Hiodon woodruffi: Difference between revisions
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==Description== |
==Description== |
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At the time of description the one complete adult male had a body length of {{convert|108|mm|in|abbr=on}}, with the species having a hypothetical upper length of {{convert|110|mm|in|abbr=on}}. |
Baed on the consistent perservation of specimens in lateral views, Wilson determined that both young and adult ''H. woodruffi'' specimens had [[Fish anatomy#Body|laterally compressed]] bodies. At the time of description the one complete adult male had a body length of {{convert|108|mm|in|abbr=on}}, with the species having a hypothetical upper length of {{convert|110|mm|in|abbr=on}}. The holotype fish was suggested to be either an adult female or immature large male, based on the lack of expanded anal rays. There are between 47 and 49 total vertebrae, of which 24 to 25 are [[Vertebra#other animals|caudal]] and 22 to 24 are precaudal vertebrae. |
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Adults of ''Hiodon woodruffi'' have between 12 and 13 rays on the pectoral fins, based on the six observed specimens. The pelvic fins have about 7 total rays, and extend to down the body 2/3 of the way to the anus. Starting just to the front of the where the anal fin starts, and extends towards the tail ending above the rear third of the anal fin. With a triangular outline, the dorsal fin is composed of 13 to 15 branching rays each attached to a vertebra, and the rear most ray is double branched. |
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==References== |
==References== |
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Revision as of 22:07, 13 January 2021
| Hiodon woodruffi Temporal range: Ypresian
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| Hiodon woodruffi fossil SRIC collection | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Hiodontiformes |
| Family: | Hiodontidae |
| Genus: | Hiodon |
| Species: | †H. woodruffi
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| Binomial name | |
| †Hiodon woodruffi Wilson, 1978
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| Synonyms | |
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Eohiodon woodruffi Wilson, 1978 | |
Hiodon woodruffi is an extinct species of bony fish in the mooneye family, Hiodontidae. The species is known from fossils found in the early Eocene deposits of northern Washington state in the United States, first described from the Klondike Mountain Formation as Eohiodon woodruffi. H. woodruffi is one of two Eocene Okanagan Highlands mooneye species, and one of five fish identified in the Klondike Mountain Formation.
Distribution and paleoenvironment
H. woodruffi fossils have been recovered from two locations in the Okanagan highlands, the Horsefly Beds near Horsefly, British Columbia and the several exposures of the Klondike Mountain Formation in northern Ferry County, Washington. Both sites represent upland lake systems that were surrounded by a warm temperate ecosystem and nearby volcanism.[1]
History and classification
The earliest find, which were later identified as H. woodruffi, were specimens collected by Canadas first vertebrate paleontologist Lawrence Lambe in 1906 from Horsefly.[2]
Fossils of Hiodon woodruffi were first collected in the Klondike Mountain Formation of Washington in the 1960s. One set of fish was collected from the Toroda Creek Graben northwest of Republic by R. C. Pearson, and tentatively identified by paleoichthyologist David Dunkle as members of several genera including the Aphredoderid Tricophanes. Pearson sent almost all of the specimens collected to the Smithsonian, but the fossils were never accessioned into the collections and are now considered lost. Pearson did retain one "Tricophanes" fossil from the initial collection which was later donated to the USGS collections.[3] During the same decade, a collection of fish from near the Tom Thumb Mine in Republic was compiled by the young[4] resident R. Woodward. This collection was subsequently donated to the University of Alberta paleontology department by Woodwards family in 1977. During the summers of 1976 and 1977 the University of Alberta also conducted field collecting in both the Toroda Creek and Republic areas, yielding a number of fossil fish material, including a single hiodontid.[3]
The Okanagan highland hiodontid fossils were studied in detail by paleoithyologist Mark Wilson, of the University of Alberta, with a monograph overview of the British Columbian Eocene fish fauna and redescription of H. rosei being published in 1977,[5] followed by a smaller paper in 1978 containing the H. woodruffi description.[3] The type description of H.woodruffi was published in the May 1978 issue of the Canadian Journal of Earth Sciences. The etymology of the species name woodruffi was chosen in recognition of the Woodruff family for the collection and donation of the specimens studied. Wilson designated University of Alberta specimen UA 13227A & 13227B, collected during the 1976 field work at the Tom Thumb mine as the holotype[3] and also designated a series of topotype specimens in the type series. Specimens UA 13241, 13244, 13250, 13262 and 1326 were all collected by R. Woodruff, while specimen UA 13225 was collected during the 1976 field season. Additionally Wilson referred a group of other specimens to the species which were not included in the type series, USGS El-2185, collected by Pearson in the 1960s and four specimens from Horsefly.[3] H. woodruffi coexisted with four other fish species in the Klondike Mountain Formation lake system[6][7]
A reassessment and redescription of Hiodontidae was completed by Hilton and Grande in 2008. They noted that the known osetological morphology range of the species assigned to Eohiodon were within the osteology spectrum seen in modern Hiodon individuals. This merging of Eohiodon into Hiodon resulted in the species being moved to Hiodon woodruffi as the accepted binomial.[8] Hilton and Grande examined specimens from the Okanagan Highlands as well as specimens refered to the species which had been found in the Kishenehn Formation, and noted that the proposed merging of Hiodon falcatus from the Green River Formation was not accepted, based on differences in osteology.[8]
Age
When the first fossils were collected the Klondike Mountain formation was though to be late Oligocene in age. Potassium-argon radiometric dating of samples taken near the Tom Thumb mine in 1966 resulted in a tentative 55 million years old age. Further refinement of sample dating has yielded an approximately Early Eocene, Ypresian age, being radiometrically dated as 49.4 million years old.
The Kishenehn Formation in Northwestern Montana has been dated to approximately 46.02 million years old[9] based on potassium-argon of the Coal Creek member.[10]
Description
Baed on the consistent perservation of specimens in lateral views, Wilson determined that both young and adult H. woodruffi specimens had laterally compressed bodies. At the time of description the one complete adult male had a body length of 108 mm (4.3 in), with the species having a hypothetical upper length of 110 mm (4.3 in). The holotype fish was suggested to be either an adult female or immature large male, based on the lack of expanded anal rays. There are between 47 and 49 total vertebrae, of which 24 to 25 are caudal and 22 to 24 are precaudal vertebrae.
Adults of Hiodon woodruffi have between 12 and 13 rays on the pectoral fins, based on the six observed specimens. The pelvic fins have about 7 total rays, and extend to down the body 2/3 of the way to the anus. Starting just to the front of the where the anal fin starts, and extends towards the tail ending above the rear third of the anal fin. With a triangular outline, the dorsal fin is composed of 13 to 15 branching rays each attached to a vertebra, and the rear most ray is double branched.
References
- ^ Archibald, S.; Greenwood, D.; Smith, R.; Mathewes, R.; Basinger, J. (2011). "Great Canadian Lagerstätten 1. Early Eocene Lagerstätten of the Okanagan Highlands (British Columbia and Washington State)". Geoscience Canada. 38 (4): 155–164.
- ^ Wilson, M. (1996). "Fishes from Eocene lakes of the interior". In R. Ludvigsen (ed.). Life in stone: a natural history of British Columbia’s fossils. Vancouver, BC: The University of British Columbia Press. pp. 213, 215.
- ^ a b c d e Wilson, M. (1978). "Eohiodon woodruffi n. sp.(Teleostei, Hiodontidae), from the Middle Eocene Klondike Mountain Formation near Republic, Washington". Canadian Journal of Earth Sciences. 15 (5): 679–686. doi:10.1139/e78-075.
- ^ Wilson, M. (1996). "The Eocene fishes of Republic, Washington". Washington Geology. 24 (2): 30–31.
- ^ Wilson, M. (1977). "Middle Eocene freshwater fishes from British Columbia". Life Sciences Contributions, Royal Ontario Museum. 113: 1–66.
- ^ Wilson, M. (1979). "A second species of Libotonius (Pisces: Percopsidae) from the Eocene of Washington State". Copeia. 1979 (3): 400–405.
- ^ Wilson, M. (1982). "A new species of the fish Amia from the middle Eocene of British Columbia". Palaeontology. 25 (2): 413–424.
- ^ a b Hilton, E. J.; Grande, L. (2008). "Fossil Mooneyes (Teleostei: Hiodontiformes, Hiodontidae) from the Eocene of western North America, with a reassessment of their taxonomy". Geological Society, London, Special Publications. 295: 221–251. doi:10.1144/sp295.13.
- ^ Lapolla, J. S.; Greenwalt, D. E. (2015). "Fossil ants (Hymenoptera: Formicidae) of the Middle Eocene Kishenehn Formation". Sociobiology. 62 (2): 163–174.
- ^ Greenwalt, D. E.; Rose, T. R.; Siljestrom, S. M.; Goreva, Y. S.; Constenius, K. N.; Wingerath, J. G. (2014). "Taphonomy of the fossil insects of the middle Eocene Kishenehn Formation". Acta Palaeontologica Polonica. 60 (4): 931–947.