
---|---|
Camera model | Canon PowerShot D10 |
Exposure time | 1/400 sec (0.0025) |
F-number | f/3.2 |
ISO speed rating | 80 |
Date and time of data generation | 17:56, 9 October 2023 |
Lens focal length | 8.295 mm |
Width | 4,000 px |
Height | 3,000 px |
Bits per component |
|
Pixel composition | RGB |
Orientation | Normal |
Number of components | 3 |
Horizontal resolution | 180 dpi |
Vertical resolution | 180 dpi |
Software used | Adobe Photoshop Elements 20.0 (Macintosh) |
File change date and time | 19:38, 9 October 2023 |
Y and C positioning | Co-sited |
Exif version | 2.21 |
Date and time of digitizing | 17:56, 9 October 2023 |
Meaning of each component |
|
Image compression mode | 3 |
APEX shutter speed | 8.65625 |
APEX aperture | 3.34375 |
APEX exposure bias | −0.66666666666667 |
Maximum land aperture | 3.34375 APEX (f/3.19) |
Metering mode | Pattern |
Flash | Flash did not fire, compulsory flash suppression |
Supported Flashpix version | 1 |
Color space | sRGB |
Focal plane X resolution | 16,460.905349794 |
Focal plane Y resolution | 16,483.516483516 |
Focal plane resolution unit | inches |
Sensing method | One-chip color area sensor |
File source | Digital still camera |
Custom image processing | Normal process |
Exposure mode | Manual exposure |
White balance | Auto white balance |
Digital zoom ratio | 1 |
Scene capture type | Standard |
Lens used | 6.2-18.6 mm |
Date metadata was last modified | 15:38, 9 October 2023 |
Unique ID of original document | 80BFEAB93E1BD09FD68B06405C96DF11 |