File:Odontopleurid trilobite cheek (Arnheim Formation, Upper Ordovician; Middletown, Ohio, USA).jpg

From Wikimedia Commons, the free media repository
Jump to navigation Jump to search

Original file (982 × 729 pixels, file size: 518 KB, MIME type: image/jpeg)

Captions

Captions

Add a one-line explanation of what this file represents

Summary

[edit]
Description
English: This fossil trilobite fragment is from the famous Cincinnatian Series of the tristate area of Ohio-Kentucky-Indiana. Rocks in the Cincinnatian were deposited in relatively shallow marine facies during the Late Ordovician. The Cincinnatian succession is mostly interbedded limestones and shales. Most of the limestones are event beds (= tempestites), deposited during ancient storms.

Trilobites are extinct marine arthropods. They first appear in Lower Cambrian rocks and went extinct at the end of the Permian. Trilobites had a calcitic exoskeleton and nonmineralizing parts underneath (legs, gills, gut, etc.). The calcite skeleton is most commonly preserved in the fossil record, although soft-part preservation is known in some trilobites (Ex: Burgess Shale and Hunsruck Slate). Trilobites had a head (cephalon), a body of many segments (thorax), and a tail (pygidium). Molts and carcasses usually fell apart quickly - most trilobite fossils are isolated parts of the head (cranidium and free cheeks), individual thoracic segments, or separated pygidia. The name "trilobite" was introduced in 1771 by Johann Ernst Immanuel Walch and refers to the tripartite division of the trilobite body - it has a central axial lobe that runs longitudinally from the head to the tail, plus two side lobes (pleural lobes).

Seen here is the librigena ("free cheek") of an odontopleurid trilobite, possibly Acidaspis. Odontopleurids are distinctive in being highly spinose - note the spines along the margin of this sclerite.

Classification: Animalia, Arthropoda, Trilobite, Polymerida, Odontopleuridae

Stratigraphy: float from the Arnheim Formation, lower Richmondian Stage, upper Cincinnatian Series, upper Upper Ordovician

Locality: loose piece from roadcut along Breiel Boulevard, immediately south of the Route 73-Breiel Boulevard intersection (bottom of the hill), Middletown, northeastern Butler County, southwestern Ohio, USA (vicinity of 39° 32' 36.60" North latitude, 84° 20' 41.41" West longitude)
Date
Source https://www.flickr.com/photos/47445767@N05/49997431261/
Author James St. John

Licensing

[edit]
w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 2.0 Generic license.
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@N05/49997431261. It was reviewed on 13 October 2020 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0.

13 October 2020

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current01:54, 13 October 2020Thumbnail for version as of 01:54, 13 October 2020982 × 729 (518 KB)Ser Amantio di Nicolao (talk | contribs)Uploaded a work by James St. John from https://www.flickr.com/photos/47445767@N05/49997431261/ with UploadWizard

There are no pages that use this file.

Metadata