File:Helicoprion sp. (fossil shark tooth whorl) 2 (34210412012).jpg
![File:Helicoprion sp. (fossil shark tooth whorl) 2 (34210412012).jpg](https://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Helicoprion_sp._%28fossil_shark_tooth_whorl%29_2_%2834210412012%29.jpg/800px-Helicoprion_sp._%28fossil_shark_tooth_whorl%29_2_%2834210412012%29.jpg?20191206013257)
Original file (3,008 × 1,948 pixels, file size: 4.47 MB, MIME type: image/jpeg)
Captions
Captions
Summary
[edit]DescriptionHelicoprion sp. (fossil shark tooth whorl) 2 (34210412012).jpg |
Helicoprion sp. - fossil shark tooth whorl, probably from the Permian of Idaho, USA. (IMNH, Idaho Museum of Natural History, Idaho State University, Pocatello, Idaho, USA) Bluish areas = vivianite (Fe3(PO4)2·8H2O - hydrous iron phosphate) This remarkable fossil is a symphyseal tooth whorl from the lower jaw of an edestoid shark. Sharks have a cartilaginous skeleton and mineralized, phosphatic teeth (as are all vertebrate teeth). Helicoprion is undoubtedly the strangest shark in geologic history (see reconstructions elsewhere in this photo album and at the links given below). Some paleontologists have interpreted the tooth whorl of Helicoprion sharks as part of a externally coiled lower jaw that may have been whipped outward and back to capture fish prey. Although intriguing, this type of reconstruction is incorrect. Instead, the tooth whorl was internal (inside the lower jaw tissues), and occupied the entire length of the lower jaw. The latter interpretation is based on an Idaho specimen that has soft-part preservation. The spiral has been interpreted as a single tooth with numerous cusps. The oldest cusps are the smallest and occur at the center of the whorl. New, larger cusps were generated near the articulation joint between the shark's lower jaw (mandible) and the rest of the head. Helicoprion was an experiment in tooth retention - this shark could not eject teeth, unlike modern sharks. Helicoprion sharks had modern-style scales on the body surface. Such scales result in no ripples and no sound while swimming - useful features in a marine predator. The classic interpretation of this shark having an external, open whorl as its lower jaw defeats the no-ripples-no-sound advantage of modern-style shark scales. An open, external tooth whorl is not hydrodynamic. Classification: Animalia, Chordata, Vertebrata, Chondrichthyes, Elasmobranchii, Eugeneodontida, Edestoidea, Agassizodontidae/Helicoprionidae Thanks to Jesse Pruitt who provided info. and access to Helicoprion museum specimens. See info. at: <a href="http://web.uri.edu/celsnews/two-uri-biologists-solve-mystery-of-a-strange-ancient-shark/" rel="nofollow">web.uri.edu/celsnews/two-uri-biologists-solve-mystery-of-...</a> and <a href="http://rsbl.royalsocietypublishing.org/content/9/2/20130057" rel="nofollow">rsbl.royalsocietypublishing.org/content/9/2/20130057</a> |
Date | |
Source | Helicoprion sp. (fossil shark tooth whorl) 2 |
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@N05/34210412012 (archive). It was reviewed on 6 December 2019 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
6 December 2019
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 01:32, 6 December 2019 | ![]() | 3,008 × 1,948 (4.47 MB) | Ser Amantio di Nicolao (talk | contribs) | Transferred from Flickr via #flickr2commons |
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 | NIKON CORPORATION |
---|---|
Camera model | NIKON D70s |
Exposure time | 1/60 sec (0.016666666666667) |
F-number | f/5.3 |
ISO speed rating | 200 |
Date and time of data generation | 14:15, 12 July 2011 |
Lens focal length | 80 mm |
Width | 3,008 px |
Height | 2,000 px |
Bits per component |
|
Pixel composition | RGB |
Orientation | Normal |
Number of components | 3 |
Horizontal resolution | 300 dpi |
Vertical resolution | 300 dpi |
Software used | Adobe Photoshop Elements 13.0 (Macintosh) |
File change date and time | 10:11, 27 April 2017 |
Y and C positioning | Co-sited |
Exposure Program | Not defined |
Exif version | 2.21 |
Date and time of digitizing | 14:15, 12 July 2011 |
Meaning of each component |
|
Image compression mode | 4 |
APEX shutter speed | 5.906891 |
APEX aperture | 4.811985 |
APEX exposure bias | 0 |
Maximum land aperture | 4.7 APEX (f/5.1) |
Metering mode | Pattern |
Light source | Unknown |
Flash | Flash fired, strobe return light detected, auto mode |
DateTime subseconds | 90 |
DateTimeOriginal subseconds | 90 |
DateTimeDigitized subseconds | 90 |
Supported Flashpix version | 1 |
Color space | sRGB |
Sensing method | One-chip color area sensor |
File source | Digital still camera |
Scene type | A directly photographed image |
Custom image processing | Normal process |
Exposure mode | Auto exposure |
White balance | Auto white balance |
Digital zoom ratio | 1 |
Focal length in 35 mm film | 120 mm |
Scene capture type | Standard |
Scene control | None |
Contrast | Normal |
Saturation | Normal |
Sharpness | Normal |
Subject distance range | Unknown |
Serial number of camera | 200638ad |
Lens used | 18.0-200.0 mm f/3.5-5.6 |
Date metadata was last modified | 06:11, 27 April 2017 |
Unique ID of original document | C3B1A3D27A87B70CA9A89F42DF9A36CE |
IIM version | 29,807 |