A nearly-complete encyclopedia of underwater cryptozoological knowledge


Sucuriju Gigante / Giant Anaconda

Sucuriju Gigante is a legendary giant anaconda said to be found in the jungles and rivers of South America, with some legends also active in the Democratic Republic of the Congo.  It is a predatory snake ranging in length from 42 feet to 164 feet.  It is amphibious and several sightings have been made by swimmers.  The giant anaconda is sometimes described as having the width of a mere normal anaconda, but the length of several buses.  Some reports tell of large eyes.


The famous Amazon explorer Colonel Percy H. Fawcett, while on one of his expeditions to find El Dorado in the Amazon, sighted a giant anaconda one day.  He and his men at first mistook it for a dead tree on the edge of the slow-moving river, but it started undulating toward the canoes.  According to David Grann in The Lost City of Z,

"It was bigger than an electric eel, and when Fawcett's companions saw it they screamed.  Fawcett lifted his rifle and fired at the object until smoke filled the air.  When the creature ceased to move, the men pulled a canoe alongside it.  It was an anaconda.  In his reports to the Royal Geographical Society, Fawcett insisted that it was longer than sixty feet ('Great Snakes!' blared one headline in the British press) . . ." (81).

Grann dismisses the claim as mistaken, believing that Fawcett overestimated the length of the anaconda's submerged section.

On October 29, 1929, Father Victor Heinz saw a huge snake swimming in the Amazon River near Alenquer, Brazil.

In 1932, this photo was taken of a supposed Sucuriju Gigante which was killed in Brazil near the Venezuelan border.  Judging by the notes on the picture, the diameter was reported at more than two-and-a-half feet and the length at over 131 feet.

In 1948 or '49 Joaquim Alencar took this photo of a supposedly 115-foot snake swimming in Rio Guaporé (which runs along the Bolivia-Brazil border) near Rio Abuna in the Amazon basin.
In 1977, Vicente de Oliveira Amarilho saw a huge snake with horns and greenish eyes on the Rio Purus, an Amazon tributary.

The largest known anacondas can reach 25 feet.  The largest known snake in the world is just under 33 feet, India's reticulated python Python reticulatus  

Eocene epoch: Chubutophis in Albino 22 feet young and 36 feet adult.  But that was tens of millions of years ago.

In 2009, scientists discovered remains of the world's biggest snake.  Columbia: 43-foot Titanoboa snake Titanoboa cerrejonensis (longer than a bus) changed scientists' ideas about how big a snake could be.  2,500 pounds.  Modern boas and ancondas average less than 20 feet and max 30 feet.  Ate crocodiles and giant turtles.  It is as long as the largest known t-rex.  58-60 million years ago.  However, it seems unlikely that a snake that big to survive because scientists estimate the tropical climate had to be 6 to 8 degrees warmer than today for the snake to survive.  The warmer the climate, the larger cold-blooded animals can be.

But according to  Austin Whittall at Patagonian Monsters, Adriana María Albino wrote in a 1991 paper, Patagonia: 45-60 feet, not much is known since the only remnant of the snake is an incomplete vertebrae.  This paper could not be found.
Madtsoia bai Argentina, Eocene once estimated to be 27 feet long.
Madtsoia camposi Brazil, Paleocene

South America

"Science Today" Vol 3 N ° 14 / June to August 1991.

Grann, David. The Lost City of Z: a Tale of Deadly Obsession in the Amazon. New York: Doubleday, 2009. Print.

Murphy JC, Henderson RW. 1997. Tales of Giant Snakes: A Historical Natural History of Anacondas and Pythons. Krieger Pub. Cous. ISBN 0894649957.

See Borneo Monster
See Culibron
See some contemplation on possible connections at Patagonian Monsters

To probe:







Arthur C. Clarke's Mysterious World, Simon Welfare & John Fairley
Claws, Jaws, and Dinosaurs, William J. Gibbons and Dr. Kent Hovind

  1. Dr. Heuvelmans', Bernard, "On the Track of Unknown Animals"
  2. Dinsdale, Tim, "Monster Hunt" 1972
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- 1993. Snakes from the Paleocene and Eocene of Patagonia (Argentina): paleoecology and coevolution with mammals. Historical Biology 7, 51-69.
- 1991. Serpientes gigantes en la Patagonia. Ciencia Hoy, 3(14): 58-63. Read a fragment (in Spanish) Here
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Andrews, C. W. 1901. Preliminary note on some recently discovered extinct vertebrates from Egypt (Part II). Geological Magazine (Dec. 4) 8, 434-444.
Gasparini, Z. 1993. New Tertiary sebecosuchians (Crocodylomorpha) from South America: phylogenetic implications. Historical Biology 7, 1-19.
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Heuvelmans, B. 1995. On the Track of Unknown Animals. Kegan Paul International, London.
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Rage, J.-C. 1983. Palaeophis colossaeus nov. sp. from the Eocene of Mali, with remarks on the genus problem within the Palaeophinae. Comptes Rendu de l'Academie des Sciences, Paris, Serie II 296, 1741-1744.
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Scanlon, J. D. 2003. The basicranial morphology of madtsoiid snakes (Squamata, Ophidia) and the earliest Alethinophidia (Serpentes). Journal of Vertebrate Paleontology 23, 971-976.
- . 2005. Cranial morphology of the Plio-Pleistocene giant madtsoiid snake Wonambi naracoortensis. Acta Palaeontologica Polonica 50, 139-180.
- . 2006. Skull of the large non-macrostomatan snake Yurlunggur from the Australian Oligo-Miocene. Nature 439, 839-842.
- . & Lee, M. S. Y. 2000. The Pleistocene serpent Wonambi and the early evolution of snakes. Nature 403, 416-420.
- . & Lee, M. S. Y. 2002. Varanoid-like dentition in primitive snakes (Madtsoiidae).
Journal of Herpetology 36, 100-106.
Seiffert, E. R. 2006. Revised age estimates from the later Paleogene mammal faunas of Egypt and Oman. Proceedings of the National Academy of Sciences 103, 5000-5005.
Smith, M. J. 1990. Wonambi naracoortensis. In Rich, P. V. & van Tets, G. F. (eds) Kadimaka. Extinct Vertebrates of Australia. Princeton University Press (Princeton, New Jersey), pp. 156-159.