Leedsichthys
Leedsichthys | |
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Fossil tail fin from the Natural History Museum, London | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | †Pachycormiformes |
Family: | †Pachycormidae |
Genus: | †Leedsichthys Woodward, 1889 |
Type species | |
Leedsichthys problematicus Woodward, 1889
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Species | |
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Leedsichthys is an extinct genus of
The first remains of Leedsichthys were identified in the nineteenth century. Especially important were the finds by the British collector Alfred Nicholson Leeds, after whom the genus was named "Leeds' fish" in 1889. The type species is Leedsichthys problematicus. Leedsichthys fossils have been found in England, France, Germany and Chile. In 1999, based on the Chilean discoveries, a second species was named Leedsichthys notocetes, but this was later shown to be indistinguishable from L. problematicus.
Leedsichthys fossils have been difficult to interpret because the skeletons were not completely made of bone. Large parts consisted of cartilage that did not fossilize. On several occasions the enigmatic large partial remains have been mistaken for stegosaurian dinosaur bones. As the vertebrae are among the parts that have not been preserved, it is hard to determine the total body length. Estimates have varied significantly. At the beginning of the twentieth century, a length of 9 m (30 ft) was seen as plausible, but by its end Leedsichthys was sometimes claimed to have been over 30 m (98 ft) long. Recent research has lowered this to about 16.5 m (54 ft) for the largest individuals. Skull bones have been found indicating that Leedsichthys had a large head with bosses on the skull roof. Fossilised bony fin rays show large elongated pectoral fins and a tall vertical tail fin. The gill arches were lined by gill rakers, equipped by a unique system of delicate bone plates, that filtered plankton from the sea water, the main food source.
Along with its close pachycormid relatives
Discovery and naming
During the 1880s, the gentleman farmer Alfred Nicholson Leeds collected large fish fossils from loam pits near
The
Leeds continued to collect Leedsichthys fossils that subsequently were acquired by British musea. In March 1898, Leeds reported to have discovered a tail which he on 17 March 1899 sold for £25 to the
Leeds had a rival, the collector Henry Keeping [citation needed], who in 1899 tricked pit workers into selling dorsal fin rays by misinforming them that Leeds had lost interest in such finds. Keeping again sold these to the University of Cambridge where they were catalogued as specimen CAMSM J.46873. In September 1901, they were examined by the German palaeontologist Friedrich von Huene, who identified them as tail spikes, Schwanzstacheln, of Omosaurus,[9] the second time Leedsichthys remains were mistaken for stegosaurian bones; Leeds himself was able to disabuse von Huene the same year.[1]
In 2001, students at the
Apart from the British discoveries, finds of a more fragmentary nature continued to be made in Normandy, France. In July 1982, Germany became an important source of Leedsichthys fossils when two groups of amateur palaeontologists, unaware of each other's activities, began to dig up the same skeleton at Wallücke. Remarkably, parts of it were again incorrectly identified as stegosaurian material, of Lexovisaurus.[14] From 1973 onwards, fragmentary Leedsichthys fossils were uncovered in Chile. In March 1994, a more complete specimen was found, SMNK 2573 PAL. In 1999 the Chilean finds were named as a second species, Leedsichthys notocetes, the "Southern Sea Monster".[15] However, Liston later concluded that the presumed distinguishing traits of this species, depressions on the gill rakers, were artefacts caused by erosion;[13] Leedsichthys notocetes would be a junior synonym of Leedsichthys problematicus.[16]
Fossil range
The fossil remains of Leedsichthys have been found in the
Description
Although the remains of over seventy individuals have been found, most of them are partial and fragmentary. The skeleton of Leedsichthys is thus only imperfectly known. This is largely caused by the fact that many skeletal elements, including the front of the skull and the vertebral centra, did not ossify but remained cartilage. Furthermore, those that did ossify were gradually hollowed out during the lifetime of the animal by resorption of the inner bone tissue. In the fossil phase, compression flattened and cracked these hollow structures, making it extraordinarily difficult to identify them or determine their original form.[1]
The head was probably relatively large and wide but still elongated. The snout is completely unknown.
The gill arches are equipped with rows of parallel 3-to-12-centimetre-long (1.2-to-4.7-inch-long)
Large parts of the Leedsichthys fossils consist of bony
Size
Leedsichthys is the largest known member of the
Liston in his studies concluded to much lower estimates. Documentation of historical finds is not unreasonable.
In 2013, Liston and colleagues estimated that the age of the five specimens (PETMG F174, NHMUK PV P10000, GLAHM V3363, NHMUK PV P6921 and NHMUK PV P10156) would have ranged between 19 and 40 years old. The largest specimen, NHMUK PV P10156, on the basis of its gill basket with a preserved width of 114 centimetres (3.74 ft) and height of 154.5 centimetres (5.07 ft), would have been 38 years old (2 years younger than the holotype NHMUK PV P6921) and measured 16.5 metres (54 ft) long.[2] In 2018, Ferron and colleagues estimated that this specimen would have weighed 44.9 metric tons (49.5 short tons).[30]
Phylogeny
Woodward initially assigned Leedsichthys to the
Within the Pachycormidae, a
This cladogram after Friedman et al. shows a possible position of Leedsichtys in the evolutionary tree.[34]
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Paleobiology
Like the largest fish today, the
Much is still uncertain about the life cycle of Leedsichthys. Liston's 2013 study suggested a slow, nearly linear, growth.[2] A French study in 1993 of its bone structure concluded however, that the metabolism was rather high.[35] Also problematic is how Leedsichthys could increase its size quickly during the first year of its life. Teleostei typically lay relatively small eggs and this has been seen as an obstacle for them attaining giant sizes.[36]
In 1986, Martill reported the presence of a tooth of the marine crocodile
In 1999 Martill suggested that a
Recent studies have uncovered some estimations regarding metabolic rate and speed for Leedsichthys. Using data from living teleost fish as a comparison, scientists discovered that Leedsichthys could have cruised along at potential speeds of 11 mph (17.8 km/h) while still maintaining oxygenation of its body tissues.[41][42]
Footnotes
- ^ a b c d e f g h Liston, JJ (2004). An overview of the pachycormiform Leedsichthys. In: Arratia G and Tintori A (eds) Mesozoic Fishes 3 - Systematics, Paleoenvironments and Biodiversity. Verlag Dr. Friedrich Pfeil, München, pp 379–390.
- ^ ISBN 9783899371598.)
{{cite book}}
: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link - ^ Hulke, J.W., 1887, "Note on some Dinosaurian remains in the collection of A. Leeds Esq., of Eyebury, Northamptonshire", Quarterly Journal of the Geological Society of London, 43: 695-702
- ^ a b Woodward, Smith, A (1889). Preliminary notes on some new and little-known British Jurassic fishes. Geological Magazine Decade 3 Volume 6: 448–455.
- ^ Woodward, A.S., 1889, "Notes on some new and little-known British Jurassic Fishes", Annals of the Magazine of natural History, series 6, 4: 405-407
- ^ Woodward, A.S., 1890, "Note on the gill-rakers of Leedsia problematica – a gigantic fish from the Oxford Clay", Geological Magazine December III(7): 292-293
- ^ a b c d e Liston, J.J., 2010, "The occurrence of the Middle Jurassic pachycormid fish Leedsichthys", Oryctos 9: 1-36
- ^ Gunter, M., 2005, Conservation of P.10000: Leedsichthys problematicus. 35 pp.; London (RCA/V&A Conservation)
- ^ Huene, F. von, 1901, "Notizen aus dem Woodwardian-Museum in Cambridge", Centralblatt für Mineralogie, Geologie und Palaeontologie 1901: 715-719
- ^ Douglas Palmer & Hermione Cockburn, 2012, The Fossil Detectives: Discovering Prehistoric Britain, Google eBook, p. 146
- ^ Dawn, A., 2004, "Leedsichthys problematicus", Geology Today 20: 53-55
- ^ Dawn, A., 2004, "Leedsichthys problematicus", The Mercian Geologist, 16(1): 43-45
- ^ a b Liston, J.J., 2007, A Fish Fit For Ozymandias?: The Ecology, Growth and Osteology of Leedsichthys (Pachycormidae, Actinopterygii), Unpublished PhD Thesis. 464 pp. Faculty of BioMedical & LifeSciences, University of Glasgow, Scotland
- ^ Michelis, I., Martin Sander, P., Metzdorf, R. & Breitkreuz, H., 1996, "Die Vertebratenfauna des Calloviums (Mittlerer Jura) aus dem Steinbruch Störmer (Wallücke, Wiehengebirge)", Geologie und Palaeontologie in Westfalen 44: 5-66
- ^ a b Martill, D.M., Frey, E., Caceras, R.P. & Diaz, G.C., 1999, "The giant pachycormid Leedsichthys (Actinopterygii) in the southern hemisphere: further evidence for a Jurassic Atlanto-Pacific marine faunal province", Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 1999: 243-256
- ^ Liston, J.J., 2013, "The plasticity of gill raker characteristics in suspension feeders: Implications for Pachycormiformes", In: G. Arratia, H.-P. Schultze & M. V. H. Wilson (eds.) Mesozoic Fishes 5 – Global Diversity and Evolution pp 121-143, Verlag Dr. Friedrich Pfeil, München
- ^ a b c Liston, JJ (2008a). Leedsichthys des Vaches Noires ... au peigne fin (translation by M-C Buchy) L’Écho des Falaises (=Ech.des Fal.) No.12: 41–49, 2008 ISSN 1253-6946.
- ^ Gouiric-Cavalli, Soledad. "Large and Mainly Unnoticed: The First Lower Tithonian Record of a Suspension-Feeding Pachycormid from Southern Gondwana." Ameghiniana 54.3 (2017): 283-289.
- ^ ISBN 978-3-89937-080-5
- ^ a b Martill, DM (1986). The world's largest fish. Geology Today March–April: 61–63.
- ^ Woodward, Smith, A (1905). A Guide to the Fossil Reptiles, Amphibians, and Fishes in the Department of Geology and Palaeontology of the British Museum (Natural History). Eighth edition. British Museum (Natural History), London. Pp xviii, 110 pages.
- ^ Woodward, A.S., 1917, "Alfred Nicholson Leeds, F.G.S.", Geological Magazine, 6(4): 478-480
- ^ Martill, D.M., 1988, "Leedsichthys problematicus, a giant filter-feeding teleost from the Jurassic of England and France", Neues Jahrbuch für Geologie und Paläontologie Monatshefte 1988 (11): 670-680
- ^ [Ed.] "Catch the 100ft fish", The Mirror, London, England, September 18, 2003
- ^ Liston, JJ & Noè, LF (2004). The tail of the Jurassic fish Leedsichthys problematicus (Osteichthyes: Actinopterygii) collected by Alfred Nicholson Leeds – an example of the importance of historical records in palaeontology. Archives of Natural History 31: 236–252.
- ^ Liston, JJ (2006). From Glasgow to the Star Pit and Stuttgart: A short journey around the world's longest fish. The Glasgow Naturalist 24: 59–71.
- ^ Sloan, C (2004). Big Fish Story. National Geographic Magazine, p. 42. 1/9/2004.
- ^ Liston, JJ, Steel, L & Challands, TJ (2005). Lured by the Rings: Growth structures in Leedsichthys. In: Poyato-Ariza FJ (ed) Fourth International Meeting on Mesozoic Fishes - Systematics, Homology and Nomenclature, Extended Abstracts. Servicio de Publicaciones de la Universidad Autónoma de Madrid/UAM Ediciones, Madrid, pp 147–149
- ^ Liston, JJ (2005). Homologies amongst the fragments: searching for synapomorphies in shattered skulls. In: Poyato-Ariza FJ (ed) Fourth International Meeting on Mesozoic Fishes - Systematics, Homology and Nomenclature, Extended Abstracts. Servicio de Publicaciones de la Universidad Autónoma de Madrid/UAM Ediciones, Madrid, pp 141–145.
- S2CID 134886017.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ^ Arratia, G., 1999, "The monophyly of Teleostei and stem-group teleosts. Consensus and disagreements". –In: Arratia, G. & Schultze, H.-P. (eds.): Mesozoic Fishes 2 – Systematics and Fossil Record: 265-334, München, Dr. Friedrich Pfeil Verlag
- ^ M. Friedmann, 2012, "Parallel evolutionary trajectories underlie the origin of giant suspension-feeding whales and bony fish", Proceedings of the Royal Society B 279: 944-951
- ^ J.J. Sepkoski, 2002, "A compendium of fossil marine animal genera", Bulletins of American Paleontology 363: 1-560
- S2CID 206524637.
- ^ Bardet, N., Pennettier, E., Pennetier, G., Charles, A. & Charles, J., 1993, "Des os énigmatiques à section triangulaire dans le Jurassique Moyen (Callovien) de Normandie", Bulletin trimestriel de la Société géologique de Normandie et des amis du Muséum du Havre 80: 7-10
- ^ Freedman, J.A. & Noakes, L.G., 2002, "Why are there no really big bony fishes? A point-of-view on maximum body size in teleosts and elasmobranchs", Reviews in Fish Biology and Fisheries 12: 403-416
- ^ Martill, D.M., 1986, "The diet of Metriorhynchus, a Mesozoic marine crocodile", Neues Jahrbuch fur Geologie und Paläontologie, Monatshefte 1986: 621-625
- doi:10.3390/fossils2010002.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ^ Friedman, M., K. Shimada, L.D. Martin, M.J. Everhart, J. Liston, A. Maltese and M. Triebold, 2010, "100-million-year dynasty of giant planktivorous bony fishes in the Mesozoic seas", Science 327: 990–993
- ^ Friedman, M., 2011, "Parallel evolutionary trajectories underlie the origin of giant suspension-feeding whales and bony fishes", Proceedings of the Royal Society B, 279: 944-951
- ^ "This ancient fish was bigger than a whale shark—and faster than scientists ever imagined". 2018-05-29.
- ^ Humberto G. Ferrón, Borja Holgado, Jeffrey J. Liston, Carlos Martínez‐Pérez & Héctor Botella, 2018, "Assessing metabolic constraints on the maximum body size of actinopterygians: locomotion energetics of Leedsichthys problematicus (Actinopterygii, Pachycormiformes)", Palaeontology 61(5): 775-783
External links
- For more on the Star Pit dig of 2002-2003 look here and also here where the dig was featured in the BBC-Open University series Fossil Detectives. Archived 2011-06-11 at the Wayback Machine
- For a more accurate reconstruction of Leedsichthys visit Paleocreations. The artist went on to produce the most accurate reconstruction of Leedsichthys to date, which was used on 'Fossil Detectives' (see above).
- Article on Leedsichthys by Darren Naish.
- Profile of Leedsichthys problematicus from the BBC series Sea Monsters
- "Biggest Fish Ever Found" Unearthed in U.K. National Geographic News. Published October 1, 2003.
- Article on the latest discovery of a Leedsichthys problematicus fossil, estimated 22 meters = 72 feet (22 m) long.
- Picture of Leedsichthys problematicus
- Article on Leedsichthys from BBC news