Eldredgeops rana (formerly Phacops rana) is a species of trilobite from the middle Devonian period. Their fossils are found chiefly in the northeastern United States, and southwestern Ontario.
Because of its abundance and popularity with collectors, Eldredgeops rana was designated the Pennsylvaniastate fossil by the state's General Assembly on December 5, 1988.[2]
Eldredgeops rana can be recognized by its large eyes (which remind some observers of a frog's eyes—the specific name rana is a reference to a common frog), its fairly large size (up to 6 inches long), and its habit of rolling up into a ball like a pill bug ("volvation"). In order to protect themselves from predators, Eldredgeops rana would roll into a ball with its hard exoskeleton on the outside as protection. Many other trilobites possessed the same ability, but Eldredgeops rana nearly perfected it. The slightest amount of sediment would trigger their senses, and Eldredgeops rana would be hidden in a tiny shelter made of its own body.[citation needed] Although this safety feature often helped them to evade predators, occasionally it backfired and the trilobite would be buried under heavy sediment. Their fossils can still be found in balled-up positions 400 million years later.
Fossilisationedit
Eldredgeops rana is found in the northeastern U.S, southwestern Ontario, and in Morocco; North America was attached to the African plate during the Devonian.
The most striking feature of the morphology of Eldredgeops rana and its relatives is their eyes. These differed from the eyes of most trilobites in having comparatively few lenses spaced between deep sclera. The lenses themselves were very rounded instead of largely flat. The eyes were mounted on turret-like structures which could swivel, providing the animal with an almost 360-degree field of view. This type of eye is known as the schizochroal eye.
Distinguishing eye of Eldredgeops rana
Referencesedit
^Burton, C. J.; Eldredge, N. (1974). (PDF). Palaeontology. 17 (2): 349. Archived from the original (PDF) on 2013-11-04.
^Harper, John (2013). "Reflections on Phacops rana (Green), Pennsylvania's State Fossil" (PDF). Pennsylvania Geology. 43 (2): 3–10.
Some of the information in this article was taken from the website A Guide to the Orders of Trilobites, by Sam Gon III.
Picture courtesy of "Valdosta State University Virtual Fossil Museum". Phacops Rana. Retrieved August 22, 2005.
Color reconstruction of Eldredgeops (Phacops) rana at
McRoberts, Christopher A.; Hegna, Thomas A.; Burke, Jeri J.; Stice, Morgan L.; Mize, Steven K.; Martin, Markus J. "Original spotted patterns on Middle Devonian phacopid trilobites from western and central New York".
February 15, 2024
eldredgeops, rana, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, 2011, le. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Eldredgeops rana news newspapers books scholar JSTOR May 2011 Learn how and when to remove this template message Eldredgeops rana formerly Phacops rana is a species of trilobite from the middle Devonian period Their fossils are found chiefly in the northeastern United States and southwestern Ontario Eldredgeops ranaTemporal range Givetian Frasnian PreꞒ Ꞓ O S D C P T J K Pg NScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ArthropodaClass TrilobitaOrder PhacopidaFamily PhacopidaeGenus EldredgeopsSpecies E ranaBinomial name Eldredgeops rana Green 1832 Subspecies 1 E rana rana E rana africana Burton amp Eldredge 1974 E rana crassituberculata Stumm 1953 E rana milleri Stewart 1927 E rana norwoodiensis Stumm 1953 E rana paucituberculata Eldredge 1972 E rana tindoufensis Burton amp Eldredge 1974Because of its abundance and popularity with collectors Eldredgeops rana was designated the Pennsylvania state fossil by the state s General Assembly on December 5 1988 2 Contents 1 Description 2 Fossilisation 3 Phacopid eyes 4 ReferencesDescription edit nbsp Eldredgeops rana fossilsEldredgeops rana can be recognized by its large eyes which remind some observers of a frog s eyes the specific name rana is a reference to a common frog its fairly large size up to 6 inches long and its habit of rolling up into a ball like a pill bug volvation In order to protect themselves from predators Eldredgeops rana would roll into a ball with its hard exoskeleton on the outside as protection Many other trilobites possessed the same ability but Eldredgeops rana nearly perfected it The slightest amount of sediment would trigger their senses and Eldredgeops rana would be hidden in a tiny shelter made of its own body citation needed Although this safety feature often helped them to evade predators occasionally it backfired and the trilobite would be buried under heavy sediment Their fossils can still be found in balled up positions 400 million years later Fossilisation editEldredgeops rana is found in the northeastern U S southwestern Ontario and in Morocco North America was attached to the African plate during the Devonian Phacopid eyes edit nbsp Enrolled Eldredgeops rana from an outcrop of the Middle Devonian Mahantango Formation near Milesburg Pennsylvania with schizochroal eye visibleThe most striking feature of the morphology of Eldredgeops rana and its relatives is their eyes These differed from the eyes of most trilobites in having comparatively few lenses spaced between deep sclera The lenses themselves were very rounded instead of largely flat The eyes were mounted on turret like structures which could swivel providing the animal with an almost 360 degree field of view This type of eye is known as the schizochroal eye nbsp Distinguishing eye of Eldredgeops ranaReferences edit Burton C J Eldredge N 1974 Two new subspecies of Phacops rana Trilobita from the Middle Devonian of North West Africa PDF Palaeontology 17 2 349 Archived from the original PDF on 2013 11 04 Harper John 2013 Reflections on Phacops rana Green Pennsylvania s State Fossil PDF Pennsylvania Geology 43 2 3 10 nbsp Arthropods portal nbsp Paleontology portalSome of the information in this article was taken from the website A Guide to the Orders of Trilobites by Sam Gon III Picture courtesy of Valdosta State University Virtual Fossil Museum Phacops Rana Retrieved August 22 2005 Color reconstruction of Eldredgeops Phacops rana at www emilydamstra comMcRoberts Christopher A Hegna Thomas A Burke Jeri J Stice Morgan L Mize Steven K Martin Markus J Original spotted patterns on Middle Devonian phacopid trilobites from western and central New York Retrieved from https en wikipedia org w index php title Eldredgeops rana amp oldid 1163118320, wikipedia, wiki, book, books, library,
