Megalochelys ("great turtle") is an extinct genus of tortoises that lived from the Miocene to Pleistocene. They are noted for their giant size, which is among the largest of any known testudine, with a maximum carapace length over 2 m (6.5 ft) in M. atlas. During the dry glacial periods it ranged from western India and Pakistan (possibly even as far west as southern and eastern Europe) to as far east as Sulawesi and Timor in Indonesia, though the island specimens likely represent distinct species.[4]
One species of Megalochelys,M. atlas, is the largest known tortoise, with a shell length of 2 m (6 ft 7 in) and even 2.7 m (8 ft 10 in), and an approximate total height of 1.8 m (5 ft 11 in).[5] Popular weight estimates for this taxon have varied greatly with the highest estimates reaching up to 4,000 kg (8,800 lb) in some instances.[6] However, weights based on volumetric displacement of the skeleton,[7] or inferences based on two-dimensional skeletal drawings,[8] indicate that M. atlas was probably closer to 1,000 to 2,000 kg (2,200 to 4,400 lb) in mass. M. atlas is thus the largest known tortoise. The only larger turtles were the marineArchelon and Protostega from the Cretaceous Period, and the aquatic, freshwater Stupendemys of the South AmericanLate Miocene. A similarly gigantic tortoise, Titanochelon, is known from the Miocene to Pleistocene of Europe, which had shell lengths of up to 2 m (6 ft 7 in).
Like the modern Galápagos tortoise, M. atlas' weight was supported by four elephantine feet. Like other tortoises, it is thought to have been herbivorous.
Taxonomyedit
M. margae fossilized humerus bone from Saribatue, Wallanae river, South Sulawesi
Megalochelys is the original and valid name for what has been called Colossochelys. It contains three named species with several unnamed taxa.[1]
Megalochelys atlas Falconer and Cautley, 1844[1][3] Late Miocene to Early Pleistocene, India (Sivalik Hills), Myanmar, ?Thailand
Megalochelys cautleyiLydekker, 1889[1][9] Late Pliocene to Early Pleistocene, India (Sivalik Hills) probable nomen dubium.[1]
Megalochelys margae[1] Early Pleistocene, Sulawesi, Indonesia. Size estimation between 1,4-1,9 m long.[1]
Megalochelys sondaari Karl and Staesche, 2007 [1] Early Pleistocene (until 1.7 ma) Luzon, Philippines
The genus is suspected to have gone extinct due to the arrival of Homo erectus, due to staggered extinctions on islands coinciding with the arrival of H. erectus in these regions, as well as evidence of exploitation by H. erectus. The genus was largely extinct by the end of the Early Pleistocene, but persisted on Timor into the Middle Pleistocene.[1]
Stupendemys: the largest freshwater turtle to have ever lived, comparable in size to Megalochelys atlas
Referencesedit
^ abcdefghijRhodin, A.G.J.; Thomson, S.; Georgalis, G.; Karl, H.-V.; Danilov, I.G.; Takahashi, A.; de la Fuente, M.S.; Bourque, J.R.; Delfino M.; Bour, R.; Iverson, J.B.; Shaffer, H.B.; van Dijk, P.P.; et al. (Turtle Extinctions Working Group) (2015). "Turtles and tortoises of the world during the rise and global spread of humanity: first checklist and review of extinct Pleistocene and Holocene chelonians". Chelonian Research Monographs. 5 (8): 000e.1–66. doi:10.3854/crm.5.000e.fossil.checklist.v1.2015. hdl:11336/62240.
^Falconer, H. and Cautley, P.T. 1837. On additional fossil species of the order Quadrumana from the Siwalik Hills. Journal of the Asiatic Society of Bengal 6:354–360.
^ abFalconer, H. and Cautley, P.T. 1844. Communication on the Colossochelys atlas, a fossil tortoise of enormous size from the Tertiary strata of the Siwalk Hills in the north of India. Proceedings of the Zoological Society of London 1844(12):54–84.
^ abcdRhodin, Anders; Pritchard, Peter; van Dijk, Peter Paul; Saumure, Raymond; Buhlmann, Kurt; Iverson, John; Mittermeier, Russell, eds. (2015-04-16). "Turtles and Tortoises of the World During the Rise and Global Spread of Humanity: First Checklist and Review of Extinct Pleistocene and Holocene Chelonians". Conservation Biology of Freshwater Turtles and Tortoises. Chelonian Research Monographs. Vol. 5 (First ed.). Chelonian Research Foundation. doi:10.3854/crm.5.000e.fossil.checklist.v1.2015. ISBN978-0-9653540-9-7.
^Hirayama R, Sonoda T, Takai M, Htike T, Maung Thein ZM, Takahashi A. 2015. Megalochelys: gigantic tortoise from the Neogene of Myanmar. PeerJ PrePrints 3:e961v1 https://doi.org/10.7287/peerj.preprints.961v1
^Orenstein, R. 2001. Survivors in Armor: Turtles, Tortoises, and Terrapins. Key Porter Books Ltd.
^Brown, B. 1931. The Largest Known Land Tortoise. Nat. Hist. Vol. 31:184–187.
^Gregory S. Paul; Guy D. Leahy (1994). (PDF). The Paleontological Society Special Publications. 7: Dino Fest: 177–198. doi:10.1017/S2475262200009515. Archived from the original (PDF) on 20 September 2022.
^Lydekker, R. 1889. Catalogue of the Fossil Reptilia and Amphibia in the British Museum. Part III. Chelonia. London: British Museum of Natural History, 239 pp.
^van den Bergh, Gerrit D.; Alloway, Brent V.; Storey, Michael; Setiawan, Ruly; Yurnaldi, Dida; Kurniawan, Iwan; Moore, Mark W.; Jatmiko; Brumm, Adam; Flude, Stephanie; Sutikna, Thomas; Setiyabudi, Erick; Prasetyo, Unggul W.; Puspaningrum, Mika R.; Yoga, Ifan (October 2022). "An integrative geochronological framework for the Pleistocene So'a basin (Flores, Indonesia), and its implications for faunal turnover and hominin arrival". Quaternary Science Reviews. 294: 107721. Bibcode:2022QSRv..29407721V. doi:10.1016/j.quascirev.2022.107721. hdl:10072/418777. S2CID 252290750.
^Vlachos, Evangelos; Rabi, Márton (December 2018). "Total evidence analysis and body size evolution of extant and extinct tortoises (Testudines: Cryptodira: Pan-Testudinidae)". Cladistics. 34 (6): 652–683. doi:10.1111/cla.12227. PMID 34706483. S2CID 90619565.
April 11, 2024
megalochelys, great, turtle, extinct, genus, tortoises, that, lived, from, miocene, pleistocene, they, noted, their, giant, size, which, among, largest, known, testudine, with, maximum, carapace, length, over, atlas, during, glacial, periods, ranged, from, wes. Megalochelys great turtle is an extinct genus of tortoises that lived from the Miocene to Pleistocene They are noted for their giant size which is among the largest of any known testudine with a maximum carapace length over 2 m 6 5 ft in M atlas During the dry glacial periods it ranged from western India and Pakistan possibly even as far west as southern and eastern Europe to as far east as Sulawesi and Timor in Indonesia though the island specimens likely represent distinct species 4 MegalochelysTemporal range Late Miocene Middle Pleistocene PreꞒ Ꞓ O S D C P T J K Pg NM atlas skeleton at the American Museum of Natural HistoryScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass ReptiliaOrder TestudinesSuborder CryptodiraSuperfamily TestudinoideaFamily TestudinidaeGenus MegalochelysFalconer amp Cautley 1837 1 2 SynonymsColossochelys Falconer amp Cautley 1844 1 3 Contents 1 Description 2 Taxonomy 3 Extinction 4 See also 5 ReferencesDescription editOne species of Megalochelys M atlas is the largest known tortoise with a shell length of 2 m 6 ft 7 in and even 2 7 m 8 ft 10 in and an approximate total height of 1 8 m 5 ft 11 in 5 Popular weight estimates for this taxon have varied greatly with the highest estimates reaching up to 4 000 kg 8 800 lb in some instances 6 However weights based on volumetric displacement of the skeleton 7 or inferences based on two dimensional skeletal drawings 8 indicate that M atlas was probably closer to 1 000 to 2 000 kg 2 200 to 4 400 lb in mass M atlas is thus the largest known tortoise The only larger turtles were the marine Archelon and Protostega from the Cretaceous Period and the aquatic freshwater Stupendemys of the South American Late Miocene A similarly gigantic tortoise Titanochelon is known from the Miocene to Pleistocene of Europe which had shell lengths of up to 2 m 6 ft 7 in Like the modern Galapagos tortoise M atlas weight was supported by four elephantine feet Like other tortoises it is thought to have been herbivorous Taxonomy edit nbsp M margae fossilized humerus bone from Saribatue Wallanae river South SulawesiMegalochelys is the original and valid name for what has been called Colossochelys It contains three named species with several unnamed taxa 1 Megalochelys atlas Falconer and Cautley 1844 1 3 Late Miocene to Early Pleistocene India Sivalik Hills Myanmar Thailand Megalochelys cautleyi Lydekker 1889 1 9 Late Pliocene to Early Pleistocene India Sivalik Hills probable nomen dubium 1 Megalochelys margae 1 Early Pleistocene Sulawesi Indonesia Size estimation between 1 4 1 9 m long 1 Megalochelys sondaari Karl and Staesche 2007 1 Early Pleistocene until 1 7 ma Luzon Philippines Megalochelys sp Middle Late Pleistocene about 0 8 0 12 Mya Timor Indonesia 4 Megalochelys sp Early Pleistocene until 1 2 Mya Java Indonesia 4 Megalochelys sp Early Pleistocene 1 4 1 3 Mya 10 Flores Indonesia 4 Cladistic analysis has suggested that Megalochelys closest living relative is Centrochelys the African spurred tortoise with both also being closely related to Geochelone the star tortoises 11 Extinction editThe genus is suspected to have gone extinct due to the arrival of Homo erectus due to staggered extinctions on islands coinciding with the arrival of H erectus in these regions as well as evidence of exploitation by H erectus The genus was largely extinct by the end of the Early Pleistocene but persisted on Timor into the Middle Pleistocene 1 See also editArchelon A Late Cretaceous marine turtle and the largest turtle yet discovered Stupendemys the largest freshwater turtle to have ever lived comparable in size to Megalochelys atlasReferences edit a b c d e f g h i j Rhodin A G J Thomson S Georgalis G Karl H V Danilov I G Takahashi A de la Fuente M S Bourque J R Delfino M Bour R Iverson J B Shaffer H B van Dijk P P et al Turtle Extinctions Working Group 2015 Turtles and tortoises of the world during the rise and global spread of humanity first checklist and review of extinct Pleistocene and Holocene chelonians Chelonian Research Monographs 5 8 000e 1 66 doi 10 3854 crm 5 000e fossil checklist v1 2015 hdl 11336 62240 Falconer H and Cautley P T 1837 On additional fossil species of the order Quadrumana from the Siwalik Hills Journal of the Asiatic Society of Bengal 6 354 360 a b Falconer H and Cautley P T 1844 Communication on the Colossochelys atlas a fossil tortoise of enormous size from the Tertiary strata of the Siwalk Hills in the north of India Proceedings of the Zoological Society of London 1844 12 54 84 a b c d Rhodin Anders Pritchard Peter van Dijk Peter Paul Saumure Raymond Buhlmann Kurt Iverson John Mittermeier Russell eds 2015 04 16 Turtles and Tortoises of the World During the Rise and Global Spread of Humanity First Checklist and Review of Extinct Pleistocene and Holocene Chelonians Conservation Biology of Freshwater Turtles and Tortoises Chelonian Research Monographs Vol 5 First ed Chelonian Research Foundation doi 10 3854 crm 5 000e fossil checklist v1 2015 ISBN 978 0 9653540 9 7 Hirayama R Sonoda T Takai M Htike T Maung Thein ZM Takahashi A 2015 Megalochelys gigantic tortoise from the Neogene of Myanmar PeerJ PrePrints 3 e961v1 https doi org 10 7287 peerj preprints 961v1 Orenstein R 2001 Survivors in Armor Turtles Tortoises and Terrapins Key Porter Books Ltd Brown B 1931 The Largest Known Land Tortoise Nat Hist Vol 31 184 187 Gregory S Paul Guy D Leahy 1994 Terramegathermy in the time of the titans Restoring the metabolics of colossal dinosaurs PDF The Paleontological Society Special Publications 7 Dino Fest 177 198 doi 10 1017 S2475262200009515 Archived from the original PDF on 20 September 2022 Lydekker R 1889 Catalogue of the Fossil Reptilia and Amphibia in the British Museum Part III Chelonia London British Museum of Natural History 239 pp van den Bergh Gerrit D Alloway Brent V Storey Michael Setiawan Ruly Yurnaldi Dida Kurniawan Iwan Moore Mark W Jatmiko Brumm Adam Flude Stephanie Sutikna Thomas Setiyabudi Erick Prasetyo Unggul W Puspaningrum Mika R Yoga Ifan October 2022 An integrative geochronological framework for the Pleistocene So a basin Flores Indonesia and its implications for faunal turnover and hominin arrival Quaternary Science Reviews 294 107721 Bibcode 2022QSRv 29407721V doi 10 1016 j quascirev 2022 107721 hdl 10072 418777 S2CID 252290750 Vlachos Evangelos Rabi Marton December 2018 Total evidence analysis and body size evolution of extant and extinct tortoises Testudines Cryptodira Pan Testudinidae Cladistics 34 6 652 683 doi 10 1111 cla 12227 PMID 34706483 S2CID 90619565 Retrieved from https en wikipedia org w index php title Megalochelys amp oldid 1209745453, wikipedia, wiki, book, books, library,
